Timing fasting and refeeds for maximum strength and muscle gains


(Dustin Ewers) #1

I know that fasting create a spike in human growth hormone, but I’m not sure about the timing. I’ve heard the amount of HGH increases after 14 hours, but I could be wrong. Additionally, insulin is anabolic, so ideally you’d work a controlled insulin spike (from protein, not carbs) into the mix.

What would the ideal fasting regimen be for maximizing strength and hypertrophy?

Here are some theories…

  1. Muscles are repaired after exercise, so workout, eat some protein, and then fast for the next 24 hours. This would give you the protein to rebuild the muscles, but would also have increased HGH during the repair phase.

  2. Fast pre-workout to maximize HGH during your lifts, and then eat afterwards. I’m not sure how fast HGH is cleared from the blood, but you might be able to spike HGH and insulin at the same time.

Things to think about:

  • When do you get the maximum muscle repair post exercise? (presumably in the sleep phase after your workout)
  • What’s the timing on HGH spikes during fasting?
  • Does increasing HGH in during the recovery phase increase hypertrophy?
  • Do we need to have nutrients (specifically protein) available to maximize muscle growth?

(IDM Educator) #2

I’m totally actively looking for the specific science on this right now because I really would like to know myself!

(Mark Rhodes) #3

When I fast I finish with working out with heavy compound movements. This normally happens days 3-6 so I get elevated HGH I break my fast with a HWC and Almond Milk shake with BCAA, EAA, collagen, glycine, glutamine and carnitine. My hope is to use the insulin spike to jam my muscles full of the goodies they need.

Seems to work.

(Todd Allen) #4

Growth hormone is counter regulatory to insulin as it raises blood sugar while insulin lowers blood sugar. High blood sugar stimulates insulin release and blocks the release of growth hormone. Low blood sugar stimulates growth hormone release with the peak in the low 60s mg/dl, but below that cortisol is stimulated which raises blood sugar more strongly by promoting the breakdown of muscle to release amino acids to support a higher rate of gluconeogenesis.

I think ones approach is impacted by their degree of insulin sensitivity/resistance. If one is highly insulin sensitive one can incorporate significant carbs in the post workout refeed and get the anabolic effects of insulin which should also keep blood sugar from rising much and if all goes well your blood sugar should be in the sweet spot near the end of your night’s sleep when GH normally peaks. With diminished insulin sensitivity one probably will do better skipping going for a big insulin response with carbs and instead just trying to keep their blood sugar in a low normal range to make the most of GH. If one is highly insulin resistant they are somewhat screwed as insulin resistance resists the anabolic effects of insulin and fasted blood sugar tends to remain high limiting GH. Worse GH works in large part through stimulating IGF (insulin like growth factors) and these are partially dependent on insulin receptors so insulin resistance diminishes their effectiveness a little too.

Eating keto and especially fasting lowers blood sugar and insulin and enhances the sensitivity of insulin receptors to insulin although severe insulin resistance is a loss of insulin receptors and not just their sensitivity. Consuming protein, especially that rich in leucine such as whey, can stimulate both insulin and counter regulatory hormones such as glucagon and GH. I find that when I’m fasted and very glycogen depleted consuming whey alone can cause my blood sugar to drop quite low and then rebound higher later. Consuming it with a modest amount of carbs, a few strawberries works well for me, keeps the blood sugar swings small - I shoot for staying withing +/- 10 mg/dl, typically starting from the high 60s to low 70s when fasted. If I consume too much carbs with the protein, instead of the initial drop in blood sugar I’ll get a rise and it doesn’t take a lot of carbs probably because my muscles are still fairly insulin resistant.

All of which is a long winded way of saying you probably need to experiment and try to find what works best for you as it may not be the same as it is for the pro body builder who shares the secrets of their success.

(Dustin Ewers) #5

That’s good stuff. Thanks for the info drop.

Based on that I’m seeing zero reason for someone who’s pursuing the keto lifestyle to eat carbs as a way to spike insulin post workout. I was thinking whey is the way to go (see what I did there) for post workout, though that’s not for everyone.

I also read some stuff from the Mayo clinic about HGH not necessarily being the magic muscle growth serum, but the article was referring to exogenous HGH.

(Todd Allen) #6

It seems nearly magical, but more like black magic.

Bodybuilders and other athletes who use exogenous GH can get great results for a while but it often leads to trouble. It aggravates insulin resistance which can progress to diabetes even when one is lean and muscular. With exogenous GH one can end up with the unnatural state of having high GH and high insulin at the same time which causes not just muscle growth but growth of bones and organs resulting in many health problems. Heavy users die young from heart failure or aggressive cancer.

(Mark Rhodes) #7

Todd help me out if you can. If I am fasting and my normal BG range is 85-90 and my fasted state is anywhere between 40 & 70 then I can gage HGH based on BG? So that if I drop below 55-60 I am likely no longer producing HGH? Conversely if my BG is, say, 65 mg/dl this would be a sweet spot to workout and recover in?

(Dustin Ewers) #8

With exogenous GH one can end up with the unnatural state of having high GH and high insulin at the same time which causes not just muscle growth but growth of bones and organs resulting in many health problems. Heavy users die young from heart failure or aggressive cancer.

Yeah… not really interested in juicing my way to an early death. Just trying to optimize strength gains within my current dietary framework.

(Melissa) #9

Aren’t you concerned about the large spike in visceral fat that happened in only two months?

(Mark Rhodes) #10

No. That is not a direct reading and is an approximation. Same with LBM. Since the machine is calibrated for bone and fat, everything else must be LEAN. All within the margin of error for a dxa. That and February’s scan went back to 1.0.

(Todd Allen) #11

I believe ~65 mg/dl blood glucose is the likely sweet spot for maximizing the ratio of growth hormone to cortisol though I need to find the paper with that result. I think it was on healthy college students and it probably doesn’t represent perfectly what happens in the elderly, obese, diabetic, etc.

Glucagon is the primary fast acting hormone to raise blood sugar, primarily by stimulating the liver to dump glycogen. Epinephrine also is a fast acting hormone mainly triggered by acute stress. As the liver glycogen becomes depleted there is a shift to slower acting hormones, growth hormone and cortisol. Cortisol is also a stress hormone and if chronic stress is high you will have a lot of cortisol even at higher blood sugar levels and probably keeping blood sugar from dropping into the sweet spot for GH. In the absence of stress GH kicks in more strongly than cortisol at first as blood sugar becomes mildly low. GH is catabolic for fat stimulating release of fatty acids supporting a low level of gluconeogenesis, but GH is anabolic with respect to protein and it limits access to amino acids which support a much faster rate of gluconeogenesis. As blood sugar drops lower there is still GH but cortisol starts ramping up. Cortisol promotes the break down of protein, especially muscle, to maximize gluconeogenesis and keep blood sugar from dropping critically low.

So ideally in a weight loss phase one wants relatively stable, low normal blood sugar, say 65 to 75 mg/dl through the day such that overnight GH will kick in robustly without getting swamped in cortisol. At dawn cortisol naturally ramps up to kick start our day with a little more energy and my goal is trying to maximize the ratio of GH to cortisol to stay more anabolic. Something I recently started playing with is measuring my blood sugar whenever I wake up at night to pee and first thing in the morning. I’ve been mixing up a little BCAAs plus some whey, glycine, cinnamon and stevia for palatibility and drinking it when I take my blood sugar. I don’t consistently wake at night, sometimes waking early or late and recently have often been sleeping through til dawn when not sick all of which makes it hard to sort out my response and optimize the result. If only it were cheap and easy to do continuous glucose monitoring - and then maybe add a computer controlled IV drip…

(Mark Rhodes) #12

Great information. If you find the links-please? I just checked mine at 40 hrs fasted 64.8 mg/dl so right on target for my afternoon lift! Although I do think I have slight cortisol issues I do not think they are too great. Although I work a stressful job I rather enjoy the pace and rarely if ever take that stuff home in negative ways. My home life is also pretty good as well as practice yoga and vipassana meditation… So I think any cortisol issues are the kind I want to have.

Thanks @brownfat

(Todd Allen) #13

Have you ever tracked your exercise induced swings of blood glucose? If you want to maximize anabolism you might consider a few grams of BCAAs and/or whey, maybe even a tiny bit of carbs, for the workouts while checking that you are not increasing the glucose swings and hopefully reducing them in duration if not amplitude.

(Mark Rhodes) #14

I haven’t except those times I have I have used exercise to raise the BG as I thought initially it could be too low 38 mg/dl and afterwards I could get it back into the 50’s. Currently I try to end a fast with exercise followed by BCAA, EAA, Glutamine, Glycine & Carnitine in HWC & Almond Milk. It does seem to help.

I normally only have HWC in the morning thru late afternoon. It does raise my BG but besides the point. Most of my eating without trying is between 4 & 9 weekdays. With that in mind, I have been tracking GKI and made a concentrated effort in February to try to keep it below 5 using measurements by eliminating HWC. My measures then are 2 hours after waking and sometime in the afternoon.

GKI 10_24_2017 to 04_24_2018.pdf (21.8 KB)

(Troy) #15

Im not sure on the exact video(s)
But thomas delauer on YT has some info this ( HGH, fasting and eating windows )
I am just not Sure on the exact one right now

I am No help really I guess :cry:
I need more HGH, to go search :smile:

(charlie3) #16

Wow, you guys are orbiting way farther out than I ever will. Once upon a time I was quite the serious (drug free) lifting and fitness buff. Now I’m back. My goals arre the same as my younger days but priorities are changed. I’m an older guy now, health markers come first. A few things are new for me. I’m getting better results lifting less agressively than back in the day and keto may be lets me grow some muscle and stay lean, something I just could never quite do back in the misguided high carb days.

So here’s my N=1 that I haven’t seen discussed anywhere. The chart below, generated from Cronometer shows my net calories for the previous week up to yesterday. The green bars above the base line represent excess calores consumed and the green bar below the base line, represents a fasting day and equals BMR + steps + a steady state cardio session. The fasting day deficit calories equals the surplus days added together. I lifted today and was noticably stronger than the previous workout. (I’m doing 3 whole body workouts per week) I’m hoping this pattern will feed muscle hypertrophy with extra calories for 6 days and any added fat is burned off on the 36 hour fasting day.


One of the things I’ve picked up on in this more modern era iis that the body routinely treats muscle as a warehouse of aminio acids that can be used for higher priority repaiirs and maintenance as needed. I suppose that’s the rationale for nutirent timing and excess protien intake. I suspect that with exercise the body gets better at utilizing amino acids regardless of the source the same as it gets better at burning fat from various sources if we encourage that. A larger warehouse of readily available amino acids in the form of muscle is desirable for a number of reasons. For reference the net calories above base line add up to about 2000 and the fast day deficit is also 2,000.

I’m not going to get silly with supliments or nutrient timing or hormone manipulation. I want to be leaner than I could ever manage back in the day and accuent that with a nice physique.


I don’t know how (or if) this information may play into the discussion…but Time Restricted Eating interests me. It seems like there is some science indicating muscle hypertrophy is possible merely by taking NOTHING BUT WATER–ie–not even coffee, tea, and etc outside of your feeding window.

Watch this video and see that there is supposedly a subtle difference between Intermittent Fasting, and Time Restricted Eating. And that the difference was shown to be important in lab rodents.


(Adrian ) #18

Do you think I’m shooting myself in the foot (as far as muscle is concerned) by doing Keto as a highly insulin sensitive guy?
Metabollicaly, I’m very healthy. I handle carbs great from this point of view. However, I don’t digest them well.

(Todd Allen) #19

Possibly. But probably not or at least not severely. Elite strength competitors seem to do better with more carbohydrates while elite body builders pursuing very low body fat seem to do better with aggressive carb restriction at least during cutting phases.

You could check out ketogains for muscle building while keto. Those with good insulin sensitivity appear to have more options. Many use targeted carbs to good effect and others like Shawn Baker get good results while super low carb and rather high protein. Those of us struggling with insulin resistance and/or excessive body fat can easily have trouble overdoing carbs and some find they need to moderate protein too for best results.

If you are tracking your results try various approaches for a few weeks to a few months each and you should get a sense of what works best for you. If you can’t perceive much difference it probably doesn’t matter much.

(Chris - carnivoremuscle.com) #20

In reference to now year old OP, hgh is not anabolic by any means. Growth hormone does not increase skeletal muscle mass at all. That’s why bodybuilders use testosterone and other anabolic hormones in greater volume than gh.

Fasting is catabolic.