The Washington Post examines whether it makes sense to exercise today in order to live longer tomorrow.
If you pay attention only to life expectancy, comparing time to exercise (and shower) vs time gained, then yes:
So this means the walking option costs you about 49 days of your life. If the benefit is 1.3 to 1.5 years of life expectancy, you’ve got yourself a bargain….So an investment of 0.5 years in intensive exercise buys you about 1.5 years of discounted future life. Sorry folks, that’s still a bargain.
There are other reasons, as well. You’re likely to have fewer years of bad health. After grumbling the first two weeks about how “this is good for me, this is good for me”, one’s outlook shows a noticeable improvement over pre-exercise days. If this change in behavior leads to reduced fossil fuel use, you can add smugness about what you are doing for the environment as another perk.
So if your first calculation shows that you don’t have time to exercise, recalculate!