Aerobic versus anaerobic:
is complementary to
. Aerobic literally means
", and refers to the use of oxygen in
' energy-generating process. Aerobic exercise
includes any type of exercise, typically those performed at moderate levels of intensity for extended periods
of time, that maintains an increased heart rate. In such exercise, oxygen is used to "burn" fats and glucose in
order to produce
, the basic energy carrier for all
. Initially during aerobic
is broken down to produce glucose, but in its absence,
metabolism is initiated instead.
The latter is a slow
, and is accompanied by a decline in performance level. The switch to fat as fuel
is a major cause of what
runners call "hitting the wall."
, in contrast, refers to the initial phase of exercise, or any short burst of intense exertion,
in which the glycogen or sugar is consumed without oxygen, and is a far less efficient process.
Operating anaerobically, an untrained 400 meter sprinter may "hit the wall" after only 300 meters.
There are various types of aerobic exercise. In general, aerobic exercise is one performed at a moderately
high level of intensity over a long period of time. For example,
a long distance at a moderate pace is
an aerobic exercise, but
is not. Playing singles tennis, with near-continuous motion, is generally
considered aerobic activity, while golf or doubles tennis, with their more frequent breaks, may not be.
Aerobic: red muscle cell fibers, marathon runner, slow twitch, fatigue resistant, uses Krebs Cycle, products: