As we age, our body shape changes. We slowly lose muscle and we slowly gain fat. It is a part of life, but once we turn 40, male or female, our muscle mass declines by 1% per year. As a result, our strength decreases by around 3% per year. Studies have shown that older people tend to under consume protein. Their bodies continue to use carbohydrate as the main fuel and their bodies tend to store more fat. Why this all happens is still not clear but scientists have been focussing their attention on our energy-producing structures, called mitochondria. As we age, the number of mitochondria fall, which decreases our ability to generate the energy to power all our chemical reactions in our bodies, including muscle contractions.
New research has shown that muscle strengthening exercises actually refresh the mitochondria. Not surprisingly, increased exercise in older people also slows down muscle loss. Therefore, as we age, we should look towards consuming more protein and making the effort to keep up some level of regular strength-based exercise.