High-Intensity Exercise
Steady-state exercise involves long, continuous exercise sessions where you maintain the same intensity level throughout your workout, such as jogging for an hour. High-intensity exercise sessions alternate intense bouts of exercise with less intense bouts, called recovery periods. The recovery periods are necessary because you cannot maintain intense exercise for long periods. Exercise intensity and duration are inversely proportional to one another. If the duration is long, the intensity is low; if the intensity is high, the exercise duration is low.
Recovery Periods
Recovery periods can be active or passive. You don't do any activity during a passive recovery period. You simply sit, stand or do light stretching. During an active recovery period, you do a less intense activity. It can be a less intense version of the high-intensity bouts or it can be a different type of activity. For example, if you are sprinting, you can jog for the active recovery. But you can also do something different, such as riding an exercise bike.
Benefits
When active recovery periods are used during high-intensity exercise, the peak power between exercise bouts decreases less than when passive recovery periods are used, according to a study published in the "Canadian Journal of Applied Physiology." Athletes were able to maintain higher power levels, measured in watts, when they kept active during the recovery periods. The American Council on Exercise states that during an active recovery period, your muscles remove metabolic waste and prime your energy stores for the next high-intensity bout.
Bottom Line
If your goal is to improve your general level of fitness or to drop a couple of pounds, the type of recovery period you use might not matter as much as it does for an athlete who tracks every ounce of performance improvement. If you are a beginner exerciser, you may need to start with passive recovery and work your way up to active recovery periods.
No standards or definitions exist for the exact intensity level of an active recovery period. If you use a 10-point scale to rate your intensity level, the American Council of Exercise recommends a 7 or 8 for the high-intensity bouts and a 4 or 5 for the active recovery bouts.
