I was in the gym and I heard a message over the loudspeaker.  “Research has shown that 30 minutes of exercise per day extends a person’s lifespan by 1.1 years.”  Presumably, this was meant to encourage me to keep paying my gym dues stay active. 

Based on this information, however, exercising appears to be a negative sum game. 

Let’s look at the numbers…

If I expect to live another 40 years, then exercising 30 minutes a day will cost me :

 3.5 hours a week
 182 hours a year
 7280 hours over the next 40 years

Let’s make some further assumptions:
 
 I’d like to maximize the amount of time in my WAKING life, and my sole purpose for exercise is to extend my life expectancy.

 Excercising for 7280 waking hours should extend my life by 1.1 years or 9636 hours…ah, but let’s be conservative and say I’ll sleep for 6 hours each night… in that case, I’ll extend my waking life by a mere 7227 hours.  I can extend my waking, non-exercising life by a few days by immediately suspending my workout program and spending that time on the couch watching American Idol.

Furthermore, I value money, and my gym membership costs me roughly $500 a year or $20,000 over the course of 40 years (presuming no rate increases…ha!) Maybe I should wait until I’m 50 and start exercising then.  If I can still add 1.1 years, exercise becomes a positive sum game.

Are you convinced?  I sure hope not!  Exercise provides many additional benefits that maximize the quality of my waking life, but cannot be quantified per se.  This view of exercise as a negative sum game is similar to viewing the forex market as a zero-sum game and not considering the positive externalities that result from the marketplace’s function as a risk transfer mechanism.