Age should not be the deciding factor when you think about exercise. Many people who led a sedentary life start becoming active post retirement. Over a period of time, health and fitness improve even if you started late. There is the French cyclist who never used to exercise before retirement, but started cycling around town once he started having time to himself, is now going about setting records in cycling at 105 years of age! (https://www.nytimes.com/2017/02/08/well/move/lessons-on-aging-well-from-a-105-year-old-cyclist.html).
More than age, it is persistence (or the lack there of) that determines fitness in the over 60s. It is proven that even with increasing age, fitness does improve with regular exercise. (https://cdn.ampproject.org/c/s/www.washingtonpost.com/amphtml/news/inspired-life/wp/2017/02/03/do-or-decline-an-athletes-age-may-be-less-important-to-performance-than-persistent-practice/).
Please do not discontinue your exercise regimen because of age and do not think you cannot start exercising because you are beyond a certain age!