Training for Longevity, Not Weight Loss<\/p>\n
Up until then, I had never thought of the true importance of exercise<\/a>: I\u2019d only thought of it as a means to an end\u2014to lose weight and, ideally, to look better in my clothes. Although it is true that exercise can help on both accounts, Isidro allowed me to see that neither of those are as important as keeping the body\u2019s muscles and mitochondria healthy for as long as possible. \u201cThe mitochondria are like little batteries that produce the energy that impact vitality,\u201d Isidro explained. \u201cWhen the mitochondria work well, we feel strong; when they deteriorate, we feel fatigued. It\u2019s also difficult to burn fat, even when we diet. Fat not only accumulates under the skin but also in organs, viscera, and even in the muscle itself.\u201d<\/p>\n Here, there is no miracle pill\u2014the only \u201cmedicine\u201d proven to improve mitochondrial function is exercise, and especially strength training. Just as a cell phone battery lasts for hours when it\u2019s new but loses its ability to hold a charge, the same thing happens with mitochondria<\/a>\u2014as we age, we may wake up with energy but feel exhausted by mid-morning. Thus, we must keep our mitochondria as healthy as possible.<\/p>\n Fast Twitch Fibers and Slow Twitch Fibers<\/p>\n Within the muscle there are slow twitch fibers and fast twitch fibers\u2014 slow twitch fibers are responsible for prolonged efforts such as walking; fast twitch fibers are essential for power and speed.<\/p>\n