Some athletes would rather run on tacks or pedal through freezing rain than miss a day of training -- but they'd probably do themselves a favor if they exercised less.
Hard-core athletes can have trouble accepting the fact that giving their bodies time to recover after a hard workout will actually enhance their performance, coaches and trainers say.
"These people think they will lose fitness if they don't work out hard every day," says Paul Huddle, a triathlete coach in San Diego. "They see missing a day as a setback." Other athletes don't feel virtuous unless their workouts produce exhaustion.
However, Huddle adds, "if you go hard every day, you'll never do your best." He and other experts recommend a day or two off each week for those who exercise regularly.
The reason lies in muscle science. When you work out, you cause micro-tears in the muscle. As muscles mend, they become stronger than before.
If you tear those muscles again before they've fully recovered, you won't achieve your maximum potential, says Scott Trappe, director of the Human Performance Lab at Ball State University in Muncie, Ind.
Since 1965, researchers there have been studying how athletes' cardiovascular and musculoskeletal systems adapt to performance.
Anyone who exercises daily, even if it's only 30 minutes on the treadmill, will do better with a day off, Trappe says. "Not getting enough recovery time is like not getting enough sleep," he adds. "You need a break from exercise so your body can do its housekeeping."
Good performance, Trappe says, boils down to equal parts of training, nutrition and rest.
"For most committed athletes, putting in the time and energy to train and eating right is not an issue," he adds. "What is an issue is getting enough rest."
In a study, the results of which will be presented this spring at the American College of Sports Medicine's annual meeting, Trappe and his colleagues tracked 21 novice runners training for a marathon. They took biopsies of the participants' muscles before training; 13 weeks later, at the peak of their workout regimens; and three weeks after that, following a tapering in the duration and intensity of training.
The athletes showed the most improvement in strength and power in the final tests, according to Trappe.
A similar study also conducted at the Ball State lab, published in 2001 in Medicine & Science in Sports & Exercise, the journal of the American College of Sports Medicine, found that swimmers who incorporated tapering and recovery into their workouts showed an increase in strength, speed and power during those phases of training.
In a third study, published in 2002 in the Journal of Strength and Conditioning Research, researchers from the University of Connecticut and elsewhere tested the leg strength and vertical-jump height of 10 elite male runners, measuring them before they ran a 10-kilometer race, immediately after they ran it at maximum effort and 48 hours after the competition. Forty-eight hours after the race, the runners still had not recovered the strength they had just before it.
Still, many hard-core athletes find it impossible to slow down. Trappe uses as an example the athlete who works hard every day, then is forced to take a week or more off because of injury or illness. Often, the athlete will feel bionic when returning to play, Trappe says. "Some will recognize that new surge of energy and power as the benefit of the time off," he says. "Others write it off as a fluke and pick up their old bad patterns."
Michael Collins, an Irvine-based swim and triathlete coach, says a good workout regimen includes days when you push yourself, days when you work to maintain and days when you recover. "The aim is not to be trashed after every practice. If you hammer yourself all the time, you can't give your supreme effort when you need it," he says. "I can't beat it into athletes enough: It's better to be 20% undertrained than 15% overtrained."
Another thing that many athletes don't understand, Trappe says, is that it takes 30 to 60 days for the results of a workout to show up in muscles.
Muscles need that much time to build and assemble new proteins, Trappe says. In other words, you won't see the affects of today's workout for a month or two -- assuming you keep working out moderately to maintain a fitness level and take days off occasionally.
Before participating in this year's New York City Marathon, Trappe, a competitive marathoner, took his last big training run of 23 miles five weeks before the event. He tapered training from there, cutting intensity and duration by about 20% each week, and continued to take two days off a week.
"The thinking is: You work out hard now, taper training for several weeks and hope to get it in your legs in time for the big event," he says.