“If you’ve never lifted weights in your life — and many people haven’t — why should you start now? The answer is simple: Muscle tissue, bone density, and strength all dwindle over the years. So, too, does muscle power. These changes open the door to accidents and injuries that can compromise your ability to lead an independent, active life. Strength training is the most effective way to slow and possibly reverse much of this decline.
Having smaller, weaker muscles doesn’t just change the way people look or move. Muscle loss affects the body in many ways. Strong muscles pluck oxygen and nutrients from the blood much more efficiently than weak ones. That means any activity requires less cardiac work and puts less strain on your heart. Strong muscles are better at sopping up sugar in the blood and helping the body stay sensitive to insulin (which helps cells remove sugar from the blood). In these ways, strong muscles can help keep blood sugar levels in check, which in turn helps prevent or control type 2 diabetes and is good for the heart. Strong muscles also enhance weight control.
On the other hand, weak muscles hasten the loss of independence as everyday activities — such as walking, cleaning, shopping, and even dressing — become more difficult. They also make it harder to balance your body properly when moving or even standing still, or to catch yourself if you trip. The loss of power compounds this. Perhaps it’s not so surprising that, by age 65, one in three people reports falls. Because bones also weaken over time, one out of every 20 of these falls ends in fracture, usually of the hip, wrist, or leg. The good news is that the risk of these problems can be reduced by an exercise and fitness routine that includes strength training.”
HealthBeat—Harvard Medical School Newsletter (May 2012)