As you enter your 40s and 50s, how you lose weight and the way you exercise is likely to change. During this time, your body becomes more prone to aches and pains and your hormones shift. Men may experience decreased testosterone levels, and the hormones in women that regulate insulin may become less effective. With these changes your bone mass, strength, and muscle mass may gradually decrease as well. However, that doesn’t mean that you can’t keep up a healthy lifestyle. Men and women in their 40s and 50s should incorporate more protein into their diets and resistan