Fasted Workouts: When They’re More Effective (and How I Incorporate Them)

Fasted workouts are a controversial topic in the fitness world. To some, the idea of working out without “carbing up” or doing the pre-workout protein shake is unthinkable. Won’t my performance suffer? Won’t my muscles shrink? Won’t my body think I’m in the middle of some horrible famine and go into starvation mode? To others, fasted workouts are sacred tools, the perfect antidote to modern decrepitude. When I train in a fasted state, I can will my adipocytes to release fatty acids and feel the heat as they burn, hear the barely audible *pop* of muscle satellite cells replicating and proliferating, and see visions of my future physique through my gaping third eye.  Where does the truth lie? Let’s look…. To begin with, the evolutionary argument—the Grok logic—for fasted workouts is extremely appealing and intuitive. Humans did not evolve with access to 24-7 fast food restaurants, grocery stores containing hundreds of millions of calories, and food supplies so ample that we often throw out half of it before we’re able to eat it. If paleolithic humans wanted to eat, they had to hunt or gather something—both of which require the expenditure of caloric energy—often on an empty stomach. In fact, these “workouts” for hunter-gatherers probably occurred more often than not in a fasted state. This doesn’t mean that fasted workouts are ideal or optimal for health, performance, and fat loss. It does suggest that humans have the capacity for working out in a fasted state without falling apart or losing all the benefits normally associated with exercise. The question is if fasted workouts offer any special advantages. Today, I’m going to dig into the literature to explore the most frequent questions and claims about fasted workouts and arrive as close to the truth as we can. Are Fasted Workouts Good or Bad for Muscle Gain? Let’s take a look. One common argument is that since you’re not eating, which already “stresses” the muscles and deprives them of structural substrate, stressing the muscle with exercise causes it to “melt away.” This is overly simplistic, if attractive. For one, that first bit is wrong. Reasonable durations of fasting don’t cause muscle loss. In fact, you can do a few days of fasting without incurring any significant muscle loss. The ketones generated during the fast have protein-sparing effects, and the fasting-induced spike in growth hormone also spares muscle from breakdown. There was even a study where blocking growth hormone with a GH blocker caused fasting people to lose 50% more muscle than fasters who didn’t get the blocker. For two, strength training itself is a powerful signal to your body that your muscles are essential tissues vital to your survival. Your body generally tries to avoid burning through essential tissues. Lifting also increases growth hormone. Paired with the fasting-induced GH boost, your muscles will be in good standing. Okay, so fasted workouts don’t appear to be bad for gains. Are they good? Fasted training augments the anabolic response—the ability of muscles to take up protein … Continue reading Fasted Workouts: When They’re More Effective (and How I Incorporate Them)