Cool-down and stretching after a workout

The cool-down and stretching at the end of a workout are often seen as a mandatory ritual that «flushes out lactic acid» and saves you from soreness. Scientific data paint a more restrained picture: some of these expectations are not borne out, and part of the benefit lies in an entirely different area. Our editorial team examined what the final part of a session actually provides and how to make it useful rather than merely a formality.

What a cool-down is and why it is needed

A cool-down is a period of low-intensity activity immediately after the main part of a workout: slow walking, easy pedaling on a stationary bike, calm rowing or a slow jog. It usually lasts from five to fifteen minutes. Static stretching, breathing exercises or foam-roller work are often added to the cool-down, although from a physiological standpoint these are different tools with different effects.

The main function of a cool-down is a gradual rather than an abrupt transition of the body from a state of high load to a state of rest. During intense work the heart pumps a large volume of blood, the vessels of the working muscles are dilated, and the return of venous blood to the heart is largely ensured by the «muscle pump» — the rhythmic contraction of the leg muscles. If you suddenly stop, the pump switches off, blood partly pools in the lower limbs, and blood pressure can drop.

This is precisely why, after prolonged running or intense intervals, some people experience dizziness or even fainting if they immediately sit down or stand still. This phenomenon is described as post-exercise hypotension. Light movement for a few minutes allows the cardiovascular system to adapt gradually and reduces this risk.

Another argument in favor of a cool-down is psychological. A few minutes of calm work help reduce arousal, restore the breathing rhythm and «close out» the workout consciously. For many people this is the moment to assess how they feel, record their results and notice discomfort that was masked by adrenaline during the main part.

Myths about lactic acid and soreness

The most popular explanation of the cool-down’s benefit goes like this: it «flushes lactic acid out of the muscles» and therefore prevents next-day pain. Both parts of this claim need clarification. First, lactate is not «waste»: it is a fuel actively used by the heart, undamaged muscle fibers and the liver. Second, its blood level returns to baseline within about an hour even at complete rest.

An active cool-down does indeed speed up the decline in blood lactate concentration compared with passive rest — this has been shown in many studies. However, for an ordinary person whose next workout is a day or two away, this difference is practically meaningless. It may matter only for athletes who compete several times a day, for example in swimming or wrestling.

Soreness, or delayed-onset muscle pain, is not related to lactate at all. It arises from micro-damage to muscle fibers and connective tissue and the subsequent inflammatory reaction, most often after unaccustomed load or eccentric movements — lowering a weight, running downhill. The pain peaks 24–72 hours after the workout, when there has long been no lactate in the muscles.

A review by Van Hooren and Peake (2018), which analyzed studies of active cool-downs, concluded that it does not significantly reduce soreness, does not speed up the recovery of strength and has no convincing evidence for injury prevention. At the same time, the authors do not consider the cool-down harmful — its effects are simply more modest than is commonly thought.

• Myth:a cool-down «flushes out lactic acid» and is therefore mandatory.Fact:lactate is cleared even without it, and this has no effect on the next workout.
• Myth:without a cool-down there will be severe soreness.Fact:pain is determined by the novelty and the eccentric component of the load.
• Myth:a cool-down prevents injuries.Fact:there is as yet no quality evidence for this.

Stretching after a workout: what is proven

Static stretching is traditionally recommended at the end of a session, when the muscles are warm. A Cochrane review by Herbert and colleagues (2011) assessed whether stretching before or after exercise reduces delayed-onset muscle pain. The conclusion was unambiguous: the effect is so small that for most people it has no practical significance. In other words, you should not count on stretching as a remedy against soreness.

A later meta-analysis by Afonso and colleagues (2021) also found no evidence that stretching after a workout speeds up strength recovery or reduces pain in the days that follow. However, this does not make stretching useless. Its main proven benefit is a gradual increase in the range of motion in the joints when performed regularly over weeks and months.

The final part of a workout is simply a convenient time for this work. The body is warm, the next strength exercise does not interfere with working on flexibility, and the process itself helps you calm down. A systematic review by Behm and colleagues (2016) showed that the drop in strength after static stretching appears mainly with long holds of over 60 seconds and matters before a performance, not after it.

So stretching after a workout should be regarded as a separate component of the program — work on flexibility, not a recovery procedure. If you have no problems with range of motion and your sport does not require it, skipping stretching will not harm your results. But if, for example, limited hip mobility prevents you from squatting deeply, regular stretching will help.

How to structure a cool-down: a practical scheme

Since the high expectations of a cool-down are not fulfilled, there is no point in spending half an hour on it. A short but meaningful block that solves real tasks is enough: smoothly lower the pulse, restore breathing, work on the mobility of exactly those areas that need it. Below is a scheme that our editorial team considers a reasonable standard for most amateurs.

The intensity of the cardio part of the cool-down should be such that you can talk freely. A good guideline is a gradual reduction of pace until your breathing becomes calm and your pulse drops below roughly a hundred beats per minute. For older people or those with cardiovascular disease this stage is especially important and is best not shortened.

For stretching, choose areas that limit your technique or are tight because of your lifestyle: the hamstrings, hip flexors, chest muscles, calf muscles. ACSM guidelines recommend holding a static stretch for 10–30 seconds, and for older people 30–60 seconds, performing several repetitions. The stretch should be noticeable but not painful.

A foam roller can be used as a supplement: some studies show a short-term subjective reduction in the feeling of stiffness. However, it is not a mandatory tool, and its effects should not be overestimated. If time is short, it is better to devote it to the main part of the workout than to skip a set for the sake of the roller.

Who needs a cool-down the most

For most people who do strength training at a calm pace with rest between sets, the pulse drops by the end of the session anyway, so a separate cardio cool-down is more of a pleasant addition. After intense running, cycling, interval or circuit training, however, an abrupt stop can be unpleasant, and a few minutes of light movement are clearly appropriate.

People with arterial hypertension who take blood-pressure-lowering medications, such as alpha-blockers or vasodilators, deserve special attention. Their risk of a sharp drop in pressure after exercise is higher. A cool-down should also not be skipped in the heat, when the skin’s vessels are dilated and part of the plasma volume has been lost through sweat.

For athletes who have two starts or two sessions in a day, an active cool-down may help restore some metabolic indicators more quickly between performances. In their case the goal is different from an amateur’s, and the recovery plan is usually drawn up by a coach taking the competition schedule into account.

For people with joint hypermobility, on the contrary, aggressive stretching may bring no benefit: they more often need stabilization and strength work rather than increased range of motion. If you notice that your joints are «loose» or frequently give way, it is better to discuss your program with a physical therapist.

Editorial conclusions

A cool-down is useful primarily as a smooth transition from load to rest: it reduces the risk of dizziness after intense work and helps you calm down. Claims about «flushing out lactic acid» and protection from soreness are not scientifically confirmed.

Stretching after a workout does not speed up recovery and has almost no effect on pain, but when performed regularly it increases range of motion. So it should be seen as a separate block of flexibility work, not as a «cure» for exertion.

An optimal cool-down for an amateur takes 5–15 minutes: a few minutes of light cardio, a couple of minutes of breathing and targeted stretching of the areas that limit your technique. This is quite enough to gain real benefit without wasting time.

Our editorial team also recommends reading our materials on the warm-up before strength training, on delayed-onset muscle pain and recovery methods, and on the role of sleep in progress.

References

1. Van Hooren B, Peake JM. 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 Med. 2018;48(7):1575–1595.
2. Herbert RD, de Noronha M, Kamper SJ. Stretching to prevent or reduce muscle soreness after exercise. Cochrane Database Syst Rev. 2011;(7):CD004577.
3. Behm DG, Blazevich AJ, Kay AD, McHugh M. Acute effects of muscle stretching on physical performance, range of motion, and injury incidence in healthy active individuals: a systematic review. Appl Physiol Nutr Metab. 2016;41(1):1–11.
4. Afonso J, Clemente FM, Nakamura FY, et al. The effectiveness of post-exercise stretching in short-term and delayed recovery of strength, range of motion and delayed onset muscle soreness: a systematic review and meta-analysis of randomized controlled trials. Front Physiol. 2021;12:677581.
5. Garber CE, Blissmer B, Deschenes MR, et al. American College of Sports Medicine position stand. Quantity and quality of exercise for developing and maintaining cardiorespiratory, musculoskeletal, and neuromotor fitness in apparently healthy adults. Med Sci Sports Exerc. 2011;43(7):1334–1359.
6. American College of Sports Medicine. ACSM's Guidelines for Exercise Testing and Prescription. 11th ed. Wolters Kluwer; 2021.