HEART BURN
Attention, off-the-couch marathoners: The journal Circulation reports that running less than 35 miles per week for the three months before the race not only will leave you struggling to finish; it can also cause cardiac dysfunction for up to a month post-race. The temporary weakness isn't serious for healthy hearts but could compromise athletes predisposed to cardiac trouble. Per the study, aim for at least 45 miles a week.

METAL IN YOUR PEDAL
Scientists have discovered another "performance-enhancing" effect of Viagra: It can help athletes ataltitude. A study published in the June issue of the Journal of Applied Physiology found that cyclists who popped sildenafil (Viagra's active ingredient) before a time trial at 12,700 feet cut their times by 15 percent, on average. Careful with the Spandex.

HIP CHECK
For the nearly 4oo,ooo Americans who receive hip replacements annually, the surgery used to mean the end of action sports. But last spring the FDA approved a new approach. Rather than inserting an artificial ball-and-socket, the procedure, called hip resurfacing, covers the top of the worn-out femur ball with a metal cap—leaving recipients with a more mobile joint and a far more active lifestyle.

GENDER BENDER
Men who enjoy an alcoholic drink seven times per week lower their heart-disease risk by 41 percent, but women need imbibe only once a week to get a similar benefit, according to a recent study in the British Medical Journal. Cheers, gents!