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Let me introduce myself. My name is Mark Sisson. I’m 63 years young. I live and work in Malibu, California. In a past life I was a professional marathoner and triathlete. Now my life goal is to help 100 million people get healthy. I started this blog in 2006 to empower people to take full responsibility for their own health and enjoyment of life by investigating, discussing, and critically rethinking everything we’ve assumed to be true about health and wellness...

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April 28, 2014

Dear Mark: Leg Fatigue, Too Much Muscle Meat, Starch Persorption, and Hadza Study Author Responds

By Mark Sisson
43 Comments

Road CyclingFor today’s edition of Dear Mark, we’ve got four questions. First is a question from a reader who exemplifies the “between a rock and a hard place” situation inherent to chronic cardio. Second, I address a reader who worries that I’m not worried enough about exclusive muscle meat consumption. Third, I give my thoughts on whether starch persorption into the blood stream is a real problem for most people and a black mark against resistant starch. And finally, one of the lead authors of the fascinating Hadza gut biome study mentioned in a recent Weekend Link Love clarifies the precision of their sample preservation methods.

Let’s go:

Mark,

After years of aggressive road cycling, the lone aspect I am struggling with since starting the Primal Blueprint last year is leg fatigue. Granted I am 55, but a very healthy, lean and active 55. I find through repeatable experimentation that heading out on the bike on the normal daily Primal menu results in leg fatigue, but if I carb up the night before and again 2-3 hours before the event, I am just fine, back to my old self. This is how I did it before Primal. Am I missing something? By the way, though, when I do carb up, the muscle inflammation spikes up too, dang it!

Didn’t you mention that you were writing a book on Primal for endurance athletics?

Thanks,

David

You’ve just stumbled onto the big problem with chronic cardio. In order to stay competitive, maintain the training, and perform like usual during your rides, you need to carb up – usually with the junkiest stuff you can get your paws on. Short term, it feels good. You kill the ride, you improve your time, all is right in the world.

But if you carb up enough to support your massive training load, you may end up suffering from systemic inflammation from all the training and all the sugar. Long term, your body suffers and starts to fall apart at the seams. You’re noticing that yourself.

If you ask me, this is simply more evidence that “aggressive road cycling” isn’t something we should be doing on a regular basis; at least not if your goal is optimal health. To do so requires a suboptimal, inflammatory diet that’s almost as difficult to maintain as the training.

Also, when you go low-carb and start fat and keto-burning, you lose your top end for a while. There may be a lengthy adaptation that’s even lengthier if you’re not strict about it. Carbing up, particularly with non-Primal sources, may extend the adaptation period. If you’re not already, definitely start lifting heavy once a week in the gym, focusing primarily on the lower body. Squats, deadlifts, leg presses, lunges – that sort of thing. Doing heavy maximum output leg training in the gym once a week may help with adaptation and can actually increase the resistance of your muscles to fatigue during training.

There are ways to “carb” up the night before planned hard workouts (and you shouldn’t make every workout hard – maybe just twice a week) that minimize inflammation and maximize usable glycogen. Note the term “usable” that means that you might not need more than 150 grams total to top off muscle glycogen stores, especially since you’re only going to be drawing on (and depleting) leg glycogen on the bike. Fruits are a good way to do that, as are tubers.

Ideally, you just limit this kind of training. At any age but especially yours (and mine), that aggressive riding is hard to maintain and still thrive. Hard long rides for fun? Sure, I might even go for those once a year or so. If you insist (and I know you will because I know the feeling!), there is a better way to do this kind of training, which I’ll be exploring in my upcoming book, Primal Endurance. It’ll be right up your alley.

Dear Mark,

I know you’ve talked a great deal about what we lose out on when we shy away from the fattier cuts. However, I’ve never heard you say anything about the possible hazards of eating too much muscle meat. I think people read about how hunter-gatherers ate so much animal and think “Oh, well I can eat 2 pounds of steak every night” but hunter gatherers would never have eaten that much muscle meat at a time. Is it possible that a lot of the red flags about meat consumption are true and just misunderstood? Is it unhealthy to eat so much meat and so little of the fatty organs?

Dylan

I completely agree. The only point I contest: I have addressed this in previous posts.

I’ve come up with methods to trick oneself into eating organ meat because I recognize the nutritional importance of eating them.

I even took readers on a visual tour across the edible landscape of an entire animal carcass.

When I analyzed the latest “meat will kill you” study, I wondered if some of the (tenuous and often insubstantial when you correct for unhealthy lifestyles, cooking temperature/method, processed meat intake, etc.) connections between meat intake and early mortality can be explained by our widespread tendency to only consume muscle meat and eschew organs, bones, skin, and gelatinous cuts.

I don’t know that it’s “unhealthy,” but I do think that if you intend to base your diet around animal products, you can’t expect to get the best – or even good – results avoiding 75% of the animal. From Paleolithic hunter-gatherers eating the still pulsating colon packed with fermenting vegetation to grandmothers who’d visit their favorite butcher every Tuesday for bones, oxtails, liver, and shanks, our ancestors both distant and near ate everything. That’s been the normal way to “eat meat” up until a generation or two ago, and I suspect there’s something to it.

Hi Mark,

I’ve been following your posts about resistant starch and my husband and I have both started taking potato starch in the last couple of days.

Then I read this today from a podcast by Ray Peat:

‘Adding butter or cream slows the digestion so it isn’t such a powerful insulin stimulant, but it also reduces the chance of what’s called persorption of starch granules. […] A potato starch granule happens to be very big. Other starches are more the size of a red blood cell, but a potato starch granule is several times fatter than that. But even these huge granules bigger than cells can get squeezed right through the wall of the intestine, enter the lymphatics and the blood system, so within 30 minutes after you eat starch without fat, you see the starch grains circulating through your blood, and if they’re big they’ll plug up your arterioles. Studies in mice showed that a high raw starch diet accelerated their aging. You can demonstrate areas of every organ that were being killed by plugging up the arteries.’

It freaked me out a bit and I’m wondering if this is true. I’ve always found your posts to be well researched and I trust your opinion. Is this something we should be concerned about?

Thanks,

Mel

I like reading Ray Peat’s stuff, you know, I really do, but I think he fixates on the minutiae way too much, often using obscure animal research and extreme conditions to support his positions.

Persorption of starch occurs, but it’s totally normal. It happens with any starch, not just raw starch, and humans clear any persorbed starch from the blood within a couple hours. In infants, it’s probably a feature rather than a flaw: human milk oligosaccharides, normally valued only for their prebiotic qualities, get into the bloodstream to mop up and clear pathogens while the immune system is still in its, ahem, infancy.

Persorption may be increased in cases of leaky gut, but what’s ironic (if you take the view that persorption is evil) is that the butyrate produced as a result of consuming resistant starch and other prebiotics lowers intestinal permeability. So if anything, eating more raw potato starch will reduce problematic amounts of persorption.

This is where taking a step back from the minutiae to look at the big, evolutionary picture can help. We can argue about how much starch humans have historically eaten, but everyone agrees that we have eaten starch for tens of thousands of years. Some cultures have eaten more than others. Many seemingly healthy cultures eat a fair amount of starch. There are problems with starch (over)consumption, especially in the modern sedentary inflamed population, but I don’t think persorption of starch granules into the bloodstream is one of the major ones.

In the end, you have to weigh your options. Do you continue taking potato starch for the direct, observed, experienced, empirical benefits to digestion, sleep, gut health, and metabolism? Or do you hang your hat on a theoretical problem, on the off-chance that persorption of starch into the bloodstream is slowly, inexorably, silently killing you? I know what I’d choose.

Dear Mark,

First, I’ve been a long time reader of your site, have met you in person, and greatly admire the effort you put in to educating the community about how to achieve personal health and wellness. In the last couple of years, I’ve only managed time to read the link love days, which are very useful for me to see what kind of news aggregates on your radar. This week I am honored that one of those news pieces you linked is to the study that I and my colleagues recently published on the Hadza gut microbiome. Thank you for promoting further interest in this field of research and in our work.

I wanted to say, though, that while I support healthy discourse in science and think it is fair to offer the conclusions with the criticisms, in our case I am concerned about the emphasis on the criticism by Rob Knight that our results may be not valid due to the ethanol/silica storage procedure, and that the soon to be media zeitgeist on our work may be ultimately dismissive of our contribution. And this because of a comment wrought out of conflicting interests (Rob Knight works with Jeff Leach on their own Hadza microbiome study). Instead, I would like to encourage anyone with criticisms to read our methods in which we of course took measures to ensure this protocol would not invalidate our results. We first validated the method by sequencing and amplifying test samples both frozen and dried (ethanol) and obtained comparable results.

So, I suppose what I am saying is that while criticisms are welcome and a natural process of science, it is not helpful and instead harmful to give platform to unfounded criticisms that have already been thoroughly addressed in our original methodology and reporting. The paper is completely open access and I welcome any and all people to read it for themselves!

Gut microbiome of the Hadza hunter-gatherers

All the best,

Stephanie

I appreciate the email. From what I can tell from reading your methods and your explanation of the issue, you took all necessary precautions to ensure the validity of your results was not compromised. It seems that the Hadza do indeed throw into disarray our previously conceived notions of what constitutes a universally healthy gut biome.

Great work, Stephanie, and thanks for bringing that to our attention. Please do it again whenever something seems amiss!

Thanks for reading, everyone. Be sure to keep the questions coming and I’ll do my best to answer them.

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43 Comments on "Dear Mark: Leg Fatigue, Too Much Muscle Meat, Starch Persorption, and Hadza Study Author Responds"

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Tyrannocaster
Tyrannocaster
2 years 4 months ago

That link at the end of Stephanie’s comment leads back to this page, not to her study.

NOLA Paleo (new orleans)
2 years 4 months ago

I’m finding potato starch so interesting. It hasn’t helped with sleep yet but I’m still hopeful. I did have some grocery store sushi a few days ago and took my blood sugar readings. I was amazed that I didn’t really get any spike. I still find it hard to wrap my head around though.

2Rae
2Rae
2 years 4 months ago
I agree with you Tamara, I bought some, took some, eat sushi here and there and try to figure out if there is much of a change in sleep, digestion, “body music” etc. So far the best sleep is when I have my homemade potato salad just before bed. I make it with Bubbie’s pickles so there’s a bit of probiotic in there too. However, that may have just been a good night for me….. who knows. I do note there is a LOT more “body music” with the potato starch than there is with the real food RS. I… Read more »
Diane
Diane
2 years 4 months ago

“I think he fixates on the minutiae way too much”

I find this to be true of a lot of nutrition stuff. Too many people try to use logic to make health decisions, extrapolating the science with their own linear thinking process. If a little bit does this then it’s a catastrophe! Rather than seeing that the body is a system of balancing processes that step in to protect you from going too far in this or that direction. That’s why I like your basic primal blueprint. It’s so lacking in the minutiae and is simple. Simple works pretty darn well.

meepster
meepster
2 years 4 months ago

Yeah, same here – and I am glad that Mark is addressing that. The Forums are especially full of this kind of obsessing over minutiae. The way I interpret the Primal blueprint is “eat real food, get good sleep, move around, lift heavy, get some sunshine, enjoy life, and the minutiae will take care of themselves”.

I don’t think that Grok had a degree in biochemistry.

Nocona
Nocona
2 years 4 months ago

Agreed. Also look at yesterdays Link Love and read about Vitamin J…As in Joy!

Paleo Bon Rurgundy
2 years 4 months ago

Don’t forget to drink your malk for vitamin R.

C L Deards
2 years 4 months ago

You bring up interesting points on chronic endurance. I’ve read elsewhere the dangers of causing chronic inflammation by doing frequent cardio. I think it’s telling that runners come down with heart and lung problems later in life yet running is considered a healthy activity.

One of the more satisfying exercises I’ve done recently was a long hike with the family. By the end of the day we were exhausted, but happy. Made me realize that there is something truly primal to long hikes. I think it keys into something deep in our being.

Wenchypoo
Wenchypoo
2 years 4 months ago

I think it’s telling that runners come down with heart and lung problems later in life yet running is considered a healthy activity.

Like Jim Fixx and Bill Clinton? Jim was found on the side of the road dead, still in his running gear.

Pastor dave Deppisch
2 years 4 months ago
About Jim Fixx– true–but before he took up running he smokes and ate the SAD and drank like a fish. His arteries were hardened befoe he began running, and when he ran he didn’t change his diet ( high carbs) much. So you could say the running may have given him maybe 10 years of active life versus an even earlier death by remaining with his previous lifestyle. I am not defending his ideas on running– I used to do 10K races and run 40-50 miles a week and think I was in good shape. But now I sprint twice… Read more »
BT
2 years 4 months ago

Yep, Bill Clinton was big on burgers and he loved unhealthy foods until he had his heart problems and decided to eat better.

Karl
Karl
2 years 4 months ago

Gotta love the “Running makes your heart explode!” – anecdotes – no confounding factors there at all, no siree…

Scott F
Scott F
2 years 4 months ago

Dr James O’Keefe MD is a cardiologist. In this video he gives a good lecture on excessive cardio and heart issues later in life. I know someone who trained for half marathons. He now has a pacemaker and his cardiologist said is was do to his “chronic cardio” https://www.youtube.com/watch?v=9g8eEYwtfSo

Karl
Karl
2 years 4 months ago

Scott,
there isn`t really much substance to O`Keefe`s hypotheses at this point; have a look at the article by Alex Hutchinson I recommended below.

Karl
Karl
2 years 4 months ago
Ahh yeah, those horrible, oft-cited “dangers of causing chronic inflammation by doing frequent cardio”…the only problem is, studies actually demonstrate no such thing – as long as overtraining is avoided, of course, as doing too much can attenuate or even reverse the benefits of pretty much any mode of exercise. Were one to apply the reasoning behind the “chronic cardio” concept across the board, people would have to be scared away from recreational strength training, too – with a reference to the massive joint problems of middle-aged professional powerlifters. Ironically, Mark himself conceded this a while ago in a post… Read more »
Karl
Karl
2 years 4 months ago

“…evidence is mixed for combined/anaerobic sports.” (Needless to say, there are probably confounding factors at play, though.)

PS: “Will Running Too Much Kill You? – The annual look at the current state of the evidence.” by Alex Hutchinson is a fairly decent summary on the topic.

MJM
MJM
2 years 4 months ago
I can relate to David’s issue regarding competitive cycling on low carb diet. I’m am medical doctor and avid cyclist trying to work this stuff out. As I understand it, ketoadaption allows for minimal glucose utilization during aerobic exercise. But, albeit less, glucose is still required by brain. I have been experimenting on 3-4 hour rides and races, finding significant value in 1) maintaining low carb, high fat diet and eating big breakfast 2 hours prior to ride/race (ie not carb loading), 2) using superstarch prior to ride (3 scoops) and during a ride after 3 hours (1 additional scoop… Read more »
Kelda
2 years 4 months ago
I agree with you. I rode end to end (in UK, 1,000 miles in 9 days) staying Primal, I didn’t carb load, I used rehydration salts in my water bottle. I ate nuts and some dried fruits on the bike (8 odd hours a day), and survived much better than the rest of the bunch I rode with (at the pitstops I stripped out the salad and protein from the bread rolls and ate that and sometimes had an apple! I estimate I had perhaps 200 g of carb total daily which given I was riding more than 100 miles… Read more »
Emelee
Emelee
2 years 4 months ago
Agree. As I read David’s question, I could completely relate, as I’m an avid (very low carb) cyclist. And I happen to be 55 also – a “healthy, lean, active” 55 yo woman. I was going to suggest SuperStarch – which I use – but others beat me to it. I love SS – for all the reasons MJM states. I can do high miles (80+) with plenty of climbing on a VLC b’fast, a dose of SS before, and a dose in the middle, and feel GREAT at the end. I eat NOTHING while on the bike. Granted, I’m… Read more »
Tom Kirkendall
2 years 4 months ago

Peter Attia, an endurance athlete who follows a ketogenic diet, recommends Super Starch, ( http://www.generationucan.com/super.html ), a relatively new training aid that apparently provides the energy boost of carbohydrate without the insulin spike. I have not tried it, but Dr. Attia has been using it for quite some time and swears by it.

TWA2W
TWA2W
2 years 4 months ago
I think it’s telling that runners come down with heart and lung problems later in life yet running is considered a healthy activity. Like Jim Fixx and Bill Clinton? Jim was found on the side of the road dead, still in his running gear. Do you have evidence or this?? More likely diet related in both cases. There is no evidence that I know of that shows runners have more heart and lung problems as they age. Anything I have seen shows just the opposite for endurance athletes. There are a few reported cases such as Fixx and Clinton but… Read more »
Christine
Christine
2 years 4 months ago
My husband has been doing endurance cycling for many many years & is very competitive. His best friend (also an endurance cyclist) died a few years ago suddenly of a heart attack, not knowing he had any heart problems. My husband had never had any heart problems & has no members of his family with heart problems. He has a computer programme so that he can monitor his training & it comes with a heart rate monitor. Anyway, one day he noticed that the heart rate monitor had shot right up, so he just assumed that it had gone wrong… Read more »
Karl
Karl
2 years 4 months ago
You are probably on to something here, but suffering from tunnel vision with regard to your interpretation: True, endurance athletes are at a greater risk of developing atrial fibrillation than “Average Joe/Jane,” but the same goes for pretty much any sport that isn`t exclusively anaerobic (ATP-CP system-dependent, to be more specific) – and that encompasses most sports: Seeing as people exclusively practising to improve their shot putting/javelin throwing/olympic weightlifting skills are a tiny minority among recreational athletes, pretty much everyone who exercises vigorously “for fun” with regularity has to accept a higher AF risk as a side effect; the higher… Read more »
Keiran
Keiran
2 years 4 months ago

I would definitely buy a PB cookbook devoted entirely to offal.

Paleo Bon Rurgundy
2 years 4 months ago

Check out at “Offal” and “Odd Bits”.

Joe Bob
Joe Bob
2 years 4 months ago

Generally runners do not run for health reasons, they run because they enjoy running. Swimmer swim because they enjoy swimming, cyclists pedal because they enjoy cycling.

There’s more to life than living to be 102 years old.

meepster
meepster
2 years 4 months ago

I dunno – if chronic endurance exercise actually reduces lifespan and healthiness, people need to know about it. Yes, there’s more to life than living to be 102, but if you think you’re doing a good thing for your body and actually are damaging it instead, you should know it.

And lots of people believe they’re doing something healthy by chronic cardio, even if they don’t enjoy it. I tried running for a while and hated it – but did it because I thought I had to. Luckily I didn’t stick with it for too long.

Karl
Karl
2 years 4 months ago

The thing is, “chronic endurance exercise” actually doesn`t seem to “reduce lifespan” – the available data suggest the opposite, in fact…(observational data corrected for confounding factors, as RCTs on this question are pretty much impossible, for obvious reasons..)

Willow
Willow
2 years 4 months ago

Here’s the linked study: http://www.nature.com/ncomms/2014/140415/ncomms4654/full/ncomms4654.html#axzz30Cf4MqWY
It got mixed up with MDA somehow. It was probably a copy paste error 🙂

Kurt
2 years 4 months ago
David’s chronic leg fatigue sounds like overtraining, likely caused by inadequate recovery to me. Inadequate recovery in this case may not be due to inadequate rest or training too hard, but instead on a lack of restoration of muscle and liver glycogen lost as a result of intense effort. Mark alludes to this. You don’t need to go completely non-primal/paleo or buy a bunch of supplements and goos to get by. Focus on primal/paleo foods outside your training window. Fruit with a little protein beforehand works to get me through 60-90 minute intense interval rides on just water. Immediately after,… Read more »
Dr. Anthony Gustin
2 years 4 months ago

More organ meat for all!

CM
CM
2 years 4 months ago
I’m about to start training for a 2 day 120km cycling ride that we do for a cancer fundraiser in the summer. We are supposed to do long rides, increasing distance weekly, to get our butt used to the sitting and of course build our endurance on the bike. But what I’m wondering is: Do the sprint runs that I LOVE to do help to build the kind of endurance we will need for a cycling event of this type (there are some steep inclines). If so, I will, lessen the cycling training km’s, keep up the sprint runs, weight… Read more »
Gayle
Gayle
2 years 4 months ago

I just started my daily read of certain sites. I opened Seth’s Blog site and was informed that Seth had died while hiking on Saturday. Just thought you’d like to know….

Bill
Bill
2 years 4 months ago
For me, Ray Peat underscores some ideas that are often confused; 1. There are broad, underlying principles that are applicable to virtually everyone (populations). 2. There are a ton of micro-tweaks that are appropriate for individual circumstances (including activity level, pre-existing conditions, particular sensitivities etc). I have no doubt that Ray Peat is exactly right for himself, I’m just not sure that Ray Peat can be extrapolated out to populations. So the common mistakes are; 1. Dismissing the notion that there are things virtually everyone in a population should be doing (there will always be very few individual exceptions). In… Read more »
Dr. Jason Bussanich, DC
2 years 4 months ago

Excess red muscle meat increases Iron. Excess iron over a certain amount contributes to insulin resistance in the liver believe it or not! It’s great to give blood to lower your levels, especially if you don’t exercise as much and aren’t having a lot of tissue overturn. I think they suggest less than 100 on the iron scale so give blood as a male. Women are protected due to their period cycles. Lucky them. Not an issue in hunter gatherers, but maybe they have more parasites and blood loss in various ways.

Miriam
Miriam
2 years 4 months ago
The muscle meat issue is close to my heart. I live in China, and the food sources around me are very toxic. Vegetables are utterly unsafe-since we stopped eating them about 18 months ago we’ve felt much better. Every time my roommmate has them now she breaks out and itches everywhere; even the so-called “organic” ones, which even corrupt gov testing admits 30% of are fake. If we eat out, even at the nicest restaurants, we get boils a few days later and feel awful. We’re able to get pastured chicken eggs, which we eat raw, pastured pork bacon and… Read more »
Drumroll
Drumroll
2 years 4 months ago
Yesterday I actually saw someone with a knee brace on BOTH legs, some sort of back support device, and who knows WHAT on her hips (never seen anything like it but it looked painful). And she was running her ass off (we’re def talking about 70% or over max heart rate here). And her running technique was horrible, HORRIBLE. Probably the source of half of her problems. I didn’t know what to think. Was she following her docs “advice” to get more physical activity? Was she doing more harm than good here? Seriously though, when is enough, enough? When have… Read more »
Chris L
Chris L
2 years 4 months ago

I don’t believe the inner organs make up 75% of the meat on the animal. Inner organs make up 12% on body weight of the human for example. I don’t believe there’s much to the muscle meat is inflammatory theory, muscle meat has all the amino acids you need. The type of meats I do believe are inflammatory are processed meats, lunch meats, sausages, frozen burgers, all that stuff with nasty preservatives and other additives

Scarlett Hermann
11 months 20 days ago

Can I use my rice cooker to make quinoa?

Healthy Eating
11 months 11 days ago

I’m gone to tell my little brother, that he should also visit this webpage on regular basis to get updated from most up-to-date gossip.

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