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by Dr. Philip Maffetone
A heart rate monitor is still an underrated, misunderstood training companion. Many of today's runners have monitors but don't get their money's worth from them. Heart rate monitors are really just biofeedback units. But without interpretion of the data they provide, their true benefits cannot be realized. Dorland's Medical Dictionary defines biofeedback as "the process of providing visual or auditory evidence to a person of the status of body function so that you may exert control over that function." As students in the 1970s involved in a biofeedback research project, we measured responses in human subjects to various physiological inputs; sounds, visual effects, and a variety of physical stimulation, including activity. The observed reactions were evaluated by measuring temperature, sweating, and heart rate.
It became evident that using the heart rate to objectively measure body function was simple, accurate, and useful. And its application in sports was obvious. For me, this was the beginning of a long process of using heart monitors with athletes. By the early 1980s, I was using monitors for three important running applications: - Training
- Self-assessment
- Racing
TrainingThe use of a heart rate monitor for effective training entails two important aspects. The first is that all endurance athletes must build a good aerobic base, a notion that famed running coach Arthur Lydiard promoted decades ago. The second consideration has to do with the specific heart rate used during training, and how a runner determines that important number. Let's look at each feature separately.
Building a good aerobic base means training only aerobically. During the base period, no anaerobic workouts (including racing) should be incorporated. Anaerobic activity will jeopardize the efficient development of your aerobic base, so every workout is aerobic. That includes your long run on Sunday, your hilly runs in the park, and any other workouts where you're heavily influenced by other athletes or the terrain. In addition, an aerobic base period is devoid of weight training, since lifting is also an anaerobic workout. There may be several reasons why anaerobic workouts can inhibit aerobic base building: - Anaerobic training can decrease the number of aerobic muscle fibers, sometimes significantly. This can happen in just a few short weeks of higher heart rate training.
- The lactic acid produced during anaerobic training may inhibit the aerobic muscle enzymes necessary for building an aerobic base.
- Anaerobic training raises your respiratory quotient. This means the percentage of energy derived from sugar increases and fat burning decreases. In time, this may force more anaerobic metabolism and less aerobic function.
- Stress can also inhibit the aerobic system. Stress is nearly synonymous with anaerobic training. Excess stress raises cortisol levels, which ultimately increases insulin levels, inhibiting fat burning and increasing sugar usage. This promotes anaerobic metabolism and inhibits aerobic activity.
Aerobic base training is often the period of training where discipline, dedication, and hard work are most important. Most athletes think these three mental attributes are related to toughing it out, grunting, and training in pain. But it's sometimes harder than that: training properly during the aerobic phase, for many athletes, is the most difficult part of my program. It's the ability to go slower, despite what other athletes are doing and saying.
For the longer running events, 95-98% of racing energy is obtained from the aerobic system. This is another reason I recommend that most training be directed at improving this process. Building a good aerobic base takes about three months. For runners who have lost their competitive edge, have chronic problems (injury, sickness), or cannot lose that extra fat, a longer base - up to six months - can work wonders. But the question remains: what heart rate do you use for aerobic training? Perhaps the most important feature of training with a heart monitor is knowing which heart rate to use. We're familiar with the old formula: 220 minus your age, multipied by 65-85%. But this method has no basis. Your maximum heart rate is supposed to be represented by 220 minus your age. However, if you've ever pushed yourself on the track or in a race to find your highest heart rate, you may have found, as more than half of the population does, that it is not the same as the formula. Then there's the percentage: which do you use - 65%, 75%, 80%? Rather than guess, you can use a newer formula which is scientifically based. See the insert on the 180 Formula, which establishes the best heart rate for building an aerobic base. Initially, training at this heart rate induces emotional stress in many athletes. "I just can't train that slow!" is a common comment. But after a short time, not only will you feel better, but your pace will quicken at that same training heart rate. One significant benefit of applying the 180 Formula to your training is the chemical response by the body: production of free radicals is minimal compared to running at heart rates even a little higher. These chemicals can contribute to degenerative problems, inflammation, heart disease, and cancer, not to mention speeding the aging process. By using the 180 Formula, you can run more miles without risking chemical stress. |
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发表于 2009-2-1 11:21:01
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