Marks Daily Apple
Serving up health and fitness insights (daily, of course) with a side of irreverence.
9 Jul

The Evidence Continues to Mount Against Chronic Cardio

Chronic CardioIt’s been awhile since I did a post on chronic cardio. I had a good string of them going several years ago, and I thought I’d done a good job explaining why I was so opposed to excessive endurance training. Despite my attempts to clarify, though, I still receive a lot of questions and comments about cardio. People just have a tough time divorcing themselves from the notion that cardio – as much as you can cram into your schedule – is the key to health and fitness. I don’t blame them, really. It’s conventional wisdom, after all, and it’s what I thought for years and years. Clearly, another post is needed.

Evidence against chronic cardio continues to mount, so there’s a lot to cover. But before we get to all the research, I have a few thoughts about the heart.

Here’s the thing about the heart: being an involuntary muscle, it has no say in the matter. It pretty much feels nothing, too. It’s along for the ride. Just like the liver, kidneys, pancreas, thyroid, adrenals, etc., the heart responds to biochemical signals. It’s a demand organ. Minor changes in blood chemistry (epinephrine, cortisol, insulin, lactic acid, hemoglobin-depleted RBC’s, to name a few) cause it to respond by beating faster or slower, forcefully or not, to keep pace with the muscles’ (and other organs’) demand for oxygen and fuel. During exercise, it’s the brain that starts this whole process with a (usually) conscious decision: “I think I’ll run to that tree.” That thought prompts the muscles of the legs to start moving faster and the arms to pump. The new, increased demand for oxygen and added fuel (over and above normal resting metabolism) signals the heart to start to fulfill the demand, to pump harder and faster. It’s obliged to do so. Period. No choice. That’s also why it’s always a bit behind schedule: it takes more than a few seconds to ramp itself up once the action begins and a few seconds or minutes (or hours, in the case of an over-trainer) to ramp down, once it’s over.

The problem with chronic cardio is that we can force our brains to override some of the tiredness (no pain, no gain, pal) and discomfort in the legs – and to a certain extent even the lungs – and keep doing these hard endurance workouts incessantly day in and day out. The ostensible limiting factor is the ability to burn fat or, at the very least, the amount of glycogen still left in our muscles. That’s what eventually brings us to a halt, frequently because we have willed ourselves to keep going through the wall at all costs. But the heart is often over-worked in this scenario, just trying to keep up with that “inhuman” (and inhumane) desire to run, cycle, or swim further and faster in pursuit of…what? A medal? A ribbon? Bragging rights? It can’t say no. It attempts to do as we bid it. And because the heart feels little-to-no pain – unless, perhaps, it feels the REAL pain of a heart attack – it very often suffers silently as a result without us ever knowing. The walls of the heart start to hypertrophy over time the same way a biceps muscle does when you do curls. But do a few too many curls and your biceps will get sore quickly. Force yourself to do a few more and you could even tear something and be out of contention for a few weeks. We know when to stop before that bicep tears.

Cardiac muscle doesn’t tear that way when over-worked, but it does enlarge and thicken with chronic overuse. In some – most – people the thickening is probably not life-threatening, but in some cases, as with dozens of world class athletes I have personally known, this thickening can cause all manner of issues later in life. Atrial fibrillation has become a mild epidemic in my generation of life-long aerobicizers; several of my friends have had pacemakers or defibrillators implanted before the age of 40 to head-off those sporadic life-threatening cardiac enervation problems. A few more friends have lost significant cardiac function and a few have died.

But don’t take my word for it. The silent epidemic of heart issues among endurance athletes is getting serious attention in the research community. Let’s take a look at some of the latest research.

Cardiac Arrhythmias

Cardiac arrhythmias are abnormal electric activities of the heart. An arrhythmia can describe a heart that beats too fast, too slowly, too irregularly, or too “fluttery.” An arrhythmia doesn’t always indicate or foretell heart trouble, but it’s a common risk factor. One of the more common varieties is atrial fibrillation (AF), which describes a fast, irregular heartbeat. AF is strongly linked to stroke and cognitive decline.

Endurance athletes are at a greater risk for atrial fibrillations than the general, non-running public. One recent study of cross country skiers even found that the best athletes, the top performers, were more likely to have cardiac arrhythmias than the rest. Moderate exercisers, meanwhile, are at a lower risk for AF than the general, non-running public. A recent comprehensive study offers several potential explanations for the increased risk:

  • Increased fibrosis (scar tissue formation) in the heart.
  • Myocardial injury to the heart, as evidenced by post-training elevated cardiac biomarkers typically used to diagnose injury. Probably not a big deal so long as you recover fully from your training, but most cardio junkies can’t wait that long to log more miles.
  • Excessive amounts of inflammatory markers brought on by training. These markers have been linked to AF.

Endurance-related AF usually starts off infrequent. The older you get and the more miles you log, the more entrenched and regular your atrial fibrillation may get. Some studies found that around 40% of athletes with AF eventually progress to persistent AF, where it’s happening on a regular basis. That’s the troubling kind of AF that may presage serious cardiovascular problems, like stroke.


It’s totally counterintuitive to think that endurance athletes are at risk for arterial plaque. “You mean to tell me that the wispy greybeard whizzing past my house in short shorts every evening could have clogged arteries? No way.” Maybe, just maybe.

A 2011 study found evidence of carotid and peripheral atherosclerosis in a group of marathoners. Although there was no control group of non-runners in that study, another study compared the arteries of marathon runners to a control group of sedentary non-marathoners. Marathoners had more calcified plaque in their coronary arteries, which has been linked to stroke and dementia. The tricky thing about these cases is that endurance athletes with atherosclerosis don’t evince the regular signs. Whereas your typical sedentary guy with extensive atherosclerosis will probably have all the hallmarks (metabolic syndrome, abdominal obesity, hypertension, etc.), marathon runners with atherosclerosis don’t fit the traditional cardiovascular risk profile.

It might be time to add “trains for endurance athletics” to the list of risk factors.

Oxidative Stress/Overtraining

It’s no secret that endurance training induces oxidative stress on the athlete. That’s how we get better – by encountering a stressor, being broken down a bit, and then recovering stronger than before so that the next time we encounter the stressor, we’ll be better than the last time. Whether we’re talking strength training, marathon running, cycling, gymnastics, martial arts, or even studying for a trigonometry class, we have to challenge our physiology to get better, and challenges to the physiology mean oxidative stress. Problems arise when we don’t let up, when we keep the intensity elevated and the days off few and far between. We’re constantly in that post-workout state, and it starts to look like chronic oxidative stress for all intents and purposes. Even if our times are improving, we’re not truly recovering. It’s a two steps forward, one step back kind of thing.

So. Those are just a few of the reasons I am no fan of chronic cardio (and don’t get me started on the bad backs, osteoarthritis, hip and knee replacements and chronic tendonitis among my former elite endurance peers). A strong will can be a great thing for survival, for business and for relationships, but it can also get you in trouble if you don’t pay attention to your training load.

Having said all that, I am still a big fan of weights, of brief, intermittent interval training and I am all for doing a fair amount of mixed low-level cardio, the kind that doesn’t overstress the heart or involve so much repetitive joint motion that it causes chronic injury. That makes sense in an ancestral context. You’re expending energy at a high rate, but you’re not going long enough that it becomes a liability. Or, if you’re going long, you’re taking it easy enough that you have the energy to make it back home, possibly carrying food.

I’m not even against a long training run or ride once in a while, provided you are trained, rested and allow enough recovery afterwards. I’m even OK with running marathons occasionally or jumping into a short triathlon now and then. As a species, we obviously have the capacity to go long and relatively hard every now and again. It’s the chronic, day-in, day-out long, hard stuff that is counter-productive. If you did that twenty thousand years ago, when your next meal – and that of your entire family/tribe – was on the line, when calories were somewhat precious, when you didn’t have an air-conditioned caravan of trainers, massage therapists, and coolers filled with electrolyte drinks following along after you, you’d be foolish. You simply wouldn’t do it.

That we can run marathons (and do other stupid things) and know that we’ll get out alive is a luxury of modern living. There are so many other less damaging ways to achieve what I would call high-level adaptive fitness by using a variety of training methods, all of which can be cardio-protective and joint strengthening when done the right way in at the appropriate times. Heck, when it comes to hypertension, blood lipids, and type 2 diabetes, walking is just as effective as running – without the potential downsides. Everyone can walk. Everyone thinks they can run, but running is a skill that must be learned. To run with poor form is to welcome injury, doubly so if you’re running an excessive amount. And all this will be addressed in detail in my forthcoming book, Primal Endurance. For now, use your brain and listen to your body.

My point, of course, is that the human organism is made for short, intense bursts of activity laid atop a foundation of frequent slow moving. We aren’t “supposed” to run as hard as we can for two or three hours. We’re not supposed to run with the express purpose of “burning calories.” We can certainly choose to do those activities, and we’ll become adapted (or perhaps inured) to them, and they may even make us “fit,” but they’re not the healthiest, most efficient path to fitness. Chronic cardio is the meandering, roundabout trail that will get you there with a ton of bruises, scratches, a tick or two, and a sprained ankle. Oh, and you might get eaten by a bear along the way.

Your choice.

Thanks for reading, folks. I’d love to hear your thoughts on cardio, both chronic and otherwise. Let me know in the comment section!

You want comments? We got comments:

Imagine you’re George Clooney. Take a moment to admire your grooming and wit. Okay, now imagine someone walks up to you and asks, “What’s your name?” You say, “I’m George Clooney.” Or maybe you say, “I’m the Clooninator!” You don’t say “I’m George of George Clooney Sells Movies Blog” and you certainly don’t say, “I’m Clooney Weight Loss Plan”. So while spam is technically meat, it ain’t anywhere near Primal. Please nickname yourself something your friends would call you.

  1. So the secret lies somewhere between eating Snackwells on the couch and running marathons!

    Groktimus Primal wrote on July 9th, 2013
    • +1000

      I tried to explain this to a chronic cardio friend (she’s already had joint surgery at 35!) but it gets lost.

      Amy wrote on July 9th, 2013
      • Yeah, I have a sister-in-law who at 40 is physically worn out, has had joint surgery multiple times, thyroid cancer, hair is thinning, can’t sleep, etc but says she will keep on running even if she has only stubs to go on. Should I mention she won’t give up her low fat high carb diet either?

        Kayu wrote on July 9th, 2013
        • Genetics probably has a lot to do with your sister-in-law’s poor condition at age 40 as well.

          Mike D. wrote on November 21st, 2015
    • LMAO om nom nom!

      whorekitten wrote on July 9th, 2013
  2. This sounds like yet another case of too much of something being just as dangerous as too little. Thank god we all know where the sweet spot is now!

    Wenchypoo wrote on July 9th, 2013
    • Yes, this is an interesting post considering we’re in the middle of Tour de France fever – ultimate in chronic cardio?
      I enjoy my once-a-week long 14km run, I run along the river, listen to podcasts and take it easy Yes, I find it relaxing. But any more running than that or if I train hard, I get grumpy, sore and over it very quickly.

      Madeleine wrote on July 9th, 2013
  3. I ran for years; from cross country in high school to marathon running into my 30s. I thought getting sick, tired and exhausted was all part of the journey to strengthen my physically and mentally. I finally broke down and quit once I came across MDA. How could I not listen to a former elite runner, right?

    James wrote on July 9th, 2013
    • From one who has done marathons and martial arts I always thought that training was as very well described – ” we have to challenge our physiology to get better, and challenges to the physiology mean oxidative stress.”

      I agree entirely with – ” Problems arise when we don’t let up, when we keep the intensity elevated and the days off few and far between”

      I have seen a lot of people break down because they do not give the body sufficient rest


      John Ward wrote on July 9th, 2013
  4. I wonder if Crossfit’s programming falls into “brief, interval training,” because sometimes I feel like the metcons are too much.

    mike wrote on July 9th, 2013
    • When i quit doing Crossfit everyday my bodyfat percentage dropped and my sex drive skyrocketed. N=1, but I’m never going back. Chronic HIIT is worse than Chonic cardio in my opinion.

      MattyT wrote on July 9th, 2013
      • I fell in love with you a little bit when I read your last sentence. That is all.

        Kat wrote on July 10th, 2013
    • There was a great post on a while back that pointed out that Crossfit, done wrong, is just trading chronic cardio on a treadmill for chronic cardio with weights! I have been in a Crossfit gym for almost three years, and have really plateaued from the complete randomization and too-intense metcons three times a week. My current plan is to metcon only one day a week, and work on my olympic lifts the other days. I also run ultras, which I would argue are not chronic cardio because they are done at such a low pace, I stay in the fat-burning zone with a relatively low heart rate. “Move frequently at a slow pace”

      David Pryor wrote on July 9th, 2013
      • David, from my experience it does not really matter what running events you do (I went from 21/42K to ultras myself) but what you do in the training phase 😉

        Martin wrote on July 9th, 2013
        • I agree, and now realize my post was not very clear. I actually don’t “train” very much for the events I do, short of long runs (damned near hikes) on the weekend, very few miles of faster-paced stuff during the week, and Crossfit / weight training. Not a lot of high heart-rate tempo runs, which is what I think Mark has in mind with his criticism of chronic cardio.

          David Pryor wrote on July 9th, 2013
      • Wow. I just joined a cross fit gym and was wondering the same thing with cronic cardio in mind. You mentioned metcons and ultras?have me a lot to research. Thank You very much!!

        James wrote on October 30th, 2013
    • It definitely doesn’t, IMHO. Those WODs are simply too long for “metabolic-conditioning”. The sub-10-minute workouts seem okay, but I see plenty of them last 20 minutes and longer.

      Basically, you’re pushing your glycolytic pathway to the max (AKA, sugar-burning metabolism) when you get into these prolonged bouts of Crossfit. If I am correct, this is the same thing as running on the treadmill for an hour. In my writings, you can tell that I’m definitely not a fan of Crossfit –

      In response to David Pryor, Robb Wolf is totally on point. In addition to being totally shunned by big-shots who run CrossfitHQ, Robb Wolf unaffiliated from Crossfit because his gym focuses on strength, power, and super-short metcons.

      Mark P wrote on July 9th, 2013
  5. Hi Mark,

    Love the website and read it daily. However, I don’t get your obsession with telling people to avoid chronic cardio! I’m sure that the vast majority of people out there are not training for marathons at an elite level. What seems more likely is that you’ll turn someone off from training for their first 5k or 10k or half-marathon out of fear of doing more harm than good! I know you often preach to “move often at a slow pace”, but I think it would be nice to supplement these articles with more encouragement to do healthy amounts of cardio.

    Brian wrote on July 9th, 2013
    • I’d have to agree with you here. I just got out of high school where I ran cross country and track and while I was never the fastest, I was miles ahead of my buddies that ran extra miles after practice or 20+ miles over the weekend. It was a rule that I ran slowly in practice and did no weekend running and almost always beat the guys that did. The only time I didn’t win was against a genetic freak who could run three times as much as the rest of us and keep going.

      Dalton K. wrote on July 9th, 2013
      • Mark,
        embedded in one of the above posts is a very important piece of the puzzle. With chronic cardio we have to distinguish between fast and high intensity. The real issue is dose (time x intensity). Many coaches advocate their elite athletes working at low intensity for the bulk of their training and this low level intensity may be very fast by non-elite standards. For example, a friend of mine while training for the Olympic marathon trials would do the bulk of his miles at a pace that would allow him to comfortably carry on a conversation with me while I was completely unable to reply. I’m at 90% and he is at 70% even though the pace was 7min/mile. An individual who is new to exercise may be up around 80% max HR with a brisk walk. The issue is intensity level more than actual speed. A heart rate monitor is very effective for helping people get a feel for training intensity and especially seeing how intensity creeps up during the course of a run over time. You my start at a pace that is 70% and may finish at 85% 60 minutes later.

        Ken wrote on July 10th, 2013
      • Mark, thanks for linking those posts again. I actually enjoy running, but then a chronic cardio post comes up and I think, poop, I’m killing myself. The posts that you linked above remind me that when I go for an easy jog because I want to, and it’s nice and slow, it’s not actually chronic cardio.

        I still love the 4,000-calories-a-week post. It takes a LOT of exercise to burn that much!

        Deanna wrote on July 11th, 2013
    • “I think it would be nice to supplement these articles with more encouragement to do healthy amounts of cardio.”

      I think that’s exactly what he did when he said “walking is just as effective as running” and “everyone can walk.” His point is that running has become the most recommended form of “fitness” in America, even though most people don’t know how to do it properly and most people overdo it and that a couple of decades of doing it wrong can lead to serious issues, even among non-elite athletes. Running is something humans do when they want to catch something or get away from something. If you want to have fun and get some exercise, spouse-wrestling is a much better use of time. 😉

      Mantonat wrote on July 9th, 2013
      • I thought spouse wrestling was chronic cardio

        Randy Stimpson wrote on July 9th, 2013
        • I think you must be doing it wrong, spouse wrestling is definitely HIIT.

          Dzoldzaya wrote on July 9th, 2013
    • “I’m sure that the vast majority of people out there are not training for marathons at an elite level. What seems more likely is that you’ll turn someone off from training for their first 5k or 10k or half-marathon out of fear of doing more harm than good! ”

      Someone might skip a totally pointless running contest in favor of daily walking or learning to weight lift properly? Quelle horreur! :)

      Unfortunately, I disagree. I know many people who completely equate fitness=running, one who is determined to destroy her health over it. These type of posts are very much needed occasionally.

      Amy wrote on July 9th, 2013
    • I would personally like to see a lot more information about middle of the road cardio. There is a lot of wiggle room between walking and 100 miles a week. It can’t be all bad.

      Lea wrote on July 9th, 2013
      • Lea, spoken like a true Cortisol junkie.

        Nocona wrote on July 9th, 2013
    • If you want the cardiac and fat burning benefits of cardio, powerlifting is a much better way to get them, and you don’t risk overtraining. Likewise, hiit does this as well, except it doesn’t make you as much stronger as powerlifting does. Training for half marathons or 5ks is stupid; if you are strong (like a decent powerlifter) and have a low body fat percentage (you can get this from diet) you can do one of these easily at a moment’s notice. I have before. There’s no reason to screw up your health so you can do it.

      Trevor wrote on September 18th, 2013
  6. By all means keep jogging, if you want to be skinny fat. Lift heavy stuff and walk a lot in nature for a few months and see how much better you feel (and look).

    MattyT wrote on July 9th, 2013
    • These two things are not mutually exclusive, you know.

      I don’t think running is going to make anyone fat.

      Jay Gloab wrote on July 9th, 2013
      • “I don’t think running is going to make anyone fat.”

        Actually…it can. The provisio is that you need to be doing serious mileage each week.

        Here’s how it happens, in an over simplified way. Running consumes a tremendous amount of energy in a short time. By the end, muscles have exhausted their stores of glucose and possibly even metbolised themselves for energy because the liver can’t supply glucose in time. The muscles, in need of recharge and rebuilding, stimulate the appetite.

        The hunger that comes is huge – it’s overwhelming because your body thinks you’ve just been chased by a tiger or something. So not only do you feel the urge to eat, you almost always feel the urge to overeat. And because of the nature of the work, you need to eat quite a few carbs to feel half decent again and for the next run.

        If you keep this cycle up, it’s easy to get to slightly overeating all the time just to stay in place, and carbs at that. That will prevent weight loss or even encourage weight gain.

        My friend, whom I promised I won’t mention again, often wanders around with quite the belly and doesn’t really look athletic because she thinks running gives her free reign to eat as much food as she feels hungry for, especially “good” carbs.

        Amy wrote on July 9th, 2013
        • This may be dependent on the distance and intensity. My typical runs are under 30 minutes, and not very hard. I do not find myself to be particularly hungry afterwards, and in fact I do this in the middle of intermittent fasting periods as I’m working on weight loss at the moment, and don’t find myself any more ravenous before lunch.

          So I stand by my earlier statement, slightly amended: Running won’t make you fat, in and of itself. However, over-training *in any kind of exercise* can cause problems. Fair?

          Jay Gloab wrote on July 10th, 2013
        • ^ This is exactly what happened to me in college. Exactly.

          At the end of my 4 years I finally decided I was quitting running (because I hated it) and would only do fun things to stay fit (playing sports, rock climbing, biking, handstands, cartwheels, what-have-you). I shed 30 of the 40 lbs I gained in college without even trying. Largely because my appetite was greatly reduced and I was working jobs that could be described as moving at a slow pace throughout the day.

          drea wrote on July 10th, 2013
        • I am never as hungry after even a long running session as I am after a hard lifting session. I remember the first time I lifted weights about half a year ago, I was ravenously hungry–literally for days my appetite was crazy high. That’s calmed down, but I still get the feeling sometimes from lifting.

          Anyway, it is most likely the crap your friend is eating that’s making her fat rather than running. I run 30-40 miles a week (not too extreme I don’t think), lift 2x per week, and have been gaining strength and not much weight. I eat all I want/can of meat, vegetables, fruit, fat.

          I also question how much plaque buildup referenced in this article was from running and how much was from eating the tons of grains and carbs traditional marathoners consume.

          Mark wrote on February 8th, 2014
      • Hmmm…not to be obnoxiously contrarian, (although that’s in my nature) but I think there are a number of mechanisms that could essentially equate to “running making you fat”. The mechanisms could include:

        – When running causes muscles to atrophy from lack of resistance and the short range of motion involved in most running, (another big problem) you will effectively become like a lot of the people I see on treadmills who are basically skeletons surrounded by blubber, largely due to lack of muscle size and tone. So, did they get fatter? Proportionally yes because even if they “lost fat”, they lost more muscle due to all the running…
        – Mark may have posted it, but there was a study several years ago that suggested that strength training fundamentally changes how the body stores fat such that independent of calories burned, intake etc. , people who predominantly lift will be leaner (which is exactly what I’ve seen and experienced)…so, if running detracts from lifting, then running could be said to make you fat. One could argue that it is selection bias, but the leanest people I see in gyms are almost always spending the majority of their energy lifting not running.
        – As Mark has done a great job of describing, if running causes someone to become very carb-intensive in their diet, this can also lead to a degree of fat retention, especially if one has to cut back on their running for some reason.

        And an (admittedly anecdotal but highly representative, I think) observation… I have been noticing a woman at the gym where I work out who had very nice conditioning when she arrived, and she initially did leg presses and other leg-oriented lifting, although her legs are a little bigger than what some women might consider “ideal” ( I thought she looked great.) She switched over to chronic running however, and every time I see her she looks fatter and fatter, and her legs have lost tone and gained a layer of fat. I have no idea what she eats or anything else about her, but she seems like someone who has a natural tendency to retain fat and going from lifting and running a little, to exclusively running a lot seems like exactly the wrong thing to do if staying lean was her goal…
        So while running may not literally “make you fat”, making it the centerpiece of your training could (and for many people does) have that counter-intuitive result…

        Superchunk wrote on July 9th, 2013
        • “One could argue that it is selection bias, but the leanest people I see in gyms are almost always spending the majority of their energy lifting not running.”

          Are they truly lifters, or actually body builders? If body builders, they’re probably more diet-conscious than the average runner or lifter. As you surely know, muscles (and leanness) are made in the kitchen.

          Paul wrote on September 15th, 2013
    • +1

      Susan wrote on July 9th, 2013
    • If only I could run a little AND lift weights. Boy, that would be nice.

      Alas, it’s impossible to do both and live.

      michael wrote on July 9th, 2013
      • So true, so sad.

        Julie wrote on July 9th, 2013
  7. I’m pretty new to the concept of Primal fitness and would appreciate people’s comments on my general week:

    – Several long walks.
    – 1 game (1.5 hours) of ultimate frisbee or one flow yoga class.
    – 3 crossfit classes (actual exercise less than the hour long class).

    I’m often sore and recovering, but I feel well and getting stronger/fitter. Is this too much exercise? Would it be considered chronic? Too much high intensity? I’m not one of those people that feel like a failure if they don’t puke during crossfit… but I’m still working pretty damn hard.

    Panko wrote on July 9th, 2013
    • I’d say that looks good.

      Metric wrote on July 9th, 2013
    • Why do you pay to go to a class to sweat and get sore?

      Mantonat wrote on July 9th, 2013
      • Mantonat: For me it comes down to motivation. In years past, I’ve tried various self-directed exercise regimes that all quickly fail due to me making excuses. With sceduled classes, I just need to convince myself to show up and the trainers figure everything else out.

        Panko wrote on July 9th, 2013
        • And I probably sounded a little judgmental there. I get it that it’s difficult to find ways to stay fit when modern life isn’t really geared toward it. I did the gym thing for a few years and lost some weight, but I found that it wasn’t sustainable. I hated the regimen of doing the same stuff all the time, the drive to the gym, the smell of stale sweat, jostling for space with other sweaty people, etc.

          It seems like Mark takes every opportunity possible to talk about finding things that you enjoy doing that also involve getting the right kind of exercise (much easier for me in the summer than in the winter). After I quit jogging (it was killing my back) and going to the gym (it was killing my soul), I went off the rails and put on about 20 lbs. But just switching to a mostly primal diet and getting in regular walks combined with some heavy-duty yard work and other household projects, I dropped 15 of that pretty quickly and have been able to maintain it without much effort. My energy level is constant throughout the day and I never get tired unless I miss sleep, for the first time in my life. My goal is to get back to my low weight when I was a gym member, but that will require a little less beer and more of a commitment to some home exercises (planks, squats, push-ups, pull-ups) that I’m a little too sporadic about. I like to go play on the local playground equipment, but I get funny looks from the moms.

          Mantonat wrote on July 9th, 2013
        • Get yourself a pair of Gymnastics rings – you can get a set that can be attached to a variety of things at a cheap price. Then learn the “Muscle up” on rings, and you you can say good bye to needing a gym (just make sure you do weighted squats also, get a barbell for this purpose, or go full primal and use an old rock for weight). A complete workout can be done on the rings or bar, almost anywhere.

          MetalStorm wrote on July 10th, 2013
        • “or go full primal and use an old rock for weight)” –Mantonat

          Thanks to Antiques Roadshow old rocks are now very expensive, can I use a new rock instead?

          Paul wrote on September 15th, 2013
        • ^^^ correction: quote should be attributed to MetalStorm

          Paul wrote on September 15th, 2013
    • I’d say this looks pretty good too. “maybe” drop to just 2 CF classes and do a lighter (maintenance) workout on the 3rd? Just a thought. or sub in a serious mobility class. Sounds like you need it anyway after the UF? I walk 3-4 times a week…about 50 minutes, and do 2-3 CF per week. An occasional soccer game in there too. For me it’s the games that cause the most soreness. :) I’m 45 too.

      craig almaguer wrote on July 9th, 2013
    • Honestly, you can’t really compare YOU to anyone else. I think it’s all about balance: balance in your diet, your exercise, your rest and recovery, and your stress levels. Do you beat yourself up when you miss a CrossFit class? Are you tired all the time? Do you get enough sleep? You have to be constantly asking yourself these questions and be completely honest with your answers.

      I’ve looked into CrossFit on several occasions; I’m a very competitive person and I love lifting, so several people have told me I would love CF. BUT I also played collegiate sports and feel I’ve gotten enough of those workouts that just beat the crap out of me for an hour with someone telling me to keep going, so I’ve decided to not do CrossFit. Instead, I play softball and volleyball, do lots of pushups, lift heavy about once a weak, and bike and go for short runs. I also walk to and from work and walk to our local market every day for lunch. Hourly wise, I’d guess we’re putting in the same amount of work, and I feel good and happy about what I’m doing. I’m not stressed about it, and I don’t feel “bad” if I don’t go for my pseudo-weekly run.

      Anyway, listen to your body. If you enjoy what you’re doing, you’re not stressed out over it, and you’re getting enough rest, then I’d say your doing just fine :)

      Stacie wrote on July 10th, 2013
  8. Now if only I could convince my family. Cardio is the workout shibboleth.

    Braden Talbot wrote on July 9th, 2013
  9. It is funny, that for my entire young adult life I prided myself on how “healthy” I was – biking to the gym each morning to take an hour long spin class. If I didn’t feel like I would drop dead I wasn’t working hard enough. It was a constant battle against fatique – but I was doing the right thing right? Strengthening my heart right? Wow….

    I definatly burnt out of that lifestyle and luckily around the same time that I fell across this website. I’m glad/relieved to know the key is really to easy low intensity cardio often – that suits my life now just fine and I never have an internal struggle to get moving – just happens and feels so natural. Crazy how good it feels just to be doing the right thing for my body. So glad I found this place and subsequently peace for myself.

    Jordan wrote on July 9th, 2013
  10. I agree that chronic cardio is dangerous, but at the same time I really enjoy distance running, so I stick with it because it’s better than no exercise. And I’m not going out and doing marathons every day, the max would be maybe 12 K once a week. I don’t view this as chronic cardio but maybe I’m wrong. I do need to work on the moving slowly frequently part of Primal living! A desk job really does nothing to help that haha.

    Alannah wrote on July 9th, 2013
    • This is basically where I fall. I enjoy running. I don’t intend to ever run a marathon (maybe a half, at most), but I feel like 5k twice a week and a longer run once a week isn’t really overdoing it.

      Also I do high intensity weight training twice a week so my exercise isn’t all cardio.

      Jay Gloab wrote on July 9th, 2013
      • That sounds reasonable, especially if you aren’t trying to run too fast. I think Mark has recommended nothing faster than 10-11 minutes per mile.

        Mantonat wrote on July 9th, 2013
        • Sheesh, that’s barely running. I don’t think I could run slower than that if I tried.

          Jay Gloab wrote on July 9th, 2013
        • Mantonat, pace depends on relative fitness and how often you do it. I am not against a couple of hard runs or rides once in a while. It’s just that doing it every day or 4-5 days a week starts to become antithetical to health.

          Mark Sisson wrote on July 9th, 2013
        • I think that if you are doing something and you are enjoying it then you should keep doing it.
          I have just started training 3X a week for a 5k and I am really enjoying it, and have lost (excess) belly fat. I read articles like these and then I think “am I doing the right thing, but now I just remind myself that I am enjoying what I am doing and it works for me, so I shouldn’t worry”….

          That being said, extreme running/cycling (like every day) or big distances like marathon running, or doing so much cardio that you are addicted or do not have enough energy to put into other parts of your life seems unhealthy and unnecessary.

          Sarah wrote on July 9th, 2013
        • I commute to work by bike once or twice a week (24 miles) and do a longer ride on the weekends of 40 – 50 miles. I used to ride like a bat out of hell thinking it was good for me. Since reading comments on the boards, I’ve begun to understand the wisdom of slowing down a bit. I believe trying to crank up the speed in my riding was increasing my cortisol level with the end result of no real weight loss. I enjoy my rides more now and I’ve actually lost a couple of pounds…win, win

          Pat wrote on December 4th, 2015
  11. Before I came across MDA, I lost the bulk of my excessive weight via running. It turned into a second full time job, running at least every other day and as the mileage increased it became even more time consuming. I still run 4 or 5 local 10K events supporting a local charity or group, but I don’t run near the mileage that I used too. More importantly, I don’t feel like I need to run that kind of mileage anymore.

    Bryan wrote on July 9th, 2013
    • It’s interesting because for me too I found that my weight comes off faster with running than it does with anything else… Bjj and crossfit and weight training included!

      Bjjcaveman wrote on July 9th, 2013
      • Just thinking out loud, but I’m wondering if you lost any muscle through all the running? I run about once a week and also bike quite a bit, but what I’ve enjoyed about the PB is how strong I am feeling again. I haven’t seen a ton of movement on the scale, but I can see a definite change in body comp and strength gains, which leads me to believe that I am losing fat and gaining muscle, so at least my measly five pounds of weight loss is mostly (if not all) fat.

        Again, I think this all comes to balance. It seems Bryan got consumed with running, and it became a stressor in his life. If something, even exercise, becomes stressful and something that becomes consuming, I don’t think we should be doing it. :) Having said that, I’ve always enjoyed lifting more than cardio, so I might be a bit biased!

        Stacie wrote on July 10th, 2013
        • I became obsessed with ‘getting’ healthy and incorrectly assumed that running was the only way to do it. I don’t think I was losing muscle as I was running hills and steep terrain and getting faster. However, on my ‘off’ days I would I would allow myself to step away from my otherwise okay diet. Beer, cheese (Wisconsinite here), etc… After reading MDA, it’s the classic ‘what not to do’, I was at a point of treading water. Disappointed with not being able to lose that little bit around my core via running, I did a round of P90X Lean (without changing my diet). My body changed some and I felt strong. It was still a little disappointing that I wasn’t able to lose that extra bit of fat yet. It was stressful Stacie, I was busting my ass and not seeing the results that I wanted/expected.

          Enter Mark Sisson and MDA!

          I still run about once every two weeks, but I stop when I feel like I’m done and don’t push for all that extra mileage. Now between 3 and 6 miles is about as far as I go.

          Cheers all!!!

          Bryan wrote on July 11th, 2013
  12. What about the competitive athlete who is less “chronic?” This entry seems pointed to the non-stop athlete who doesn’t train smart and allow for proper – if any – recovery time. I’m a competitive cyclist who trains 6 to 8 hours a week and varies the weekly training pace with some hard days, endurance/moderate pace days, and easy recovery pace days. I even have a couple off days a week because that’s just life and having other responsibilities. I’ve been on a paleo/primal diet approach for about 3 months and am seeing my best form ever on the bike.

    Is there any research out there comparing the “mindlessly going non-stop” guy to the those who go in with a much more thoughtful and balanced training plan (and have not been eating the standard American diet)?

    Speedy wrote on July 9th, 2013
    • I don’t have any research at alll, but I do have a free opinion (the best kind). 😉

      Do you actually enjoy that much training? Will you become pro? What does biking in general mean to you? Could you stop and pick up another form of exercise if you became injured? Could you get on your bike and simply enjoy the ride and the sunshine?

      If you’re not having fun (the *only* point is the competition), then it’s not something that encourages health. Cardio can be a very addictive activity (runner’s high anyone?). I know people who have sworn up and down how thoughtful they are – different from that “clearly crazy guy training over there”, but at the end of the day, an addiction is still an addiction.

      Ultimately only you know what biking means to you and how healthy you actually are.

      Amy wrote on July 9th, 2013
      • Took the words right outta me mouth…

        Nocona wrote on July 9th, 2013
      • +1

        Along these same lines, has anyone read through Paleo for Athletes? I saw it at a sports clothing store and thought about buying it since I’m still fairly active and just love competition and sports, but then put it back because I didn’t think it would tell me anything that the PB hasn’t already.

        Stacie wrote on July 10th, 2013
      • Well said. Combining a competitive personality with an addictive activity is a recipe for overworking.

        BillP wrote on July 10th, 2013
      • Of couse I enjoy riding my bike and competing, otherwise, why would I train? You don’t have to be a pro (and I never will be) to pursue a sport with a desire to achieve and improve.

        I prefer to call it a passion since it is my conscious choice (addiction is not a choice) and am well aware that competitive endurance is not the optimal path to health. Quite frankly though, I don’t care because it’s something I love to do. What I do care about is doing the best I can to mitigate the inflammation/damage and optimize my recovery and performance, which by default aids in long-term health. Hence my reasons for going full bore into a primal/paleo diet recently.

        Which brings me back to my original question about this study. Were the long term diets of the marathoners scrutinized at all? I’m not out there hammering on the bike everyday. As Mark stated “It’s the chronic, day-in, day-out long, hard stuff that is counter-productive.” Is there a happy medium anywhere in between?

        Speedy wrote on July 11th, 2013
        • I had similar questions about the marathoners. They’re traditionally a high-grain, high-carb consuming bunch, both in the long-term and binging before races, which sounds like a more reasonable explanation of atherosclerosis to me than running.

          Of course, when you define a group as runners instead of high-carb dieters, it is most likely the running and not the high-carb dieting that will get the blame for any health ills.

          Mark wrote on February 8th, 2014
  13. I’m on board, but this is not an easy philisophy for a 44 year old to accept. But it’s working, and I like it!

    Greg wrote on July 9th, 2013
  14. I’m 62 and have run marathons and half marathons for quite a while. Now wisdom, injury, laziness and a little MDA have brought common sense into my life and I have wound that activity down. I still do one race a year, the Air Force Half, just since I’ve done about 20 in a row and want to do another 20. But I found Senior Olympics as well and now do 100, 200, 400, 800 and 1500 meter track and field. Times pretty much suck, but I am in the game. Doing intervals and twice a week weights is really fun. Doing my weekly 90 minute to 2 hour grinder run is also fun again since I don’t have a lot of miles competing for my precious muscle cells.

    Bottom line: Intervals and weights AND a little mid-distance cardio are all part of a good fitness program. Being fat adapted, using coconut oil as a supplement daily, and now, trying out superstarch, all seem to be the optimum path to sane fitness and most of all, keeping it fun!

    I can also still walk/play 18 holes and carry my bag and not be overly tired at the end. A non-trivial feat in Virginia summers. -JD

    John D wrote on July 9th, 2013
  15. I wish “sprinting” would get as hip and trendy as distance running does. Theirs no better feeling than when you get into that peak acceleration in my opinion…

    The problem is, you can’t exactly “spend an afternoon” doing it.

    Anyone want to start a sprint club in ATX?

    Kevin wrote on July 9th, 2013
    • “hip and trendy” – you hit the nail on the head with that statement. Need proof? Just take a drive around town and start counting all the “26.2” and “13.1” stickers.

      My personal favorite is the 0.0 sticker 😉

      Sean wrote on July 9th, 2013
      • I never knew what those stickers meant. I’m definitely not a marathoner! I don’t even like to ride 26.2 miles in the car.

        The Beckster wrote on July 9th, 2013
      • “My personal favorite is the 0.0 sticker”
        Hah! If I ever see one of those I will totally buy it.

        Maybe you should start selling .1111 stickers.

        Lea wrote on July 9th, 2013
        • ok, guess I’m dumb – I don’t get the “.1111” comment….

          John wrote on July 9th, 2013
    • +1

      Amy wrote on July 9th, 2013
      • +.1111

        Nocona wrote on July 9th, 2013
  16. I have a related question– lately I’ve been doing a lot of heavy work in the garden (digging, forking, mattocking clay soil, laying pavers, uprooting small saplings) for multiple hours a day. I stop to catch my breath between exertions, but I’m definitely pushing my endurance levels (I’m a middle-aged woman) & I began to wonder if I might be overdoing it. Mind you, I feel great (1000 times better than days when I don’t get outside), but I adore gardening so much, & I used to be a running addict, so I can’t entirely trust my instincts! Does the variety of movements, stopping to recover, & so on, make up for the long-term pushing?
    I really want to believe that I’m doing my body good– I KNOW it’s good for my head!– but I’ve fooled myself before– any thoughts?

    Paleo-curious wrote on July 9th, 2013
    • paleo curious-
      I am only 10 months primal, but was also a former runner turned gardener. I’m sure gardening is excellent exercise but I would definitely listen to your body to know when to stop. I have an autoimmune condition so if I overdo it outside it gets ugly– surely transplanting that large shrub could wait till tomorrow? I’m getting stronger every month because I’m careful not to push it and at 43 years old I’ve NEVER felt this good.

      Stephanie wrote on July 9th, 2013
      • Thanks Stephanie! Nice to know a fellow convert. :-)

        When you say “listen to your body,” how quickly do you get feedback? I surely know to look out for back pain or extreme exhaustion, but how can you tell if you’re just pushing a bit too hard, too often?

        Paleo-curious wrote on July 9th, 2013
        • What do you feel like the next day? If you feel good, you did it right. If someone ran you over with a truck in the middle of the night, you might have pushed too hard yesterday. 😉

          Just rest when it happens and you’ll be good to go. The goal is to feel good 80% of the time.

          Amy wrote on July 9th, 2013
        • Or least, my goal is to feel good 80%-90% of the time. I’m not sure that’s universal. 😉

          Amy wrote on July 9th, 2013
        • If that’s the criterion, I’m doing fine– I honestly feel better (& sleep *much* better) after hard garden days than when I’m stuck at the drawing table all day. But I would have said that about a hard run too until I ran my knees to bits… :-/ I was mainly carb-fueled then though, if that makes a difference.

          I’m a jitterbug by nature who somehow ended up in a line of work that is super-sedentary– I have to stay extremely still to paint the way I do– so when I have the chance, heavy gardening for hours feels absolutely wonderful! I just hope it’s as good for me as it feels.

          Paleo-curious wrote on July 9th, 2013
  17. I started early January this year with MDA and shortly after found a local conditioning gym. My best weeks are a mix of gym, walking or cycling all for about 1 hour each for an average of 3 hours, for the week!

    I have lost 58lb to date.

    I am comfortable with this volume of workouts as it still allows for the rest of my life to continue as normal

    Gordon wrote on July 9th, 2013
  18. Thank you! This is perfect to show my family members. I have lost 70 lbs eating primal but I still have 50 to go. When I told my cousin I was going to be focusing on weight lifting this fall, maybe some o-lifting (she asked), she repeatedly and assertively told me that that it was too “static” and I needed to do some running. Static? Ha! Ever do a power clean? No, of course you haven’t. But her reaction is typical. Add the armchair exercise advisors to the red-meat-will-kill-you crowd. And don’t pay any attention to my chronic foot and ankle pain resulting from my days as a college athlete in the 90s trying to lose weight by pounding the pavement every day.

    Louise wrote on July 9th, 2013
  19. Two – 25 minute body weight workouts and one 20 minute sprint session along with a few leisurely walks a week and I’m in better shape than when I was 25. That’s coming from a jock in their 50’s now! Call me a believer.

    Nocona wrote on July 9th, 2013
  20. Hey Mark, I am curious about what the line is for “chronic cardio”. I understand why you might not want to do it, but I am not sure where the line is for too much and just right. I am fairly out of shape as it is and have been trying to walk an hour or two very slooow hours a day on a treadmill. Reason for the treadmill is that it has a padded deck and I have questionable knees. I figured this approach would help harden the legs up a bit and help prevent injury instead of going too hard and hurting myself. This this too long though? I need to loose some weight and don’t want to make it harder on myself by setting myself up for failure.

    Courtney wrote on July 9th, 2013
    • Courtney, slow walking on a treadmill is not in the realm of chronic cardio. Go for it.

      Mark Sisson wrote on July 9th, 2013
      • Thanks :-)

        Courtney wrote on July 11th, 2013
  21. I just got out of high school where I ran cross country and track and while I was never the fastest, I was miles ahead of my buddies that ran extra miles after practice or 20+ miles over the weekend. It was a rule that I ran slowly in practice and did no weekend running and almost always beat the guys that did. The only time I didn’t win was against a genetic freak who could run three times as much as the rest of us and keep going like he hasn’t done a thing. I don’t think there’s anything wrong with doing consistent longer runs as long as you keep up with everything else that makes us who we are. I know people that strength train to excess and are worse off for it and I know people who run to excess and are worse off for it, but I do know people who do both consistently that are much healthier, leaner and like me in high school better off than the everyday hypermilers I’ve come across.

    Dalton K. wrote on July 9th, 2013
  22. Agree, this topic deserves more attention. Recently had my RQ, cals, anaerobic threshold and VO2 measured at gym. Showed that at HR of 144-154, I burn 80% fat on my primal diet. Learned that my jogs were too fast. Keeping HR at or below 150 leaves me feeling better after a run than before. Mark, is a long (3-5 mi) slow “run” 3-4 times a week chronic cardio?

    Tom wrote on July 9th, 2013
    • Tom, probably not at that HR and distance.

      Mark Sisson wrote on July 9th, 2013
      • Mark, thanks for your reply. New to MDA, PB. 3 mo ago, went primal. Have lost 15 lbs. feel great.
        As a gastroenterologist, I noticed some of my Crohns patients go into remission after eliminating grains.
        I’m sold on it.
        Sure you thought about being a doctor. You’re helping more people doing what you’ve done the last 20 yrs.
        Tom McGinn MD
        Omaha NE

        Tom wrote on July 9th, 2013
  23. Thanks so much for writing this. It really couldn’t have come at a better time for me. I used to do Ironman Triathlons, marathons, etc – if it was long and slow, I did it. I thought I was in the best shape of my life when I did these. I since have had 2 kids and have fallen off the exercise bandwagon but keep saying that I need to get back. However, I found out in December that I have a genetic heart condition where my aortic tissue is weak, leading to it being enlarged. While it is not yet an aneurysm, it could potentially get there. My cardiologist has recommended I do a moderate amount of slow, easy cardio – swimming, biking, running, rowing with VERY light weights along with going on a beta-blocker. All of this is making my entire world as I see it turn around and I am having a rough time dealing with all of this. However, reading articles like yours make me feel better as I know my new goal should never be what I used to do, heart defect or not. What my doctor is prescribing (except for the beta-blockers part, still really need to come to terms with that) sounds like it is in line with what you are recommending as well. So thank you for this – at least I feel like my “alternative/Paleo” life is agreeing with the established medical community for once!

    Michele wrote on July 9th, 2013
    • You may want to get a second opinion on the beta-blocker, even if you love your Doc. Have someone really explain the drugs, their side effects, and any possible alternatives. If you end up needing to go there with drugs, (we just had a bought with modern medicine involving our infant daughter), you’ll feel a whole lot better about it and much more involved.

      Amy wrote on July 9th, 2013
      • Thanks Amy. I don’t actually love my doctor, and definitely plan on getting a 2nd opinion. I got a several month reprieve because I am still breastfeeding my son (he’s 11.5 months) but she wants me to go on the beta-blockers as soon as I am done. But when she explained that she also was trying to convince me that I should stop breastfeeding as there really was no point to do so after the baby is 12 months old and that really turned me off. She obviously has only one path in mind (drugs) and that path has no alternatives. Time for a fresh opinion in my mind.

        Michele wrote on July 9th, 2013
        • Ugh. I’m sorry – that is a turn off. My 18 month old daughter would disagree that there’s no point to nursing beyond 12 months. :( (We’ve consistently weaned at 2, not 1).

          Anyway, it’s hard to find good Docs, but it’s sooo worth the time and effort to find one. We went through a few Docs before we ultimately agreed with the original opinion and went ahead with surgery for our daughter. IMO, we ended up with a better overall experience and more importantly, a better surgeon for our child.

          Amy wrote on July 9th, 2013
        • If you need a rebuttal for the breastfeeding: childrens adaptive immune system isn’t completely up and running until they are three. Until that time, they benefit from the antibodies they get through breastfeeding. And because mommies tend to get in contact with whatever the baby encounters, pathogen-wise, they tend to produce exactly the antibodies the little one needs. Kinda brilliant, really.

          In your case the question is if the benefit of ‘prolonged’ breastfeeding for your kid outweighs the benefit you could have from the meds. There may be a lot wrong with the medical establishment, meds can still save lives and/or greatly improve the quality of it. I can’t tell you what to do in this case, but I’d definately get a second opinion if this will help to get a better view of your options and the pro’s and cons, to make an informed decision.

          Feather wrote on July 10th, 2013
  24. Re: endurance athletes and atherosclerosis

    I love Dr. Stephanie Seneff’s theory that atherosclerosis indicates a cholesterol deficiency. She argues that if the body’s default state is to heal, why would it put plaque so close to the heart? Maybe as a local storage site for cholesterol.

    Anyway, this theory jives with some research on the “cholesterol lowering” effect of intense exercise. Food for thought.

    Meredith wrote on July 9th, 2013
  25. Hey Mark,
    I just finished the book “Born to Run”. I’m sure you’ve read it, or heard of Barefoot Ted, or seen these tribes in the world that thrive on running ultra distances?? Help me out here… is it the technique? the story is so convincing that running HUGE distances is how we evolved, basically saying Grok himself was an ancient ultra runner!

    Christy wrote on July 9th, 2013
    • Christy,

      Not sure if you heard, but in an unfortunate turn of events, Caballo Blanco (Micah True) died of heart issues on a run some time in 2012. Of course one data point does not a theory confirm, but there is a lot of science backing up what Mark is saying whereas there isn’t a lot of science claiming the HUGE distances are healthy.

      Peter wrote on July 9th, 2013
    • Christy, we did evolve to be able to run upright, I agree. But we didn’t evolve to frequently run long distances at a high heart rate. Other than the Tarahumara, who are unique in the world really, no other “tribes” run very much. H-Gs have the ability to do persistence hunting once every few days (mostly as a result of always being Primally fit across a spectrum of ftness metrics), and if you’ve seen the videos, those guys aren’t running very fast at all. They are mostly jogging, resting, sprinting, cutting the tangent and using tracking skills. Then they usually rest for days after the kill.

      Ted is a great friend and teaches “persistence running” at our PrimalCon events each year. He is also quite against chronic cardio.

      Mark Sisson wrote on July 9th, 2013
    • Someday I think I should write “Born to Walk A Whole Lot and Sprint Occasionally” and see if I can make it best seller. Me thinks it would probably flop. 😉

      Amy wrote on July 9th, 2013
    • @ Christy: Check out a book called ‘The Old Way: The Story of the First People’. The author (and her parents) spent years with the Bushmen of the Kalahari (African Savannah – where modern humans evolved into modern human). The “runners” were few and far between. They stalked prey. They didn’t run after it at a steady pace for hours on end. Prey doesn’t run from predators like that either. And – even if we were “born to run” due to hunting down animals that can’t apply to the female of the species because we weren’t part of the hunting group. They would walk 12 miles or more in a day carrying more than double their body weight (includes an offspring or two) as they “gathered”. The men were the hunters the women were the gatherers and the gathering is what provided the majority of the food for the band. No we were not “born to run”. The human body is designed for movement. We were born to move.

      Heather wrote on July 10th, 2013
  26. I did a few long distance hikes (3 months of daily marathon-length hiking in the wilderness with a pack on.) The result was not good. I lost muscle, I screwed up my metabolism royally, I intuitively felt that this was not healthy even though I loved knowing I could walk 30 miles in a day like some kind of super-woman and even though being out in nature like that is wonderful.

    Now I follow the Primal Blueprint Fitness recommendations: 1x/week sprint, 2-3x/week lifting, daily slow walking, one hike a week as my “play”. My body is stronger, healthier and better looking than it has ever been. I’m 48 years old and have never felt as young and healthy in my entire life.

    I wish you would write about your fitness program more, Mark. It has been a revelation and miracle for me. The diet is only half the story. The fitness program sealed it all in for me.

    Diane wrote on July 9th, 2013
  27. I’m not sure exactly where I stand on chronic cardio due to the fact that when I lost most of my baby weight I was a chronic cardio-er (minimum hour a day runner). I lost the final lb’s switching over to a Primal way of eating however and have since maintained my lowest weight ever (with a 5 lb window), and kept my body fat percentage at 16/17 percent (41 year old mom of three). I lift weights a few times a week, throw in some yoga and do sprints maybe once a week. So… there are my two cents.

    kate wrote on July 9th, 2013
  28. Well Mark, I’ve resisted your efforts to get me to exercise for the past year and a half. Your new book probably will finally get me off my duff!

    Siobhan wrote on July 9th, 2013
  29. Several years ago I ran a few marathons & did some longer triathlons, culminating in an Ironman. Looking back, I can’t say the training was enjoyable, but there was a great sense of satisfaction that I could set a goal, figure out what I needed to do, and then meet that goal. The human body is amazing in its adaptability. Recently I gave birth to my first child (more amazement at the human body) and am pregnant with my second. I’ve found that going for a few walks/hikes, strength training a few times/week, doing some yoga, and sprinting 1x/week (when not pregnant) has left me feeling great, although less aerobically conditioned than before. With all of the science out there, I agree that Primal Blueprint fitness is the optimal prescription for overall health, and it feels very natural & sustainable.

    However, my question would be: what types of activities are best for goal-setting? The occasional 5k or sprint triathlon? Climbing a challenging mountain? The occasional endurance event? While I don’t want to return to training almost exclusively for endurance events, I do see myself looking to set & achieve physical goals from time to time, especially once the kids get older. I would love any suggestions for this.

    Megan wrote on July 9th, 2013
  30. I’m trying to think of this in terms I can relate to. Is someone who does an aerobics class three days a week potentially damaging their heart, or is this limited to “ultra” and “endurance” athletes?

    Alice wrote on July 9th, 2013
    • Alice, don’t overthink this. If you can do it 3x week and recover easily, then it’s not in the realm of chronic.

      Mark Sisson wrote on July 9th, 2013
  31. I do not do cardio anymore. Not regularly at least.

    Long walks and upstairs sprints, together with weightlifting circuits seem to keep my heart well trained without the boring and repetitive running sessions. So well trained that, every 5-6 months, I decide out of the blue to do a nice long run on the treadmill at a sustained pace. Guess what? It seems I am just as fit as I was when I was running 4 times per week.

    No pain no gain? I would say: painless gain! How can you not love this?

    Primal_Alex wrote on July 9th, 2013
  32. As my wife goes out to train for yet another triathlon, i tell her I am going to sprint down to the mailbox (200 yards) and back for my work out today.. Just after i finish cooking my bacon.

    MadMav wrote on July 9th, 2013
  33. I prefer walking – I walk 3 times a week, about 4 miles each. I live in the foothills of Northern CA and the route I take has considerable up and down-hill slopes,so it turns into a really good workout.. I don’t know if I could even run anymore. I have a touch of COPD so the walking is strenuous enough for me. I lost 40 lbs doing this as well as eating Paleo. Now I’ve added a weighted backpack to the routine to add intensity. Works for me.

    GaryB444 wrote on July 9th, 2013
  34. Hello :) as a former jazz aerobics instructor from the 80’s I completely understand all the detriments of chronic cardio…. I am wondering if I could get some thoughts about my current situation. I live in the deserts of Southern California and while during the cooler seasons I can always get in those long “low and slow” walks and hikes, I’m not sure what to do in the summer……90 degrees by 9 am is a standard. I do own an elliptical and this is the most convenient thing to do. What might you suggest? Elliptical for an hour super slow a few times per week, no intervals for example?…..all suggestions welcome, thank you :-)

    Julia wrote on July 9th, 2013
  35. Food for thought to the marathoners: I had Jeff Galloway’s Book on Running. From what I recall Jeff talks about doing a seminar for marathon training. Jeff writes about a guy who asked if Jeff thought it were possible to only run once per week and not hit the 20 mile wall. Jeff said he didn’t think it was possible. But that’s how this guy was training; he was only running on the weekend. This guy only had time to put in one long distance run each week. Back then I had friends who thought they needed to run every day. I liked lifting weights too, and my argument to them was if you don’t lift every day I didn’t think you should run every day either. This once per week runner got me thinking about just how minimum volume a person could do and still get in the best shape of their life. When I was 47 years old I cut back to lifting only once a week per body part (3 workouts per week) and got my bench press up to 365lbs. Here I was through my earlier years (esp. 20s and 30s) trying to get my bench over 300. At 47 I was warming up with 300lbs and wondering why I had beat myself up so much (getting periodically over trained) from lifting too often.

    Scott wrote on July 9th, 2013
  36. Completely agree. When I run I know I’m not doing it properly. My knees ache as do my hips and feet. I’ve always hated it and knew something was wrong. Now I know why, haha! I walk a lot at work (big warehouse) but have just started adding an extra one in the evening. Felt great. BTW have lost 3 kg in 3 weeks going primal. Wasn’t a fatty to start with but was starting to soften at the belly. Now much leaner at 81kg. Am at 12% body fat. Wanna dip below 10. Cheers! This is a great website! Bought the book!

    Carey wrote on July 9th, 2013
  37. Has anyone read anything on endurance training and hypothyroidism? I’m a 40 year old male, in shape and healthy. Spent much of my 30s doing distance running and hardcore marathoning/racing to almost one marathon a year combined with many other races. Gradually my TSH levels increased to the point where the doc put me on meds.

    I HATE having to take a pill everyday (I don’t feel this way about supplements) and I can’t think that all the hardcore training had something to do with this.


    Patrick Hansen wrote on July 9th, 2013
  38. I’m a believer too. As a sugar burner marathoner I was 174 lbs at 18% body fat. Began primal blueprint this year and now 167 lbs at 12% body fat. Before I felt beat up all the time now I have energy to spare. I’ll never go back.

    Derek H. wrote on July 9th, 2013
  39. Patrick,I also did marathons in my 30s and my TSH levels say I have hypothyroidism. I’m 42 now I feel great the large majority of the time, exercise primally now and refuse to take medication. Don’t let the number on a test dictate how you feel. I came to realize the days after a meal with gluten is when I feel sluggish so I cut out gluten all together. Simple but not easy.

    Derek H. wrote on July 9th, 2013

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