Notice the title of this is not “gaining muscle increases your metabolism”. I titled it this way for a reason! When some people think about “gaining muscle”, they get worried, because not everyone wants to be huge and muscular. Whether you want to put on a lot of muscle or just want to reduce some fat and increase your metabolism, this post is for you. Let me tell you a bit of the science behind metabolism. I’ll write in much more detail in an article for anyone who wants to be a physiology nerd and see all the details later.
You metabolism is what controls how much energy you use each day. The is the sum of your metabolism while you are sitting and doing nothing together with your metabolism during any physical activity. What determines your metabolism? Simply put, it is just bone and muscle. Bone is pretty set for you and you can’t do much to change the size of your bone thanks to genetics. You also have involuntary muscle, which makes up muscles that help with digestion, breathing, and your heart beat. What is left is voluntary muscles. Bone, involuntary muscle, and voluntary muscles are together called lean mass. These are the muscles that you choose to use so that you can move yourself or other things. The smaller these 3 things that make up muscle mass are, the slower your metabolism will be. The problem is, once you are an adult, two out of 3 of these stop growing. Our bone mass and our involuntary muscles are the two that stop growing and developing and maintaining a high metabolism. That leaves voluntary muscles (or skeletal muscle) left as the only thing that can fluctuate.
So, if I want to change my metabolism, then I need to increase the size and/or the density of the skeletal muscle in my body. There are two different ways I can do this. I can either try to make them only stronger, which makes them more dense but not too much bigger, or I can make them bigger, which makes them both more dense and stronger. Whichever you choose, it will develop your skeletal muscle and increase your metabolism so that you use more energy while at rest and during exercise. With proper nutrition, this leads to a great physique and body fat control.
After all this, I hope you are encouraged to do some sort of resistance exercise and not just cardio so that you can develop some strength and see some real, lasting results!