A Feast/Fast Model for Muscle Growth

Here is a simple framework that offers the potential to build muscle without increasing body fat.  The cycle starts on the day of a planned resistance training session.  It would seem logical that a person should somewhat undereat prior to the exercise session.  This is done for two reasons:

• When an animal or hunter-gatherer runs low on food, this is the logical time when they would begin a new hunt (workout)
• By fasting or eating less prior a workout, this will help increase hunger after the workout, which would then allow for more food intake in this crucial period

After the workout, there is a roughly 24-hour window where most or even all of the calories are going to muscle repair and growth.  With sufficient calories, the muscle repairs itself but does not rebuild.  With a calorie surplus, new muscle mass is created.

I think a shorter post-workout window for muscle growth makes sense from an evolutionary perspective.  If a person undergoes a strenuous hunt/workout, then it would make sense that the body would want to react to this stressor and remodel itself as soon as possible.  This is in case the stressor comes again sooner than later.

If this model is correct, then here is what I think is happening with traditional "bulking" cycles.  A person works out and breaks down muscle tissue.  If they have a calorie surplus in the next 24 hours, they build muscle.  After this, the post-workout window is closed.  If they continue to eat a calorie surplus after this period, they also build muscle, but this is simply muscle built via general overfeeding and part of this overfeeding will go to fat storage.

So in summary, here's the simple model I'm proposing:

• Undereat or fast before a workout
• Resistance train to break down muscle
• Run a calorie surplus during the post-workout window to create new muscle
• Return to normal eating (intake = expenditure) after the 24 hour window
• Net result: muscle gain without fat gain

This would be compared to a traditional bodybuilding model:

• Eat or overeat before a workout
• Resistance train to break down muscle tissue
• Run a calorie surplus during the post-workout window to create new muscle
• Continue to run a calorie surplus after the window has closed
• This overfeeding after the window has closed will lead to both muscle and fat gain
• Net result: muscle gain with fat gain

More to come on this...

Comments

[Chris H]

Some good thoughts here - and in the last couple of posts - Matt. I'll need to think through a bit more when I' got some time later.

One thing I think we still need to remember is the importance of the composition of what you are eating - I think there is more to it than calories you are taking in.

[Matt Metzgar]

Definitely the macronutrient ratio is important. I just haven't gotten around to that part yet.

[Jeff]

I have been doing something similar to what you propose. I fast Monday(~23hrs), Wednesday(~18hrs) and Friday(~23hrs), which are my lifting days. The workout is pretty intense and ~45mins total, followed by a 10-15min walk. I then don't eat for at least an hour and more on Monday and Friday, at which time I eat a lot Paleo style. I had been doing that lifting schedule without the fasting and dropped to ~8.5% body fat. I feel like mixing in the IF that I am getting stronger and leaner, but we will see the next time I have a caliper check.

[Matt Metzgar]

Jeff,

That sounds like great progress. I will be interested to know how the IF works out for you.