Have you ever wondered why bodybuilders eat so much? Or why sprinters are always shredded? Or how Michael Phelps could eat pounds of pasta and cartons of ice cream daily? If you haven't, that's fine. As a coach, and someone who has been obsessed with the human body and it's capabilities for over a decade, I found it to be perplexing how lean people always ate so much with seemingly no negative effect.
That's when I heard the line from trainer Jen Widerstrom (famous for being a Biggest Loser trainer), "Muscle pays for the party." To this date, it's been the most simple way to explain the role of muscle in our everyday lives.
Muscle serves a primary purpose: to create the movements that allow us to execute daily tasks. Due to the different types of muscle fibers, we are able to move slowly for long durations of time, or move quickly in short bursts of power and speed. This primary function, however, has some crucial considerations for our daily lives in regards to how we eat. Because muscle is metabolic.
To create motion, muscles have to have access to energy, which is usually measured in kilocalories. Kilocalories, are what most people refer to as calories, and for purposes of clarity will be how I refer to it (because kilo- just means 1,000). So to create motion, muscles use calories.
Now, depending on the muscle fiber type, a muscle will use more calories than others. Slow twitch muscle fibers, due to their smaller size and efficiency in how they create movement, utilize less calories on a daily basis than fast twitch muscle fibers. Fast twitch fibers (both Type 2A and Type 2X), take up a greater amount of total space and are far more inefficient in how much energy they use. Therefore, fast twitch fibers take far more calories than slow twitch fibers do. Slow twitch fibers, however, cannot create as strong or forceful movements that can be useful in everyday life such as carrying or moving objects. Knowing this can be very beneficial to how we approach training.
It's often the misconception that to lose weight or get in shape we must take to the treadmill, stair stepper, or the elliptical. While they have great benefit to our heart health, they do less for burning fat that we think. Those activities may elevate the heart rate, but they are carried out by slow twitch muscle fibers and are relatively inefficient at burning calories. This is where weight training comes into play. Where muscle pays for the party.
Because weight training relies heavily on quick and powerful muscle contractions, it develops fast twitch muscle fibers. The same would go for sprinting. So by creating muscle, we also create the demand for more calories. This can be very beneficial for changing your body composition, because if you keep your eating the same you will end up utilizing fat stores as an energy supply. If you're trying to build muscle or put on weight, it can also help by creating a demand for more food to be consumed.
Now, you may be thinking, "this doesn't apply to me." But in reality it does. Do you like to go out to eat? Do you want to dip into that carton of ice cream guilt free? When we build muscle, we get a little bit more of that freedom. Because muscle pays for that caloric intake a bit more than a treadmill does. This is not to say that you should pig out and eat everything that comes your way, but it is to point to something that some may not realize. That building muscle is what allows us to burn more calories, and to perform more of the daily activities that we enjoy doing.