You’ve probably heard this bit of conventional exercise wisdom: you have to pre-fuel so you don't run out of gas during your workout!
But is that always the best advice? Well, if your goal is to lose weight faster, build more muscle, and get in eat-your-heart-out shape for the next time you run into your ex, science says it might be better and even smarter for you to exercise on an empty stomach. Here's how it works:
You'll improve your insulin sensitivity
Insulin is an important hormone in the weight-loss puzzle because it's a critical player in how your body metabolizes sugar. Eating too much sugar is bad for a lot of reasons, one of which is that it can make your body more resistant (or less sensitive) to insulin’s sugar metabolizing effects, which can lead to things like diabetes and weight gain down the line.
This is where exercising on an empty stomach comes in: research shows it can actually help your body become more sensitive to insulin, thus making it easier to burn off the sugar you eat.
You'll boost your growth hormone production
The second effect of fasted exercise is that it boosts growth hormone, which plays a role in your metabolism and helps protect lean muscle. In fact, after a 24-hour fast, men and women experience a 2,000% and 1,300% increase in HGH production, respectively. If your name isn't Peyton Manning, that HGH boost will do wonders for you.