If you are a regular exerciser you may be familiar with the terms “warm up” and “cool down”.
Active cool downs after exercise are often performed with a common belief that it promotes physiological and psychological recovery by reducing muscle soreness, decreasing lactate in the body, reducing post exercise stiffness, and improving your overall ability to back up your training sessions.
Active cool downs involve low-moderate intensity exercise of short duration (~15 min) after the cessation of high intensity training or competition. It differs from a passive cool down, which is simply at the cessation of exercise you sit down and rest.
In many situations people often consider the cool down process as part of their recovery routine.
Active and passive cool downs
A 2018 literature review  suggested that active cool downs provide a short-term improvement in lactate reduction as well as immune system, cardiovascular, and respiratory system recovery. However, a passive cool down displays a similar response to an active cool down within 2 hours of exercise cessation, meaning the practical benefits of these short-term improvements is unclear especially when subsequent exercise is performed >2 hours later.
Unfortunately, the benefit of cool-downs on other aspects of physical ability such as muscle soreness, stiffness and range of motion was negligible, meaning that completing an active cool down is unlikely to assist with long term muscle soreness.
There may be a psychological aspect to cool downs, with many sports people perceiving them as beneficial because it helps with relaxation, socialising, and can be a time to reflect or debrief on the match/exercise performed. In team sports particularly, cool downs often gather the team providing time for discussion of the game and promoting camaraderie.
The psychological benefits may be reason enough for many to continue to include active cool downs in their exercise program, however unless you are performing repeat sessions within a very short time frame, a passive cool down is likely fine if you are short on time.
Active cool down advice
Research has been conducted on many participants with varied results observed. To see if an active cool down works for you, here are some guidelines from the research1 to follow;
- Dynamic whole-body movements (walking, jogging, rowing) that use larger amounts of muscle mass are preferred.
- Activities should be performed at low-moderate intensity to increase blood flow, promote reduction of blood pooling at the extremities and assist in lactate removal. The intensity should be low enough that you are not inducing more fatigue/damage on muscles. The practical tip is that you should be able to hold a conversation easily as you do your cool down.
- Don’t go for longer than 30 minutes.
- Use movements that you or the athlete (if you are coaching) prefer and ideally use similar muscles that were used in the exercise session itself.
 Van Hooren, B., & Peake, J. M. (2018). Do We Need a Cool-Down After Exercise? A Narrative Review of the Psychophysiological Effects and the Effects on Performance, Injuries and the Long-Term Adaptive Response. Sports Medicine (Auckland, N.z.), 48(7), 1575–1595.