HIIT exercises

Researchers in Australia recruited women who had survived breast cancer and had them undergo a single bout of either resistance training, such as weightlifting, or high-intensity interval training (HIIT), which involves short, intense bursts of exercise followed by short breaks. They found that immediately after one 45-minute resistance training or HIIT routine, participants showed up to 47 percent higher myokines in their blood.

After you turn 50, fitness should be less about training to look a certain way and more about exercising to prevent cardiovascular disease, improve balance, and maintain muscle mass. Your health and well-being are what's most important.