The iron pill is good for what ails you, Mangan reminds us:
For example, weightlifting enhances brain function, reverses sarcopenia, and lowers the death rate in cancer survivors. Take this last item, lowering death rate in cancer survivors: garden-variety aerobic exercise had no effect on survival, while resistance training lowered death rates by one third; so at least in this one example, you can see that weight training is a vastly superior form of exercise.
Weightlifting also appears to be superior when it comes to fighting the aging process. Resistance exercise lowers levels of myostatin, which is one of the main ways in which muscle strength and mass are increased, since myostatin negatively regulates muscle strength and mass. Myostatin levels increase with age, which may partially account for loss of muscle mass and frank sarcopenia with aging. Mice that have been genetically engineered to have lower levels of myostatin live about 15% longer than wild-type mice.
Therefore it follows, assuming that the physiology of mice and humans are directly comparable in this regard, that lowering myostatin levels through weightlifting should increase lifespan. (And, as previously noted, branched chain amino acids, creatine, and polyphenols from chocolate and tea also lower myostatin.)