Should You Sleep-Low to Boost Performance?

Should You Sleep-Low to Boost Performance FinalThought experiment time. Say you train hard, hard enough to deplete a signifiant amount of glycogen. Your muscles are empty, sensitive to the effects of insulin, and screaming for a couple potatoes to refill glycogen. What do you do?

In most circles, the answer is to eat those potatoes and refill those glycogen stores. And why not? The post-workout period is a special window of opportunity for eating a bunch of carbs and having them go to the right places with minimal insulin required. They won’t contribute to fat storage. They’ll go straight to your muscles. Restocking glycogen sets your muscles up to repeat the hard work and keep up with your training. It makes sense.

What if you didn’t eat the potatoes after a hard workout? What if you abstained from carbs entirely after a glycogen-depleting workout? What if you just went to bed without any (carbs in your) supper? What if you were an elite athlete and skipped the carbs?

That’s exactly what a team of French researchers had a group of highly trained male triathletes do, according to a study released a couple months back.

They were exploring the effects of a “sleep-low” eating regimen on the type of performance indices relevant to endurance athletes. It was a really interesting study.

First of all, everyone was highly-trained. These were elite triathletes, the cream of the crop. No weekend warriors in sight. They were split into two groups: a control group and a “sleep-low” group. After a three week induction period of identical diets, supplements, and training, the experimental phase commenced. Both groups ate the same total amount of carbohydrate (6 g/kg bodyweight) each day, just at different times. The control group ate theirs with every meal. The sleep-low group ate theirs at breakfast and lunch.

Training was identical for both groups. For four days straight each week, both would follow a routine.

In the afternoon, they’d perform high intensity training sessions, either 8×5 minutes cycling at 85% maximal aerobic power output (MAP) or 6×5 minutes running at 85% MAP (alternating each day) with a minute between each interval.

In the morning, they’d do low intensity aerobic (LIT) work before breakfast: an hour of cycling at 65% MAP.

The sleep-low group ate carbs at breakfast, lunch, and a pre-workout snack. Then a HIT workout. No carbs until breakfast the next day after the LIT session.

The control group ate carbs at breakfast, lunch, post-workout, and dinner. Breakfast came after the LIT session.

After three weeks, the scientists subjected both groups to submaximal (LIT) and supramaximal (HIT) cycling performance tests, Vo2max tests, and a 10k run (to simulate the final leg of a triathlon). The sleep-low group performed these tests in a “low-carb availability” state (low glycogen). The control group performed them in a carb-replete state.

What happened?

Submaximal efficiency (power output per calorie burned when pedaling at moderate intensity) greatly improved in the sleep-low group. The control group saw very little improvement. This is a crucial biomarker for endurance athletes. If your submaximal efficiency is high, you get more power out of each stride/pedal/stroke with less energy required. That means your “easy pace” is faster than the other runners.

The sleep-low group’s supramaximal capacity also saw a major boost. They were able to cycle at 150% of their Vo2max for around 12-20% longer than before. There was very little improvement in the control group.

In a 10k run test, the sleep-low group shaved around 3-5% off their times. The control group shaved just 0.10% off.

Even though they were all quite lean to begin with and this wasn’t the purpose of the study, the sleep-low group lost more body fat.

This was the “have your cake and eat it too so just long as it’s not at dinner” study. When they did HIT, they were glycogen-replete and dominant. When they did LIT, they were running on fat and just as dominant. They weren’t on a keto diet. They rapidly reached the very-low carb/ketogenic state for a good portion of the day by depleting glycogen and failing to replace it, from the afternoon snack to the post-workout breakfast. They weren’t just “high-carb.” They were smart carb, filling the glycogen, depleting it, and forcing their bodies to run on fat for a while.

What’s truly remarkable is that this was a short-term study. Three weeks of experimental conditions were plenty for the benefits to accrue and amass. They didn’t have to spend six months getting adapted. They didn’t go through a keto induction period. They manipulated the pattern of energy substrate use through carb and workout timing. This is simple stuff anyone could do. And if the elite athletes (triathlons are no joke!) can benefit from it, I’m pretty sure the average person trying to improve performance will see benefits.

Another cool part is that even though the sleep-low group performed HIT workouts in the carb-fed state throughout the study, they were tested in a carb-depleted state and still saw huge improvements. They “trained low, raced low” when it came to submaximal endurance and “trained high, raced low” when it came to supramaximal capacity—and both modalities improved. That’s huge.

What’s going on is forced adaptation. By waiting to eat more carbs immediately after you deplete yours, your body has to upregulate fat metabolism. You will get the carbs soon enough—you’re going to eat them the next day after your morning workout—but you make your body wait a bit. In the meantime, it has to work with what it has available: fat. This study is just the latest to show that forcing these adaptations can have real benefits.

If you wanted to try this out yourself, you could follow the schedule in the study. You’d have to have a lot of free time and flexibility, but it’d probably work.

If you’re a normal person with a normal schedule, you could do a truncated version. Eat carbs before your high intensity workouts and none after. Go for a walk or a light jog in the morning before breakfast. Eat carbs with breakfast and lunch and perhaps a snack before your high intensity workout. You probably don’t need the 6 grams of carbs per kg of bodyweight the athletes ate in this study. Whatever you do, be sure to really deplete glycogen and wait for 12-16 hours to refill it.

Standard low-carb dieting promotes similar adaptations, but it works more slowly. Glycogen depletion takes a while if you aren’t training intensely, so you can speed up the process by throwing in some sprint, circuit, or HIIT workouts.

I know from personal experience that this can work (hence Primal Endurance). Once or twice a week, I like to fast after workouts. That’s a slightly more extreme version of post-workout carb abstention, but it’s the same idea: withholding food and forcing your body to adapt. This increases growth hormone (important for fat burning and cellular repair) and speeds up fat adaptation.

So, who’s interested in trying this out? Anyone? Let me know how it goes in the comment section!

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About the Author

Mark Sisson is the founder of Mark’s Daily Apple, godfather to the Primal food and lifestyle movement, and the New York Times bestselling author of The Keto Reset Diet. His latest book is Keto for Life, where he discusses how he combines the keto diet with a Primal lifestyle for optimal health and longevity. Mark is the author of numerous other books as well, including The Primal Blueprint, which was credited with turbocharging the growth of the primal/paleo movement back in 2009. After spending three decades researching and educating folks on why food is the key component to achieving and maintaining optimal wellness, Mark launched Primal Kitchen, a real-food company that creates Primal/paleo, keto, and Whole30-friendly kitchen staples.

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62 thoughts on “Should You Sleep-Low to Boost Performance?”

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  1. Yet another supporting example of conventional wisdom, when eschewed in another setting, biting the dust.

    1. The research into this is actually a lot less definitive than you might think, and it’s more important to get enough carbs over the course of the whole day, rather than worrying about squeezing them into the post-workout window. The idea that you should only eat carbs right after a workout is just unnecessarily restrictive: exercise increases insulin sensitivity for up to 48 hours after you hit the gym, so there’s no magical 30-minute window to cram in your carbs for the day.

  2. Endurance athletes try this at your peril. Everyone is different, and there are certainly benefits to a ketogenic lifestyle. But for many it absolutely destroys performance within a relatively short period of time. And any regimen where you struggle to continually supplement with nutrients you should be routinely receiving through your diet bears questioning. Experimenting with diet and performance is generally worth a try, but I have not found many/any endurance athletes who have made it work for more than a relatively short period of time. Eating for optimum health is the best performance boost there is.

    1. That’s precisely why this strategy could be a good alternative for those who are not wanting to go low-carb. If you didn’t notice, all of these athletes are eating an overall extremely high carb diet in terms of “primal” standards.

    2. But, thank God for those who *do* try things at their own peril.

    3. I’m not sure are correctly interpreting this article. Its not about persistent ketosis, or even about carb restriction. Its about nutrient timing and adaptive responses that do boost both performance and health markers.

      1. I agree Jay. Daily carb intake was the same for both groups. The structure of no carb at dinner to create extended ‘adaptive’ period followed by low intensity morning session seems to be well thought out. I’d be interested to see the outcome if breakfast was the no carb meal.

    4. I hope this doesn’t come across more confrontational than I intend. My assumption will be that those of us who visit Mark’s site, and others with similar goals, do so trying to further our knowledge and perfect our own eating and health goals.


      -Zach Bitter ( current record holder for 100 miles on a track and distance run in a 12 hour period among other accomplishments.

      -Sami Inkinen (Wold Class tri-athlete) and Wife Meredith row 4000 kilometers from California to Hawaii unsupported. The record for a 4 person team was 60 days. The accomplished the feat in 45 days with 2 less people. Rowing the equivalent of 2 marathons each every day. Remarkably, Meredith did not lose one pound and Sami only lost the msucles he didn’t use, for example his biking muscles. (

      -Article about professional cyclist Dave Zabriskie, ultramarathon runner Timothy Olson, and gold-medal triathlete Simon Whitfield. ( Of note is our own Mark Sisson being mentioned and Timothy Olsen setting the record in the 100 mile race through the Serias known as the Western States 100.

      -Dr Peter Attia’s self experiment ( That’s part 4 but all of limited posts are worth reading. He shows his improvement in aerobic base, 60% VO2 Max, and VO2 max numbers

      -Jeff Voleks FASTER study ( that’s just a quick synopsis, but there is plenty of information available including an indurance planet posdcast interviewing him about the study and results.

      -World #1 Tennis Player Novak Djokavic ( discusses his success with limiting sugar, gluten, and dairy.

      – Article discussing the LA Lakers and professional golfer Phil Mickelson changing to a low carb lifestyle. (

      -Article about LeBron James switch (

      -Article about the All Blacks who won the Rugby World Cup, and are mentioned in Cereal Killers 1 &2, mentioning their LCHF lifestyle (

      And my own experience as a high level racquetball player is to eat very low carb and participate in weekend long tournaments with very little food or carbs overall. And as others have mentioned the study wasn’t low carb, just concerned the timing of the carb meals.

    5. Not to be rude, but I disagree entirely with your statement on supplementation. If you honestly think you’re going to get every nutrient, from vitamins and minerals to whatever other trace metals etc, from your diet of green leafy vegetables, protein sources and fats, you are wrong as the day is long. I doubt you could find any paper/study on nutritional values from today’s time where it lists amounts of vitamins and mineral content. It will most likely be 50yrs or more old. You are what you eat, and so is that vegetable. So unless you’re growing your own garden and are amending the soil with trace minerals like rock dust, worm castings ,mulch etc, you will have a factory farm raised vegetable with the bare necessities to get that plant grown and to market. That would be a calcium(dolomite) NPK and maybe another chemical fertilizer to promote fast growth. Take a soil sample and take it to any ag department in the county and ask for it to be tested. If it has any agricultural farm use, it will be depleted of nearly all traces of minerals except for the above mentioned and others at levels so low it would be negligible. As a reference I grew up farming and I now garden for my family for a large portion of our meals. So in summation, plants do not make minerals, they get it from the soil and vitamins and other nutrients are produced by the plant by using the minerals. Analogy You can blow a balloon up but it’s still lacking any substance on the inside even though it’s big and full.

  3. So, what if I workout in the early a.m. before breakfast? Would I then eat my carbs for lunch and dinner or still breakfast and lunch? I usually don’t eat anything until about 10 am.

  4. “Whatever you do, be sure to really deplete glycogen and wait for 12-16 hours to refill it.”

    How do you know when you’ve depleted your glycogen?

    1. Ditto on that question as well. When I work out it is usually between 6 and 7 a.m. I guess I could just do a keto-like day after a hard workout, and then refill carbs the next day?

  5. Was this study done on all male athletes? I am curious as to whether it would be the same for both male & female athletes….

    1. The abstract doesn’t state whether they were male (a huge blind spot for researchers), and the New York Times article on this doesn’t say either. But I think I can guess …

    2. He says in the article it was all make athletes. Just from anecdotal evidence, here and otherwise, women of childbearing age don’t seem to do as we with intermittent fasting/keto/very low carb, so I’m doubtful it would have found the same benefits for women. You could always make yourself the experiment though and try it!

  6. The one thing I’m curious (haven’t read full study) is whether the low carb folks slept OK. Carbs at dinner seem to really help my serotonin levels which then seems to promote better sleep.

    1. Yes, this is my question too! I have started fasting before and after my morning workout to boost growth hormone and have no problems doing that, but if I don’t eat some carbs with dinner then my sleep suffers a bit. I need carbs at night.

      1. Are you sure it’s the carbs or could it be the fiber? I’ve heard that fiber actually can be helpful in promoting restful sleep and too many carbohydrates can actually be detrimental to sleep just like too much protein or too much fat before bed, though for a different reason than the latter two.

    2. That’s my concern as well. If I’m even a little hungry I can’t fall asleep, and if dinner isn’t late or substantial enough, I wake after a few hours. Insomnia is no joke, so if I ever fast, it is from waking to about 4:00pm, and whatever exercise I can manage is usually in that window.

      But then I’m an old lady with a bunch of autoimmune disorders, so today’s article probably doesn’t apply anyway 🙂

      1. If you haven’t already, try drinking chamomile tea before bed. I have the same sleep issues, but the tea (I use Trader Joe’s brand) knocks me out and keeps me sleeping through the night.

      2. I don’t sleep well without magnesium supps, i need 400 mg per day with the supps, my body apparently had high demand for magnesium. It’s my only medication other than DMSO on the skin for tendonitis (caused by sports which I like too much to stop). Magnesium is the magical sleep supplemetn!

      3. I hear you Paleo Lady, I have the samne issue(s) though I’m male. Can’t sleep at all if not eaten an hour or so before bed.

    3. I have had the same issue. I did the 21 day challenge, and about the beginning of week 3, I started to wake at 2 or 3am. I continued with a second 21 day challenge with Bee the Wellness and Vanessa suggested that I have sweet potatoes with my evening meal. Once I did that, I slept great. I was pretty low carb diring the challenges. She thought it was my liver going into glucenogenysis mode. I slept great after that.

  7. I tried something like this accidentally a while back. I was eating pretty low carb, and I added HIIT three days a week for about twenty minutes. I was completely exhausted for the whole evening– as in like a slug, all I wanted to do was lay on the couch, and as a relatively active person at a healthy weight, that wasn’t normal for me. That only lasted about 3 weeks until I figured out adding carbs after helped the lethargy. I wonder if the test subjects experienced that or not. Anyway, I might give something like this a try again, with modifications as needed, but it’s not worth the lethargy that followed in my own case.

    1. I agree with Tara. Eating starchy carbs after a workout, keeps me from feeling lethargic. Learned the hard way. Even eating starchy carbs (small amount) helps too. My body fat levels always remain the same as long as I am eating Primal :).

  8. My mom has been doing this by accident for about 3 months and has lost 20 lbs! She told me she goes dancing after work (which I think is high intensity for her) and just has a protein shake or nothing for dinner. Now there’s scientific evidence to back up her method!

  9. I’ve been following a carb cycling and intermittent fasting program for a few weeks with great results. I’m definitely going to tweak the timing of my workouts to take advantage of depleted glycogen stores.

  10. Carey Reams was teaching this decades ago: big carbs for breakfast and lunch, light salad and maybe some meat for supper. He was helping people recover from cancer.

    1. Except it’s not the same thing. In fact it’s the complete opposite. They weren’t fasting at any point outside of sleep. Instead they were basically front loading their carbs in the morning and afternoon and only consuming fats and proteins in the evenings.

      At best you could claim it is similar to an evening fast into sleep but few people practice that way and favor either a sleep into morning fast or all day fasts. Plus those would be true fasts with no significant calories. This was not that, this was only limiting carbohydrates for a certain period.

  11. So eat carbs like a king for breakfast, like a prince for lunch, and like a pauper for dinner? 🙂

    1. For those of us dealing with Adrenal Fatigue, the opposite is true. Lower carbs at breakfast and lunch and then majority of carbs with dinner. All meals having protein and fat and fiber as well. Too much protein at night can raise cortisol which can cause insomnia. Highest cortisol levels should be in the morning. Carbs at night are conducive to better sleep.

  12. I have been holding off eating after a workout, especially HIT, but to enjoy the lingering hormonal uptic in hgh and testosterone. Hadn’t thought about the fat adaption benefit.

  13. Interesting article. I have been experimenting around staying in ketosis before and after workouts purely because I hate packing lunch and like working out mid-day.
    I have a keto shake for breakfast, skip lunch, do strength training or HIIT in the early afternoon, then eat in the evening. Often it’s pretty low carb: veggies, nuts, meat, cheese though sometimes I’ll have a starchier veggie or some fruit.
    I was super nervous about trying this, but it was so convenient and worked out great for me. I hate having to figure out what’s in the fridge for lunch every day and now I don’t have to! So far my energy level, lifting, and muscle mass have increased and I feel great. The only time I felt hungry was when my fiance (unbeknownst to me) switched the 1/2 cup coconut milk in the shake for a 1/2 cup of milk for a few days. Once I figured it out and switched back, it’s gone back to normal.
    I’m definitely not recommending that this is great for everyone. Just an interesting aside. Experimenting with eating and workouts and finding out what works for you is half the fun!

    1. Great idea! Only thing more annoying than packing lunch is eating in my office, doing dishes…bleh. That’s really interesting about the milk. Thanks for sharing.

  14. “Both groups ate the same total amount of carbohydrate (6 g/kg bodyweight) each day, just at different times. The control group ate theirs with every meal. The sleep-low group ate theirs at breakfast and lunch.”….

    This certainly fits with the premise that paleolithic man eating what’s at hand, first thing in the morning… and then go hunting.

  15. Argh, I think this is almost the opposite of what I thought I just heard on a Sisson/Greenfield podcast. The just of that was better body composition moving all carbs to nighttime, that appealed to me for the reason of sleep that others have mentioned!

  16. So basically:

    Morning = Carbs, yes Please!
    Lunch before intense workout = Carbs, damn straight!
    After Workout = What are carbs? Never heard of these things called “carbs”

    Fuel to train, but I suppose it depends on what the person’s goals are. If your goal is either strength, performance, size/gains or anything of the like, you have to eat, there is no if’s, and’s, or but’s about this. This would include probably having square meals all throughout the day.

    If your goal is maintenance or fat loss, maybe this is the way to go. Either way Grok didn’t go out of his/her way to lose fat or increase their strength or performance; both of which throw our body out of homeostasis.

    Our natural eating pattern probably was a big meal for either breakfast or dinner with (depending on if you had dead boar or not). Then little to no lunch. I would suspect breakfast was the bigger meal most often as a dead carcass would provide food for many days which I’m sure grok would feast on upon waking.

  17. I wish I could implement this, but my problem is that a) if I don’t work out first thing in the morning, I won’t work out at all, and b) if I have to eat at one time during the day, it has to be at dinner time as I can’t sleep when I am hungry.

  18. I teach spin 8 am 4 times a week which is big time HIIT I then do the LIT in the evening. (training for Ironman) Sometimes I swim (LIT) after the HIIT or do the Max sustained power sets (2-3 times a week). So this is my experiment. No carbs until 6-8pm 10-12 hours after the HIIT with my dinner. At lunch (I don’t eat breakfast) with protein only. I might have to add a protein shake after HIIT to keep going. Humm… sounds weird. But I will report back.

  19. Out of curiosity I looked up MAP, since I could not recall what relationship it had to FTP, but did remember Alex Simmons using MAP and indeed he has handy tables detailing the zones.

    65% MAP is actually high tempo, looks about comparable to Sweet Spot to me, while 85% MAP is the higher band of threshold or TT pace.

    Now this shouldn’t probably surprise anyone given that they’re elite (those 1 minute long “recovery phases” are kind of a dead giveaway…), however if you’re reading the post and picking up “low intensity” and “high intensity” as general concepts, you may be getting the wrong idea; for the average cyclist “low intensity” actually means all-day pace/endurance aka Z2/L2.

    Also, since there seems to be a fair few mistaking this post for “low carbing” or “going ketogenic”: read again, they’re eating the exact same quantity of CHOs, the guy above who said “nutrient timing” got it right.

    6g/kg is NOT low carb. Even using LBM instead of TBM for an average BW of 75 kg and, say, a decently lean 15% Fat, you’re looking at 380+ grams of CHOs per day.

    Most likely, these being elite, they’re eating more. Off the top of my mind elites tend to be in the 400-600g per day.

  20. This is very interesting as it goes against what I thought was the holy grail of carb partitioning, namely eating the bulk of them at night (in my case with breakfast skipping IF)! I usually do some fasted easy cardio and mobility before lunch and then a strength training session in the evening, so I would just have to squeeze all my carbs into lunch and afternoon snack and then have protein, fat and green veggies for dinner which would be no problem 🙂

    Now this study looked specifically at endurance training while my goals are strength and physique. The superior fat loss is definitely enticing and according to the study, the sleep low group also maintained more lean body mass.

    I suspect that muscle growth and strength gains would not be negatively affected by the sleep low protocol, but I’m not sure if a typical strength session depletes glycogen enough to trigger these benefits?

  21. This study is biased towards maximum performance athletes. If one is overweight and struggling to be active, this is out of their league. The overweight should limit carbs all day until they can achieve something like an unassisted pull-up, run an 8 minute mile, and hold al plank for 2 minutes. If one is competing as a triathlete, carb timing may be necessary for peak performance. This doesn’t apply for those of us that hope to someday complete a triathlon, rather than win one.

    1. Not trying to sound too snarky here but… “Unassisted pull up” is a man’s benchmark.

      The vast majority of women will never be able to do an unassisted pull up and that doesn’t mean that they are out of shape or unhealthy.

      I have amazing bone density and I am generally a very ‘heavy on the scale’ person. My entire life, – not even as a girl – have I been able to do a single unassisted pull up, rope climb, you name it. That said, my metabolic engine is awesome for my age and gender. Noticeable body composition improvements are *finally* coming as I shifted to a primal version of the AltShift program.

      Setting benchmarks like an assisted pull-ups or handstand push-ups for somebody like me is patently unfair.

      1. Please forgive my insensitivity. In my defense I know several women that can do more pull-ups than me. One is five years my senior. My point was carb tuning is for competitive athletes not for the majority of us that simply don’t want to feel embarrassed in a swimsuit.

        1. Thanks. I’ve seen those gals at my Crossift gym also. They are all ages teens – early 30s max, in the “firebreather” category. The rest of us females look on with our jaws dropped. Fun to watch, unrealistic to emulate.

          I get the “look good naked” drive. If I ever get there, I might also be able to do a pullup with a less beefy band to accomplish the trick than is currently required. Fingers crossed.

  22. No surprise to me. I’ve been doing the Sprint 8 HIIT workout for over a year now. The guy that invented it sais you should eat at least 20g protein directly after the workout and hold out on carbs as long as possible.

    The idea is that this boosts the post workout Human Growtrh Hormone from this type of HIIT.

    So carbs would immediately stop the surge of HGH.

  23. Wow. This is what keeps me coming back here! Thanks, Mark. You answered a question I didn’t even know to ask! I have bit of info re: a low intensity (kind of accidental) version of this regimen and it’s effect on a post-menopausal, not-particularly-fit, 65 year old lady.

    Eight years ago, I was 100 lbs overweight, and completely out of shape, but otherwise healthy. Since getting serious about my health, I’ve lost 100 lbs and my fitness level has been steadily improving, but we are not talking elite athletics here! I follow a primal eating plan (about 70/30) with no exercise other than some mildly challenging group hiking on weekends. That’s it. I’ve haven’t been any version of fit since my 20’s, and even then it was no better than average. Seriously, I’m that kid who always got picked last for the Phys Ed teams and NEVER played any kind of sport. I took library books to phys ed!

    So… last summer I read about the Alzheimer’s protocol ( and implemented it, somewhat haphazzardly (Mom’s got AD, and I have half her genes, but no symptoms). Specifically, the no sugar and “12 hour fast/no after-dinner snacking” part applies here. That was pretty easy, and I’ve been fairly consistent with it. So while I don’t really exercise except for my hikes, for the last 6 months I been eating eating moderately low carb all day with very low carb dinners (usually), followed by a 12 hr. fast. So that’s a vague approximation of this study — right? Not really close to the regimen, but kind of in its neighborhood — or maybe in the same town? 🙂 In any case, I was “sleeping low.”

    So here’s the interesting part. Day before yesterday, I was hiking with a very fit friend (runs 6 miles/day) over pretty rough ground and I was THE BEAST. I was jumping over logs, climbing rockfalls, skipping on rocks down the creek, scrambling up bluffs, and crawling under thorn bushes. And waiting for my companion to catch up. Seriously, I’ve never experienced anything like this in my LIFE. I was baffled! All of a sudden I was both fit AND flexible. Even my balance was better. It was like a normal person walking up and discovering that they were a fabulous ballroom dancer, with no practice.

    This soooo isn’t me — I’m still the one who brings up the rear in group hikes. (Recently, I ‘ve noticed that I was keeping up better.) And I feel GREAT. I feel like I’m 25 again.

    Oh, and I keep losing weight — very slowly, but without even trying.

    Sleep low, people, sleep low!

    1. This is amazing, Ann, how lovely to hear of your transformation into The Beast!

    2. Ann, I LOVED your post and story! As a 60+ year old, Crossfit fanatic, I love hearing about individual “Beast-Mode” stories! Yours truly inspired. Thanks

  24. So, if i’m doing PBF this is not needed right? Because the workout doesn’t require too much glycogen to get through it

  25. “When they did HIT, they were glycogen-replete and dominant. When they did LIT, they were running on fat and just as dominant.”

    What does dominant mean in this context?

  26. Does this still apply to the more traditional full-body strength workout? I would love to try if so. My carbs have been in the 200-250g range but I’m doing three strength workouts, a sprint workout, and the other days are pretty active playing sports or hiking with my 3 year old. Thanks!

  27. Judging by most of the comments so far people are really missing a key point about the carb timing.

    The big takeaway of the article was NOT that we now need to flip on its head the idea of when was the best time of day to have carbs (morning versus evening).

    The big takeaway was to forget about that 30 – 60 Minute refill carbohydrate window post-workout and instead stretch it out to a 8-12-hour window, by my estimate.

    In other words if you do a MORNING HIT workout, stick to proteins and fats the rest of the day and have your carbs in the evening. If you run it this way then you get the best of both worlds: the performance boost + late carbs for a sleep boost + late carbs when cortisol is low in the evening = better body composition. LIT walk or other movement later in the day also.

  28. Maybe there is little more to all this than simply going without carbs for 12-14 hours a day. Possibly one should spread their reasonable quantity of carbs out fairly evenly during the carb-eating period.

    Anyway, I’ve been trying basically what the article suggests, carbs at breakfast, tiny carbs at snack, carbs at lunch, tiny carbs at snack (totaling 100-120 gm), then a hard workout, then no carbs at dinner and none until breakfast. Last night, at 0200, zing! Wide awake. I am now going to try tiny carbs after dinner, for sleep purposes, and moderate carbs at breakfast.

  29. I’d like to ask a question here, because I don’t know where else to post it.
    I know I’m not the brightest bulb, just don’t have the education.
    After reading Mark’s Primal Endurance (for interest, never have been, nor will I be an Endurance Athlete) I don’t understand the difference between chronic cardio, and the training Endurance Athletes do on a daily basis, for hours, and hours, be it running, biking, swimming etc. Why is that not chronic cardio?
    Thanks in advance for your illumination!

  30. Where does gluconeogenesis (GNG) fit in with this? If you eat protein after a workout, won’t your body convert some of the protein into glucose (using GNG) and restock your glycogen that way? And what drives GNG in any case? How does your body decide how much protein to convert to glucose? Is it strictly driven by a glycogen shortfall, or will GNG ‘keep going’ and produce ‘surplus’ glucose? Or does muscle repair take priority over all this in how proteins are used? (6 questions there. Sorry about that, folks. Answers to any one of them would be appreciated though)

  31. This is so interesting! I’m a 41 year old CrossFit athlete and I’ve been Primal and IFasting for the past 9 years. I definitely play with carb cycling and train to get my body into a depletion state often but I usually train depleted rather than the study suggests: train carb replete and deplete after.
    My typical routine is carbs at night (around 80-100g) then strength training / HIIT on bulletproof with whey as pre-workout, no carbs after (lunch protein and fats), train in the afternoon (depleted because I didn’t have carbs earlier) and carbs post afternoon training.
    Would this work the same way? Considering that the carbs night before you put me into a carb replete state for the morning session? And I won’t have carbs again for 24 hours after.
    Should I keep this routine or experiment differently?
    Thank you!

  32. This study is fascinating and I have implemented in my workout schedule. The results are : better recovery, better lean mass gains and in addition more restful sleep, in particular if I completed a intense workout in the afternoon.

    I would like to know about using a protein shake as a ‘sleep low’’ dinner option ? As this will have an impact on insulin …

    Other options include simply a scoop of collagen with or without a healthy fat.

    However with a high intensity traIning schedule I have wondered about what is best for overall recovery and long term training ?