I often read that when exercising the body breaks down protein. What is that mean exactly and why does it happen? How can it be minimized if that makes sense?
I was just thinking if it is related to making energy out of protein. So, if we eat high carb and fill up our glycogen stores, can it prevent or minimize this protein breakdown process? Or this is something completely unrelated? :)
The body needs to break down proteins consumed in the form of food into amino acids in order to absorb and use them. The body uses these amino acids to either assemble new proteins for direct use in the body or to convert them into various other compounds. Protein breakdown also occurs in the body's tissues/organs/etc as part of a natural turnover process where old cells are replaced with new ones.
I see no reason why you would want to minimize or prevent either one of those processes. Both are natural and necessary.
"protein breakdown" suggests me that your body breaks down the protein in your muscle. And so you lose muscle mass. This is what I thought at least. And then after exercise the body needs to fix it by synthetizing proteins. I may be totally confused about this :) So I was just thinking if we could minimize losing muscle proteins that would be nice.
Yes, muscles are one place in which protein breakdown occurs, along with pretty much every other tissue in the body at varying rates. As part of this breakdown process, damaged (muscle) cells are replaced by new ones. This is needed to maintain everything in working order.
Simply put, whether you gain or lose muscle mass from protein breakdown depends on how the rate of muscle protein breakdown compares with the rate muscle protein synthesis. Some of the factors determining these rates are age, exercise, levels of various hormones and availablity of amino acids.