tively inform you of an obstacle long before you feel bad or get
injured. If something interferes with your progress, such as exercise
itself, diet or stress, you don’t want to wait until you’re feeling bad or
gaining weight to find that out. In these situations where your aero-
bic system is no longer getting benefits, your MAF Test will show it
by getting worse, or not improving.
Phases of Aerobic Function
An important element of the MAF Test is knowing what is normal
and what isn’t. During your exercise program, you could encounter
three different phases: progression, plateau and regression.
When you successfully develop your aerobic system, you will
have more energy and better aerobic function, with corresponding
improvements in your MAF Test. This is the progressive phase, and it
can and should continue for many years without regression. As you
improve, further progression will happen more slowly. For example,
the first year your walking may improve from 18 minutes to 13 min-
utes per mile. The second year, your improvement may only go from
13 minutes per mile, walking, to 10 minutes per mile, jogging.
There will also be periods of plateaus. Actually, there are two dif-
ferent kinds of plateaus, one normal and the other unhealthy. With
improvement, you will eventually arrive at a normal leveling off —
almost as if your body needs a rest from the progress it’s making. The
metabolic, neurological and muscular aspects of the body require a
period of adjustment, and the body may need some time for a recov-
ery. These normal plateaus shouldn’t last too long, perhaps a few
weeks to a few months. Then, progress should resume, as measured
by the MAF Test. If you stay in your plateau for longer periods, it may
be abnormal.
An abnormal plateau is due to some obstacle that prevents
progress. The MAF Test can help diagnose an abnormal plateau. Once
your test has stayed the same for too long, the next step is to find out
why. There could be many factors.
The most common reason for an abnormal plateau is stress.
Remember, stress can be physical, chemical or mental. Typically, some
lifestyle stress or stresses could cause your aerobic system to plateau.
The weather may also be a stress that can halt progression.
HEART-RATE MONITORING • 205