When done in moderation--triathletes, are you listening?--mixing up fitness activities such as running, swimming and cycling (and adding a little strength training and stretching to your routine), leads to higher overall fitness without the same muscle groups and joints being pounded every day.
Flexibility - If it's wet outside, move inside, even if it's to get wet in the pool. If that shoulder is complaining, lay off the swimming and cycle instead.
Muscle balance - Different muscle groups get used, which can help joint stability and lessen overuse injuries.
Motivation - Cross training keeps fitness interesting.
Think long term
Athletes work on an arc, says Matt Fitzgerald, a runner, coach and author of "Runner's World Guide to Cross-Training" (Rodale, 2004, $14.95). You can lay the foundation now for any upcoming competitions or big challenges.
Start slowly and build up gradually. Take days off. Do an easy week every few weeks and gradually build up again after a peak event.
"Even if you're in decent shape and decide to start running, the bones and connective tissue in your legs and feet are just not prepared to handle all of that impact," Fitzgerald says.
Through a small-scale healing process, he says, the bones react to the stress by becoming more dense and stiff and better able to absorb the impact.
But if you do too much too soon, the body will break down faster than it can build up.
That's why the period of time between activities is extremely valuable for bones, tendons, muscles and ligaments, says Dr. David Belfie, an orthopedic surgeon at Virginia Mason Medical Center's Sports Medicine Clinic in Seattle.
"The body adapts very, very slowly to stress that is applied to it," says Belfie, who adds that injuries occur more often from exercising too frequently than from exercising too hard.
"Even with cross training, you have to modulate the frequency of your activity."
Running for Beginners
- Get fitted for a good pair of running shoes.
- Start by adding one-minute jogs about every five minutes in a 20- to 30-minute walk, Fitzgerald says. Increase that to one-minute jogs for every two minutes of walking. Keep increasing the duration of the jogging segments over several weeks.
For Experienced Runners
- Vary your workouts so your body will progress by reacting to different demands.
- "If you keep doing the (same) type of workout every day through the year, you're not going to go anywhere," Fitzgerald says.
- Mix up long, slower runs with hill or interval (speed) training.
- Hills: Hill work in running is especially good for making that transition from building a general base of fitness up to the next level because you can get your heart rate and breathing rate up with less impact than running fast on flat ground.
- Intervals: After warming up, start with 20- to 30-second bursts of speed and then jog for a couple of minutes.
Repeat a half a dozen times "but be sensible," Fitzgerald says.