Cross-Training: Giving Yourself a Whole-Body Workout
Bryant Stamford, PhDTHE PHYSICIAN AND SPORTSMEDICINE - VOL 24 - NO. 9 - SEPTEMBER 96
If your browser does not support tables click here.
Exercise can provide a total-body tune-up. It can strengthen the heart, bones, muscles, and joints. It can enhance cardiovascular (heart-related) fitness, build muscle, reduce body fat, and aid in flexibility. But to see all these gains, cross-training may be needed.
In cross-training, two or more types of exercise are performed in one workout or used alternately in successive workouts. A distance runner in training, for example, may also lift weights twice a week, perform daily stretching exercises, and do high-intensity bicycle sprints every Tuesday.
Exercisers turn to cross-training to fight boredom, but also because no single exercise can yield all the potential benefits of exercise outlined above. Jogging, for example, enhances aerobic fitness (which improves cardiovascular health and requires sustained use of large-muscle groups like those in the legs). But jogging contributes little to developing muscle mass, especially in the upper body. Weight training increases muscle mass, but it does not promote flexibility.
Although cross-training seems to make perfect sense, not all experts agree on its benefits. Cross-training contradicts the time-honored principle that training should be limited in scope and closely aligned to the performance you want to improve. This is known as task specificity, and it means that if you want to be a good distance runner, you need to run mainly long distances. According to this principle, nonspecific activities for runners, like weight training or swimming laps, are a waste of effort because they do not make one a better runner.
Many sports scientists, however, believe that cross-training may lead to optimal effort, because peak performance in any physical activity usually involves more than one physical attribute. A marathoner, for example, may need a strong sprint to the finish line, and hence high levels of aerobic and anaerobic fitness (the ability to perform intense bursts of activity). Also, weight training can help reduce upper-body muscle fatigue while running. Because little overlap exists among attributes like aerobic fitness, anaerobic fitness, and strength, cross-training is required.
The Cross-Training Edge
Cross-training offers advantages for both competitive athletes and those who train simply to keep in shape and manage their weight. Cross-training helps you:
Planning Your Program
A cross-training program usually involves a combination of different exercises, each performed for a specific period. The exercises can all be aerobic, for example, but they usually include other types (table 1).
To improve aerobic fitness, for example, you can bike for 30 minutes. To increase strength, you can lift weights for 30 minutes. You can do one form of exercise each day, or both on the same day. If you do both on the same day, you can change the order in which you do them.
Cross-training also can include diverse exercises in a single routine to promote aerobic fitness, strength, and muscle endurance. For example, in circuit training you do high-repetition, low-resistance weight training and move quickly to the next exercise. Another example is step aerobics using light dumbbells.
You can easily tailor cross-training to your needs and interests. Just select exercises from each of the types in table 1—but you don't have to limit yourself to the activities listed. Then build a program, as in "A Cross-Training Sampler," below. If you are a competitive athlete, talk to an experienced coach when making up your workout schedule.
Remember: This information is not intended as a substitute for medical treatment. Before starting an exercise program, consult a physician.
Dr Stamford is director of the Health Promotion and Wellness Center and professor of exercise physiology in the School of Education at the University of Louisville, Kentucky. He is also an editorial board member of The Physician and Sportsmedicine.