Interval training is the way to go. It’s never too late to start an exercise program.
https://mobile.nytimes.com/2017/03/23/well/move/the-best-exercise-for-aging-muscles.html?mc=aud_dev&mcid=keywee&mccr=dommob&kwp_0=367955&kwp_4=1372898&kwp_1=605799&_r=0&referer=http%3A%2F%2Fm.facebook.com%2F
