I have previously argued that if you are committed to an ethic of altruism, you have reason to care about your physical fitness (see Why Be Fit? – Altruism). Here’s a summary of that argument in its simplest form, with direct links to articles in support the premises:
1. If you want to save lives, become a banker (or other high-earning professional), because the more money you earn, the more you can give to life-saving causes (Young, smart and want to save lives? Become a banker, says philosopher).
2. If you want to earn more money, exercise at least three hours per week, since those who do so earn 9% more than those who don’t (One More Reason to Hit the Gym: You’ll Make More Money at Work).
3. Therefore, if you want to save lives, exercise at least three hours per week.