To prove a point once, fitness trainer Thomas Holland did a little experiment.
"I had one client who loves weights and body work, jumping jacks and push-ups and all that stuff," says Holland, who works at a Richardson, Texas, gym. "I have another who runs. I made them come into a room and gave them the same workout. The runner who thought she was in outstanding shape almost threw up before she was finished."
By the same token, could the gym hound have been able to run a mile or two? Or a die-hard cyclist jump into a pool and swim a half-mile for the first time? Probably with the same amount of finesse as a swimmer would show in her first yoga class.
"Complementary exercises, in my mind, are mandatory," Holland says. "Exercise ought to be a situation of balance where you don't get carried away with just one."
Doing any sort of exercise is commendable, and infinitely better than never breaking a sweat or lifting nothing heavier than a Frito. If you stick with one form of exercise, though, other parts of your body — upper, lower, core — will suffer.
Sam Cole learned that lesson when his only exercise was running and he developed issues with his iliotibial (IT) band. From everything he read, he says, "they were caused by not having a strong enough core."
He started going to hot-yoga classes. When they became too expensive, he joined a less costly gym, and now he participates in a fast-moving body pump class. The high-intensity, low-weight workout twice a week has helped his running, he says. He doesn't get as tired. Nor do his shoulders slump as they used to do.
"You're missing half the equation if all you do is run," he says.
Nancy DiMarco of Texas Woman's University says we should exercise the same way we eat — keeping variety and moderation in mind.
"Doing so will train all the muscles in our body, help strengthen us, and help us maintain independence for a long time," says DiMarco, professor of nutrition and food sciences at TWU and director of the Institute for Women's Health.
"So many of the guys in the gym are strong but have no endurance," she says. "Runners are very purposeful. When they want to run, they want to run. They don't mess with this other stuff. But to be well-rounded, to be fit, you need to focus on other areas because they are just as important."
Those areas include cardio-respiratory (swimming, Zumba, walking); resistance training (free weights, machines, medicine balls); flexibility (stretching and range of motion); and neuromuscular (tai chi, yoga).
"Interesting new studies show cyclists losing a lot of bone density because they don't have that impact with the ground like runners do," says Gina Garcia, assistant director of fitness at Southern Methodist University in Dallas. "Cyclists should do impact training as well as strength."
Strength training benefits everyone, experts agree. For swimmers, "you have to have great muscle mass to propel your body fast through the water," DiMarco says.
Garcia says some people get addicted to strength training. Although beneficial for your bones, students at the fitness center tend to be more interested in how toned it makes them look.
Holland remembers seeing a man at his workout facility who was late for a training session.
"He was running up the stairs, and I thought he was going to have a heart attack," he says. "But oh, yeah, he looked really good."
Although exercise is inherently good, limiting it to one type — cardiovascular or strength, for example — will also limit benefits. Here are suggestions from experts to have a more well-rounded, and thus healthier, workout routine.
"They say, 'What do I need yoga for?' But I've had more people come out of it and they say running is so much easier. They're not fighting tightness in their glutes or quads."
You don't have to go to a gym, says TWU's Nancy DiMarco. "Use free weights while watching TV or between loads of laundry."
Tyler Herrin, certified strength and conditioning specialist at Sweat, trained for a half marathon a year or so ago. He did nothing but run, to which he attributes the knee injury that thwarted his training.
"I could almost certainly say if I had done some sort of resistance training along with running that I could have prevented that injury," says Herrin, 33.
We asked him for tips on how athletes in one sport can benefit from incorporating another into their workout. Here's what he said:
If you're a runner …
You need to: Do strength and resistance training.
How? By adding basic exercises like squats and traveling lunges, and working quads as well as ligaments and tendons around the knees. Plus, core exercises will strengthen your abs, lower back and hips.
Why? To help manage posture, strengthen bones and help improve performance.
If you're a yogi …
You need to: Strength train.
How? By adding resistance exercises using weights, elastic bands or machines in a gym.
Why? To allow you to become stronger and hold poses for longer periods of time.
If you're a swimmer …
You need to: Get out of the pool and do dry-land training.
How? By doing such weight-bearing workouts as running, jumping, rowing, stair climbing. "Core strength, upper-body strength is key," Herrin says.
Why? They'll help increase your bone density as well as build up endurance, "which will help in the pool."
If you're a weightlifter …
You need to: Incorporate a cardiovascular routine; increase flexibility.
How? Add some running or swimming. Or take a yoga class.
Why? "Just doing weights won't strengthen your cardiovascular or respiratory system," he says. "Yoga is beneficial for flexibility and respiratory strength."