How Much Is Too Much?
None of this is uncommon, I learned. David Nieman, in the department of health and exercise science at Appalachian State University, years ago abandoned marathons for working on his farm (and says he feels much better now). He says that while immunity goes up when you work out moderately for about an hour, immune function decreases when you work out for more than 90 minutes (a reason marathon runners get sick after a race). The long-term effects of this immune system suppression aren't clear.
As for my fatigue last season, I was probably flirting with overtraining, I concluded after talking with Jack Raglin, who does research in kinesiology and sport psychology at Indiana University. This isn't the same as exercise addiction, where people take multiple classes a day at the gym and compulsively work out. Overtraining syndrome is defined by its symptoms: changes in mood, altered appetite and sleep patterns, perhaps a series of colds, and a decline in performance. It's common in endurance sports or other sports that require intense off-season conditioning. The only way to break the cycle, he says, is to rest. Which is what I did after my disappointing season.
After talking to all these experts, I'll concede that speaking purely of physical health, I long ago reached the point of diminishing returns from my workouts. "I tell everyone to walk vigorously 30 minutes a day," says Paul D. Thompson, a cardiologist at Hartford Hospital in Connecticut. Exercise does raise the odds of a heart attack while you're working out, but if you do it consistently, it cuts your chances of heart problems over the long termand provides a host of other benefits, from staving off obesity to preventing osteoporosis and possibly cancer. Quadrupling or quintupling Thompson's prescription isn't going to similarly increase my chances of better health and, if I'm not careful, may put me at risk for other problems.
That said, there's no way I'm giving up my two-hour runs and six-hour bike rides. Some people climb mountains or meditate to achieve mental and emotional clarity or to cope with stress; I work out for a long time. Instead of drastically reducing my training, which would have the side effect of making me extremely unpleasant to be around, I've decided to make a concerted effort to maintain balance in my life: to occasionally sleep in rather than head to the pool at 6 a.m., to spend an hour with friends or family for every one I spend on my bike, and to generally put my training in the larger perspective of my life. While, of course, still trying to kick ass in my next race. That, I feel in my gut even if I can't prove it with research, is the best exercise routine for me.