Elderly Challenge - Observation 4

I notice that some elderly like exercising. This is a good thing for them as it helps to keep them fit and strong. Besides from running, I also see some elderly doing Tai Ji to help them physically and mentally. This also helps them to gain more friends and enjoy themselves, rather than staying at home and doing nothing. However, during their exercise, they should not exert themselves or they may hurt themselves slightly or a lot, which may be dangerous, due to their old age.