People who stay single, or become single again by divorce, may be somewhat more physically fit than those in wedded bliss, a new study suggests. The research, which followed nearly 8,900 adults over several years, found that both men and women who got married during that time tended to experience a dip in cardiovascular fitness, as measured by treadmill tests. In contrast, men who got divorced during the study saw a modest increase in their fitness levels. The findings, reported in the American Journal of Epidemiology, do not prove that a change in marital status directly causes the change in fitness — for better or worse. Still, researchers say the results support the notion that once people are married and, presumably, off the dating market, they tend to let themselves go a bit. But if they remain single or get divorced, they have more incentive to get in shape. That's not to say that there's a huge fitness chasm between singles and married couples...