Meet Mark

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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November 17, 2008

Dear Mark: Post-Workout Fasting

By Mark Sisson
79 Comments

Empty BowlBefore I jump into this week’s Dear Mark post I wanted to direct everyone’s attention to Andrew Rubalcava’s site, Go Healthy Go Fit. Andrew just published an interview with me. Here are just a few of the questions I answered:

Who have been your top 3 favorite bloggers over the years?

How did you get involved in physical competition such as your experience as a triathlete?

If you could give a few words of advice for those who are just beginning to enter a world of health and fitness, what would you say?

Check out the interview here, and check back on Thursday when I’ll be publishing Andrew’s guest post on how to stay healthy no matter what type of lifestyle you lead.

______________________________________________________________

For this week’s Dear Mark I thought I’d follow up on the issue of post-workout nutrition from a couple of weeks ago. I mentioned in Dear Mark: Muscle Building and Carbs that I fast once in awhile after a workout. I’ve gotten a lot of comments and messages about this point since that post. So, here’s my take on PWO fasting as promised!

As I mentioned in the earlier Dear Mark, after a workout is prime opportunity for protein synthesis. For that reason I usually do a high protein snack in the first 30-60 minutes to capitalize on that benefit. (Carbs, as you recall, aren’t necessary for the enhanced synthesis, and I don’t recommend them in any form after a workout that’s under an hour’s time.) However, I also occasionally choose to fast after a workout to maximize another physiological benefit – the rise in human growth hormone (HGH), which critically influences everything from bone density to muscle mass and organ reserve to general cell reproduction in the body’s systems.

As I’ve mentioned before in relation to intermittent fasting (IF), fasting is known to significantly increase HGH secretion. (Grok’s survival depended on the ability to hormonally kick start efficiency and preservation modes during the lean days.) Research has also consistently confirmed that intense exercise, particularly resistance training, also triggers a rise in HGH. While I can (and do) take advantage of each individual method, combining the two opportunities can maximize my body’s HGH release.

Furthermore, insulin suppresses HGH. Skipping the carb snack and subsequent insulin upsurge goes a long way post-workout. But skipping anything that might even mildly raise insulin levels (that heightened sensitivity in the muscles, you know!) can be better yet.

And I should add that I do this without worrying about a blow to muscle mass. Fasting occasionally post-workout, provided I maintain a high protein diet the rest of the time, doesn’t negatively impact nitrogen retention and protein synthesis. Just as I mentioned last week that the body won’t suffer if you don’t force reloading of glycogen stores with a shot of glucose after a workout, I’ll go out on a limb and say that you’re unlikely to waste away if you don’t fuel muscles immediately with protein as well. The fact is HGH has its own protein conservation potential. And, while the post-workout period is an optimum opportunity for protein synthesis, it’s not the sole time your body is able to use protein and provide for the muscles’ needs.

While I’m not suggesting fasting after every workout, I think it’s worth doing occasionally. (After all, Grok probably wasn’t successful with every hunt.) In the spirit of IF and recreating patterns of our primal ancestors’ lives, varying your eating/exercising/fasting practices ultimately allows for maximizing the hormonal and upregulating benefits of different physiological scenarios.

Finally, yet another means of naturally encouraging HGH release is getting a good night’s sleep. After a good fast (and a great workout), I find this part comes the easiest. Honestly, it’s the best sleep I get.

As always, thanks for your questions and comments. Keep ‘em coming!

DeathByBokeh Flickr Photo (CC)

Further Reading:

The Hype Over Human Growth Hormone

1 Meal vs. 3 Meals

How To: Intermittent Fasting

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79 Comments on "Dear Mark: Post-Workout Fasting"

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Holly
Holly
7 years 10 months ago

Hi Mark, Great post as always.
Where I work out is between 45 min to 1.5 hours (depending on traffic… oh Los Angeles) from my house so I tend to work out and then just wait until I eat dinner (generally 2-3 hours after I finish my work out). Would it be a good idea to start bringing a protein rich snack in the car to eat while I’m on my way home?

Son of Grok
7 years 10 months ago

Thank you for the post Mark. I know thhis should answer some of the questions out there. I too enjoy fasting every now and then after a workout. Only occasionally though as I also thouroughly enjoy chowing down after a good hard workout too.

The SoG

Earth Beauty
7 years 10 months ago

Very nice blog! I was so hungry after my two hour hike yesterday! I had fish, cereal, yogurt, ravioli and a salad. Just went on and on. Plus I was really tired, had a small breakfast and stayed up late the night before. I like this idea of an IF occasionally after a workout. I slept very well last night.

Andrew R
7 years 10 months ago

Hey Mark,

I just wanted to say thanks again for the interview!

I also had a question regarding IF post workout. I tend to hit the gym sometimes pretty late at night. If there isn’t enough downtime between your workout and bedtime, is it a good idea to just not eat until the morning or should you at least eat something?

And thank you for letting me write the upcoming post for Thursday! I’ll make sure to let my readers know.

All the Best,

Andrew Rubalcava

jaime
7 years 10 months ago

How long does the post-workout fast go on for? An hour? Three? Til the next day?

Alma
Alma
7 years 10 months ago

Loved the interview, and glad to hear you’re a fan of Jack Lalanne. I was worried only us old fogies (76 years young) had heard of the original fitness guru!

Roelant
7 years 10 months ago

Hey Andrew,

I’m not sure if Mark covered it, but I think Art DeVany will work out and occasionally skip dinner. If you do this intermittently, it will not work against you as both he and mark have stated, sometimes Grok just can’t get the bear no matter how hard he tries.

I’m glad this post confirms what I’ve been doing. On hard workouts (ie. glycolytically demanding) I’ll have a post workout meal, but on Alactic or just heavy lifting days, I can go with a bit of a fast pwo.

Mark Sisson
Mark Sisson
7 years 10 months ago
The main idea in the post today is to confirm that it’s OK not to eat after a workout once in a while. I don’t do it all the time, but I also never freak out (like my body builder friends) if I skip a PWO snack or meal – or two. I can’t cite any research as to an exact ideal amount of fasting time, so I’ll say anything and everything will work in this case: 1.5 hours or 3 hours, overnight if you’ve worked out late. I just don’t go for the high carb PWO meal anymore. Remember,… Read more »
Michelle
3 years 6 months ago

I’ve just started documenting my own experience with IF as I prepare for a physique show. So far I love the results, and will try a 2 hour post-workout fasting window to see if that accelerates fat loss. Thanks for the post!

Michelle
Michelle
7 years 10 months ago

Hi Mark, Love your blogs soo helpful! I’ve been low carbing for only 5 weeks, I’m having between 15-30gms carbs. I have had major blood sugar issues in the past which are improving little by little since switching to low carb. I’m wondering whether fasting after a workout for a person with blood sugar issues is a good idea?

Roelant
Roelant
7 years 10 months ago

Hey Mark,

I had a similar question. If one is already partially ketotic going into a workout, and one works out intensely, say 20-35min (ie. a long-ish crossfit WOD)would blood sugar be a bit “high” right after the workout? since the body will be converting fatty acids to ketones, how will that read on, say, a blood sugar meter for a diabetic?

Mark Sisson
Mark Sisson
7 years 10 months ago
Michelle, you could always go the protein route after your workout. Giving your body a substrate to use for gluconeogensis as needed (and gluconeo burns fats) should address the low glucose issue. As for the follow-up question, I can only speculate as to what a meter might read PWO. Ketosis itself generally causes a drop in glucose and/or gluconeogenesis – not a rise. There are a few variables that will affect this: are we talking type 1 diabetic? (different mechanism), how much glycogen was in the muscles and liver before the workout, how long the subject has been in ketosis,… Read more »
Ashley Moran
7 years 10 months ago

I try to follow alternate-day fasting as much as possible, a 36/12 hour fasting/eating cycle (often more like 40/8). I frequently train on two consecutive days: early afternoon on the fast day and a similar time on the eating day, before breaking the fast mid-afternoon. Not only is this not counter-productive, it possibly even gives me a boost. I really tear into a workout on an empty stomach.

Most people I tell about this have a fit when they realise how long I go without food before training. Some can’t even believe I skip breakfast.

Andrew R
7 years 10 months ago

Thanks Roelant and Mark!

All the Best,

Andrew R

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[…] Growth Hormone Levels Post-Workout Mark Sisson has an excellent post on how to maximize human growth hormone (HGH) levels. The basic steps […]

Scott
Scott
7 years 10 months ago

The best sleep I ever have is midway through my fast, sleep is so good.

Donna
Donna
7 years 10 months ago

Great post Mark,
I enjoyed reading your interview with Andrew.

I’m also a fan of Jack Lalanne all my life, since i was little, i’d watch him on T.V. and exercise with him, it was fun!

Scott,
Fasting causes my best night sleeps, actually get better night sleeps on a day of fast.

Mark,
I more than appreciate this post, you’ve answered alot of my questions i’ve always had on fasting!

Mike OD - IF Life
7 years 10 months ago

Great post. As I say, muscle builds 24/7….well if you give it the correct stimulus of course. Also there might be MORE benefit to pre-workout amino acids in their role for muscle repair vs post workout. Post workout shakes are for people who like to get fatter and call it mass (not muscle) gaining….I did it for many years of my younger life.

Andrew R
7 years 10 months ago

Hey Mike,

Wow, I’m so glad you said that! I’ve been using BCAA’s (powder) pre workout for months now and I’ve really seen the difference!

Thanks bud!

All the Best,

Andrew R

jimmy
jimmy
7 years 10 months ago

With all due respect, I’m a bit disappointed with the article. Where is the evidence (research) to back up these claims? I’m not convinced that fasting after a workout or before one is optimal for muscle retention/building. I mean, anything is possible, but saying that our pre-ancestors sometimes had to do it proves absolutely nothing. Give us some substance, not mere speculation.

trackback
7 years 10 months ago

[…] calories should be counted like pounds, a birthday in canning, Paul recommends a book, post-workout fasting, food companies make false claims (gosh, no, really? shocking), Dr. Eades lays into the […]

Richard Nikoley
7 years 10 months ago
Add me to the list of fasters, not only after a workout (intermittently) but almost always before. 90% plus of my two weekly 30-minute intense sessions are begun at a point where I’ve not eaten for 18-30 hours (I’m still in fat loss mode — I’ll be looking to cut that to every other time). I love working out fasted, and during the time I’ve been doing this my bench press, as one indicator, has gone from around 100 pounds to warm up at 135, then 185, then 205. I’m usually hungry when I begin the workout, but hunger is… Read more »
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[…] for those who are looking to build muscle, but it’s not the only way to get it done, as Mark’s Daily Apple has shown us. Stay tuned because tomorrow we’re going to take a look at Will Smith’s […]

KnoxiaVemiaUnfonse
KnoxiaVemiaUnfonse
7 years 9 months ago

encdxkcjsototkvqwell, hi admin adn people nice forum indeed. how’s life? hope it’s introduce branch 😉

trackback

[…] Dear Mark: Post Workout Fasting […]

ZMH
ZMH
7 years 8 months ago

Mark,

Just curious what your thoughts were on Robb Wolf’s take on post workout nutrition;

http://robbwolf.com/?p=272

It appears that you both have very different thoughts on the matter.

Mark Sisson
7 years 8 months ago

As for PWO nutrition, sometimes I eat and sometimes I don’t. Good reasons for both, I guess, but remember that in PB workouts, you really don’t need to refill glycogen stores the way you do if you are training longer, harder and higher heart-rates. When there’s no need for extar glycogen, there’s no need to eat extra. meanhwile, HGH improves when you DON’T eat PWO.

Joey Lajoie
Joey Lajoie
7 years 6 months ago
Hey Mark, I’m glad I just came upon this article because I have a few theories regarding pwo nutrition and you seem have similar views. 1) Number one is the HGH double whammy. Another theory I have is that while fasting blood is supplied to the brain and muscles, blood is essential to repair of damaged tissues. Now eating a big carb heavy meal would, imo, divert the blood from those damaged muscles and into the digestive system further impairing muscle repair. 2) I have read the six part post over at iflife.com about what happens to your body when… Read more »
Mark Sisson
7 years 6 months ago

Joey, I agree with all three points. Not being a scientist sometimes means you get to think logically and not have to back it up with some made-up science project!!

trackback

[…] and I feel like I eat like a bird. Sure, there are times where I eat a massive meal, like after a workout-fast session or a grueling day, but most of the time I’m just not that hungry. Comments like yours, my own […]

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[…] Post Workout Fasting […]

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[…] of post-workout carbs led me to this excellent post by Mark Sisson, which was followed by this equally interesting post. At this point, a lot research seemed to indicate that PWO carbohydrates were not necessary, maybe […]

trackback

[…] of post-workout carbs led me to this excellent post by Mark Sisson, which was followed by this equally interesting post. At this point, a lot research seemed to indicate that PWO carbohydrates were not necessary, maybe […]

trackback

[…] Mark’s post on post-workout fasting […]

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[…] Mark Sisson on PWO Fasting […]

alfredoe
6 years 7 months ago

I would like to see solid information regarding the HGH production when fasting after a work out.

Regards,
Alfredo E.

Ben
6 years 7 months ago

The link to the interview is dead. Here’s a working url for the interview:
http://gohealthygofit.com/?p=1641

trackback
6 years 7 months ago
[…] Whey protein falls into the 80/20 category. It isn’t strictly Primal (and certainly not paleo) in that it wasn’t available to Grok, but it can be an effective, occasional high-protein meal replacement with most – if not all – of the potential allergens mitigated or negated. It’s an analog, a bit like dairy itself. If you can’t handle any dairy, skip it (or try whey isolate) and take the time to prepare a meal. If you can handle dairy without a problem, a whey protein powder is a pretty good way to shuttle nutrients into your body, especially if you’ve chosen to… Read more »
trackback

[…] Sisson has an excellent post on how to maximize human growth hormone (HGH) levels. The basic steps […]

trackback

[…] Sisson has an excellent post on how to maximize human growth hormone (HGH) levels. The basic steps […]

trackback

[…] often. If you’re going for pure size and strength, fasted workouts and skipped PWO meals may not be the ticket. You’ll burn more fat with the extra GH secretion and existing muscle will […]

Lojasmo
Lojasmo
6 years 2 months ago
trackback

[…] Total time was 16-17 minutes.   An absolute gasser that left me horizontal and panting in the shade after the last flip.  Didn’t break the fast until 2-3 hours later since WODs like this usually suppress the appetite.  That’s another thing about paleo/primal eating – you don’t feel the need to “re-fuel” immediately after exercise.  In fact, waiting a little while can increase hormone release!  […]

trackback

[…] be an effective way to shuttle in protein and glycogen. I don’t do it myself, because I like to fast post-workout (and I don’t like the taste of regular milk) but some people swear by it. This is just […]

Jeff
5 years 10 months ago

The occasional IF does wonders for fat loss.

Phil
Phil
5 years 7 months ago

One thing I wonder about regarding post work out carbs…doesn’t elevated insulin suppress cortisol? How does one factor that in as a mitigator to the catabolic effects of the elevated cortisol? As of now, I still have a banana as part. I have wondered about whether to ditch it or not.

Haluk
Haluk
5 years 2 months ago

Hey Mark,

I read different approaches to preworkout nutrition while fasting. Some say your first meal after fasting should be the preworkout meal while others say the first meal should be post workout meal. What do you think ?

One more thing, right now I follow the traditional 6 small meals per day and do my cardio on empty stomach in the morning. How would you place the cardio if I do IF and if my eating period is between 17.00 – 24.00 *

Thanks

Steve
Steve
4 years 8 months ago

Post-workout nutrition is grossly over-hyped pseudoscience. Scientifically, there is no magic nutrition window for muscle growth, which actually continues 3+ days after each workout. Plus, the body has more than enough protein available to recycle for muscle needs for an hour or two (actually, much longer than that).

The notion of a “magic window” for post-workout nutrition is just based on misunderstanding a small portion of research taken grossly out of context.

Brandon Adams
Brandon Adams
4 years 7 months ago

Hello Mark,

I was wondering, if I were to fast PWO when I did eventually eat does it really matter too much what level of protein I eat? Should I strive for a fast digesting protein as I would PWO or just go with a high quality protein regardless of the pace of digestion? And also after that fasting period are you still a fan of hardly any carbs or none at all?

trackback

[…] in Anytown, USA – but for whatever reason, placing obese patients on extended and short-term fasts became relatively common […]

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[…] I have no desire for it. I might eat later that night, but only if my appetite returns. I’m fasting post-workout only because it doesn’t occur to me to eat, not because I’m following a […]

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