[This article originally appeared in the
April 2001
issue of Northwest Runner
magazine.]
In its first year of existence, this column has focused on the physical aspects of endurance training -- which workouts to do, which foods to eat, etc. -- and has not delved deeply into the mental side of things. In part, this is because I find most sports psychology research to be confusing, of poor quality, or focused on "skill" sports rather than endurance exercise. Nevertheless, as fellow scribe Kim Bender will attest, what goes on in one's head can have a profound impact on athletic performance, even in sports as repetitive and "easy" as running. This month, we'll discuss a technique known as biofeedback -- one of the few topics in sports psychology that has been addressed with good research relevant to distance runners.
William Morgan and his colleagues were among the first researchers to study the interaction of the mind and the exercising body. For example, in one rather amusing experiment, Morgan et al. (American Journal of Clinical Hypnosis 18: 182-90, 1976) got a bunch of college students to pedal a stationary bicycle while under hypnosis. These subjects maintained a constant workload of 100 Watts for 20 minutes of cycling; however, from the 10th to the 15th minute of exercise, they were told that they were pedalling up a steep hill. As the students climbed this nonexistent "hill," their breathing (i.e., total intake of air into the lungs per minute) rose by about 20%. Breathing then dropped when they were told that they were once again riding on level terrain.
Just calm down, OK?
The above-mentioned study shows that one's thoughts can indeed alter the body's response to exercise, but how many athletes scale imaginary hills while hypnotized as a regular part of their training? And is it possible to decrease such variables as one's breathing rate during exercise? In other words, rather than making exercise more stressful to the body than it should be, can certain mental adjustments make it less stressful? With these questions in mind, a number of scientists have attempted to determine whether people can "calm their bodies down" during normal exercise.
What has been found, in short, is that people can to some extent reduce their breathing and cardiac output (i.e., work done by the heart) during exercise if they employ a strategy known as biofeedback. Biofeedback is defined as any process in which a person's physiological variables are reported back to him/her as they are being measured (Zaichkowsky & Fuchs, Exercise and Sport Sciences Reviews 16: 381-421, 1988). A heart rate monitor is thus a good example of a simple biofeedback device.
An interesting offshoot of this research concerns its application to patients with cardiovascular problems such as hypertension or angina. Cardiovascular disease makes the heart less able to respond to the demands of exercise; however, biofeedback may allow patients to reduce the stress put on the heart during exercise (Johnston & Lo, Behavioural Psychotherapy 11: 257-64, 1983; Fredrikson & Engel, European Journal of Applied Physiology 54: 315-20, 1985).
What about HARD exercise?
A limitation of the above studies is that they all involved low-intensity exercise, in which heart rates averaged 95 to 120 beats per minute. Is biofeedback also useful during more vigorous race-pace efforts? To find out, Hatfield et al. (Medicine and Science in Sports and Exercise 24: 218-25, 1992) had twelve collegiate cross-country runners run on a treadmill at speeds fast enough to elicit average heart rates of 160 to 170. When the runners were given given biofeedback on their breathing, they were able to breathe less (i.e., inhale less air per minute) than when they ran without biofeedback.
The Hatfield study provided a preliminary indication that biofeedback may be useful during race-like situations, at least as a way of preventing excessive huffing and puffing. However, a more direct demonstration of its benefits was provided by Caird et al. (Medicine and Science in Sports and Exercise 31: 717-22, 1999), who combined biofeedback with a relaxation technique known as "centering," which (according to the authors) emphasizes abdominal breathing and the use of key words. The runners studied by Caird et al. received biofeedback information on their breathing, heart rate, and oxygen consumption, and they used centering to try to keep these things as low as possible. After several weeks of practice, these runners were able to reduce the amount of oxygen they used while running at an assigned pace; in other words, their running economy improved. Running economy -- the effectiveness with which the body converts oxygen consumption into forward motion -- is an important determinant of endurance performance, as was discussed in the February '01 and March '01 installments of this column. Thus, while further research is needed, these results suggest that biofeedback and relaxation can in fact help athletes perform better in long-distance races.
DO try this at home
Although most of us do not have access to a laboratory full of treadmills and medical instruments, a simplified version of the above protocol can be carried out by anyone with a heart rate monitor. To follow the lead of Caird et al., you might begin by learning to "center" yourself while standing still. According to Robert Nideffer's book Athletes' Guide To Mental Training, this can be done roughly as follows. (1) Breathe deeply from the abdomen, not from the chest. (2) Focus your attention on your center of gravity, which is located just behind your belly button. (3) Check the tension in your muscles when you inhale; let the tension flow out of your muscles when you exhale. When you've gotten the hang of this, try it while running. (Synchronizing your breathing with your strides may help.) Then test yourself: see if you can lower your heart rate while maintaining a constant speed. Don't be surprised if your initial attempts are unsuccessful; Caird et al.'s subjects did not benefit fully from their biofeedback ritual until they had been doing it for six to twelve weeks. With a lot of practice and a little luck, though, you'll be on your way to becoming a more efficient runner.