Anaerobic Interval Training
The anaerobic (interval) phase of this exercise program is in place for the following reasons:
1. Anaerobic intervals lead to a large caloric expenditure during the exercise but also a large EPOC (post exercise metabolic rate).
2. Anaerobic intervals lead to increased aerobic, anaerobic, and ATP-PC enzyme activity. These enzymes are responsible for regulating the energy pathways of the muscle. By up-regulating these enzymes, you'll burn more fat and carbohydrates.
3. Anaerobic intervals can lead to increased muscle size in the working muscles.
4. Anaerobic intervals lead to an increased SR (sarcoplasmic reticulum). The SR is responsible for the calcium balance and contractile regulation of the muscle.
5. Anaerobic intervals can lead to an increased % of FT (fast twitch) fibers (IIA) and a loss of the ST (slow twitch) fibers (I). The fast twitch fibers are better suited to strength and power as well as growth.
Aerobic Training
And finally, the aerobic phase of this program is in place for the following reasons:
1. Aerobic exercise is the most energy costly exercise.
2. Aerobic exercise can increase maximal oxygen consumption during any given work intensity (and therefore fat metabolism during any sub maximal work intensity)
3. Aerobic exercise can increase the aerobic/oxidative enzymes by 40-50%. This leads to better fat burning at rest and during exercise.
4. Aerobic exercise can lead to an increase in capillary density by 50%. This means more blood flow to the working muscles.
5. Aerobic exercise can lead to an increased reliance on fat metabolism while sparing glycogen.