Training 4-5x a week is within your control. Winning the lottery is not.
I get up every weekday morning at 5 to 6am to do a spin or group fitness class and lift 1 to 2 times per week Arnold superset style. I'm loving this lifestyle. (I guess the gym being Equinox helps.)
Those in their 80s have nothing but free time. Of course they won't have the energy to train 4-5x a week if they have been sedentary the last half of their life.
I agree with jmull here. In my personal opinion things like intermittent fasting might be a lot more broadly applicable to the elderly than exercising 4x a week or becoming a triathlete.
I get up every weekday morning at 5 to 6am to do a spin or group fitness class and lift 1 to 2 times per week Arnold superset style. I'm loving this lifestyle. (I guess the gym being Equinox helps.)