The combination of fasting and exercise triggers an amazing rejuvenation and detoxification process, far beyond what exercise and fasting offer by themselves. In other words, fasting and exercise, when joined, enhance the benefits of one another.
You can assume that all the benefits to be had from exercising are increased when you exercise in a fasted state, such as an increase in the following:
Cellular stress response (to protect us against illness and aging)
Fat burning (lipolysis)
Insulin sensitivity (making it easier to build more lean muscle)
Muscle tissue repair
Neurogenesis (the birth of new brain cells)
The reverse is also true, meaning that the benefits to be had from fasting are increased when you add in exercise. You can look at it from either angle. The body responds to negatives positively. Hardship in the form of fasting and exercise is a trigger for growth. Without adversity, prowess fades away.
And so you may be wondering, what is the best way you can combine fasting and exercise? It largely depends on what sort of fasting protocol you choose to follow. Exercise is best added toward the end of your fasting period because exercise in a fasted state plows fertile ground for muscle growth and rejuvenation.
To really kick-start the muscle-building process, you need to eat within the window of opportunity, the 30 to 60 minutes after your workout, which is when your muscles are most receptive to nutrients and will most effectively utilize these nutrients to build and rejuvenate muscle tissue.
In other words, when your muscles are hungry, they have priority. During this window, you should have your largest meal, because the fuel you take in, so long as you don't overdo it, will go toward replenishing muscle glycogen and repairing muscle tissue, instead of being stored as body fat.
All these benefits we discuss here come from short and intense bouts of exercise, such as heavy strength training, power training, speed training, or metabolic conditioning.
