Planning Tips For Interval Training

Recovery from exercise depends on a number of factors including your level of fitness, the intensity of the effort and the duration of your workout. A study published in the Journal of Strength and Conditioning Research looks at High Intensity Interval Training (HIIT) above 80% of maximal oxygen consumption and heart rate.
 
On 3 different occasions, 11 recreationally active men in their early 20s did 4x4 minute runs at 90% of maximal aerobic velocity. Each session provided 2 minutes, 3 minutes or 4 minutes of active recovery between bouts. Exercise time above 80% of maximal heart rate was longest during the session that allowed 2 minutes of active recovery, and it also produced the greatest degree of metabolic stress.
 
Since aerobic capacity was enhanced during all HIIT sessions, beginners might want to start with the 4 minute active recovery and gradually work their way up to the more demanding 2 minute variation. Just leave enough time for recovery.