Aerobic exercise means you are utilizing oxygen pathways to produce energy. It is continuous and the duration is 20-60 minutes in length. Large muscle groups are utilized.
Anaerobic exercise means you are utilizing pathways without oxygen to produce energy. It is of short duration (less than 20 minutes) and is intermittent. Lactic Acid is produced as a bi-product of the energy metabolism without oxygen.
For cardiovascular exercise, start with 15 minutes in the target heart range three times per week. Add 5 minutes per week up to 60 minutes, then add one day per week up to five days per week maximum, depending on your goals.
There are three energy pathways:
1. ATP-PC (Anaerobic uses carbohydrates) 2. Lactic Acid (Anaerobic uses carbohydrates) 3. Oxidative (Aerobic uses fat)
Interval training (alternating periods of all out exertion with rest periods) may be used to work on one of the three specific energy pathways for sports, to burn more calories in a given amount of time, or increase your cardiovascular conditioning. You will want to vary the work to rest ratio to target the different pathways. You should use a 1:15 work to rest ratio to target the ATP-PC system, more of a 1:8 work to rest ratio to target the Lactic Acid system, and a 1:1 work to rest ratio to target the Oxidative System.