Aerobic versus Anaerobic Training

Now that the aerobic training state has been defined by heart rate, let’s update the definitions of both aerobic and anaerobic presented earlier:

 

 

 
  • Aerobic training includes endurance activities performed at or below the maximum aerobic heart rate. The closer an athlete is to this max aerobic rate, the more aerobic stimulation he or she will get from the workout. This includes development of the aerobic system, from increased fat burning and improved circulation to increased aerobic muscle fiber function. Aerobic benefits can still be obtained at lower heart rates. In fact, it’s very important to stimulate aerobic muscle fibers that move the body more slowly, corresponding to lower heart rates.
  • Anaerobic training includes endurance activities performed above the max aerobic heart rate, whether swimming, biking, running, cross-country skiing, or other forms of exercise.

The only exception to this description of aerobic training and heart rate is when a power workout is performed; this includes lifting free weights, using weight machines, performing push-ups, pull-ups, and sit-ups, and similar activities. These are always considered anaerobic, no matter how slow, easy, or light the workload. One reason, as studies show, is that even easy weight workouts can significantly raise the level of the stress hormone cortisol, and can potentially interfere with aerobic function.

A heart-rate monitor won’t provide adequate information regarding the aerobic or anaerobic state during a power workout, such as weight lifting, because of the time factor. In fact, this anaerobic activity often won’t raise the heart rate above the max aerobic heart rate. That’s because you’re not physically active long enough for the heart rate to reach its plateau. For example, as you begin performing a weight workout of, say, fifteen repetitions the heart rate starts to rise. It continues to rise as you reach your limit of fifteen reps and stop. The heart rate will usually remain far below where it would be if you continued lifting the weight—hypothetically, you might not hit the max rate until you got to thirty or forty reps, something you most likely would not be able to accomplish.

In the process of building an aerobic base, it’s usually obvious when aerobic function is improving. You’ll know this is happening because of several things. First, you’ll generally feel healthier. This may be evident because your energy improves, injuries may disappear, and, if your body fat is higher than it should be, you’ll get thinner. However, those with a normal, healthy level of body fat won’t lose any more because that would be unhealthy—building an aerobic base is not just about getting faster, but healthier. Second, you’ll get faster at the same heart rate. For most athletes, this is sufficient proof. But I still prefer to measure, as objectively as possible, this aerobic progress. This can be easily accomplished with the MAF Test, the topic of the next chapter.