If you want to age gracefully and comfortably, you need to prepare. After the age of 50, our lean muscle mass starts to shrink by 1 to 2 percent every year. Over time, that muscle loss increases our risk of injury from falls and accidents, and it can seriously reduce our independence. What if you could reclaim your strength, balance, and energy faster than you ever thought possible? What if you had a field-tested approach to exercise...