Exercise and mood: what acute and regular physical activity change, and why exertion is not venting

Two questions that are easy to merge

“Exercise helps with emotions” is one of the most repeated pieces of wellness advice, and one of the best supported. It also conceals two different questions and one tempting mistake.

The first question concerns acute effects: what happens to affect during a session of physical activity and in the hours afterwards. The second concerns regular activity: whether people who exercise over weeks or months show lower levels of depression, anxiety or distress than comparable people who do not. The evidence for these questions comes from different designs and supports different kinds of statements.

The tempting mistake is to read the acute lift in mood as a discharge, as if exertion burned off a quantity of anger or tension. That reading is the hydraulic model of emotion in athletic dress, and the evidence on anger does not support it (Research note 02). This note takes the questions in turn and then returns to the mistake.

Acute effects: a lift in positive, energetic affect

Reed and Ones (2006) meta-analysed studies of single sessions of aerobic exercise and positive activated affect, the family of feelings described as energetic, alert or enthusiastic. The abstract of that meta-analysis could not be retrieved for this library, so its study counts and effect sizes are not reported here; the library records it as support for a short-term increase in positive activated affect, held at moderate confidence (Research note 04).

Laboratory sessions are one thing; everyday life is another. Liao, Shonkoff and Dunton (2015) reviewed studies of the acute relations between affect and physical activity in free-living, naturalistic settings in non-clinical populations, typically using repeated momentary reports during the day. They identified 14 eligible studies. Twelve tested affective states after physical activity and yielded consistent evidence that activity predicted higher positive affect over the next few hours, with some evidence of more energetic feelings. The evidence that physical activity reduced negative affect in the next few hours was inconsistent and inconclusive. Six studies examined the reverse direction and found that positive affective states were associated with more physical activity over the next few hours, while negative states had no significant association.

Three points follow from this pattern.

The best-supported acute change is an increase in positive, energetic feeling, not a decrease in distress. This matters for anyone who exercises specifically to get rid of a bad feeling. The evidence from daily life is stronger for “feeling more energetic afterwards” than for “feeling less upset afterwards”.

Direction runs both ways. People who already feel good are more likely to be active, so everyday associations between activity and mood are partly the result of mood shaping activity. The designs reviewed are observational and cannot rule out that both are influenced by something else, such as a free afternoon or good company.

The effect is time-limited. “Over the next few hours” is the scale at which these studies measured. An acute lift is real and useful, and it is a change in state, not in the circumstances that produced a difficult emotion.

Intensity: why “harder” is not “better” for how exercise feels

If exertion discharged tension, harder exertion should feel better. The research on intensity points the other way. Ekkekakis, Parfitt and Petruzzello (2011) reviewed 33 articles published between 1999 and 2009 on the relation between exercise intensity and affective responses. Pleasure was reduced mainly above the ventilatory or lactate threshold, the point beyond which the body can no longer meet the demand aerobically. Below that threshold, most people experienced pleasant changes; close to it, individual variability was large; above it, changes were homogeneously negative. When people selected the intensity themselves, rather than having it imposed, they appeared to tolerate higher intensity levels.

The authors’ main concern is exercise adherence: people are more likely to repeat what felt pleasant. For emotion regulation the review has a direct implication. The pleasant affect that people seek from exercise is most reliably found at moderate, self-chosen intensities. Pushing to exhaustion in order to “get it out” moves exertion into the range where the experience during exercise tends to become unpleasant.

Regular activity: depression, anxiety and distress

The second question has been studied with randomised trials, and it has been synthesised many times. Four syntheses illustrate what is known and how certain it is.

Rebar and colleagues (2015) conducted a meta-meta-analysis of the effects of physical activity on depression and anxiety in non-clinical adult populations. They identified eight meta-analytic outcomes of randomised trials, based on 92 studies with 4,310 participants for depression and 306 study effects with 10,755 participants for anxiety. Physical activity reduced depression by a medium effect (standardised mean difference, SMD = -0.50, 95% CI -0.93 to -0.06) and anxiety by a small effect (SMD = -0.38, 95% CI -0.66 to -0.11). Neither effect showed significant heterogeneity across meta-analyses. Because meta-analyses can include overlapping trials, a meta-meta-analysis counts some evidence more than once, and the wide confidence interval for depression is a reminder that the size of the effect is uncertain.

Schuch and colleagues (2016) focused on people with depression, including major depressive disorder. They included 25 randomised trials comparing exercise with control conditions, 9 of them in major depressive disorder. After adjusting for publication bias, exercise had a large effect on depressive symptoms (SMD = 1.11, 95% CI 0.79 to 1.43). Larger effects were found for aerobic exercise at moderate and vigorous intensities. Most of their adjusted analyses suggested that publication bias had led earlier meta-analyses to underestimate the effect, which is the unusual direction.

Noetel and colleagues (2024) conducted a systematic review and network meta-analysis of 218 randomised trials with 14,170 participants who met clinical cut-offs for major depression. Compared with active controls such as usual care or a placebo tablet, moderate reductions in depression were found for walking or jogging (Hedges’ g = -0.62), yoga (g = -0.55), strength training (g = -0.49), mixed aerobic exercise (g = -0.43) and tai chi or qigong (g = -0.42). The effects were proportional to the intensity prescribed. The results appeared robust to publication bias, but only one study met the Cochrane criteria for low risk of bias, and confidence in the estimates was rated low for walking or jogging and very low for the other treatments. The authors note that expectancy effects could be reduced by blinding participants and staff, which is difficult in exercise trials.

Singh and colleagues (2023) took the widest view, an umbrella review of 97 systematic reviews covering 1,039 trials and 128,119 adult participants, including healthy adults, people with mental health disorders and people with chronic diseases. Physical activity had medium effects on depression (median effect size -0.43), anxiety (median -0.42) and psychological distress (-0.60) compared with usual care. Higher intensity was associated with greater improvements, and effectiveness diminished with longer interventions. Most of the included reviews (77 of 97) had a critically low quality score on the instrument used to assess them.

Taken together, these syntheses consistently associate regular physical activity with lower depressive and anxiety symptoms in randomised comparisons. The size of the effect depends on population, comparison and analysis, and the certainty is limited by trial quality and by the impossibility of blinding people to whether they exercise. The appropriate wording is that exercise is supported as a way of reducing symptoms, with moderate confidence in the direction and less in any particular number.

Intensity again: a tension to hold

Two findings above appear to pull in different directions. For how exercise feels during a session, pleasure declines above the ventilatory threshold. For regular exercise and symptoms, higher intensity was associated with larger improvements. These are different outcomes on different time scales, and they are compatible: an unpleasant session can still contribute to a later reduction in symptoms. What they do not support is the idea that intensity is valuable because it discharges emotion. The clinical trials measured symptoms over weeks, not release within a session.

The same tension has a practical side. Unpleasant exercise is less likely to be repeated, and the benefits in trials came from repetition. Self-selected intensity, which Ekkekakis and colleagues found to foster tolerance of higher intensity, is one way to reconcile the two.

Why exertion is not venting

Kjærvik and Bushman (2024) meta-analysed 154 studies of anger management activities and classified them by their effect on physiological arousal. Arousal-decreasing activities, such as deep breathing, mindfulness and meditation, reduced anger and aggression (g = -0.63). Arousal-increasing activities, including hitting a bag, jogging and cycling, were ineffective overall (g = -0.02), with heterogeneous results. The authors concluded that the findings do not support venting anger or going for a run as effective anger management activities. The meta-analysis and its limits are described in Research note 02.

This can look like a contradiction of everything above. It is not, once outcomes are separated. The exercise literature measures positive affect, depressive and anxiety symptoms, and distress. The anger literature measures anger and aggression, usually shortly after a provocation. An activity can lift energetic positive affect and still leave anger, measured at the same time, where it was.

Two further findings sharpen the distinction. First, exertion raises arousal, and arousal is not tied to a particular emotion. In Bushman’s (2002) experiment, participants who hit a punching bag while thinking about the person who provoked them reported more anger than both other groups and behaved most aggressively; in aggression, those who hit the bag while thinking about getting fit fell between that group and a group that sat quietly. What people attend to while their arousal is high appears to shape what that arousal becomes. Second, the acute effect that daily-life studies support is an increase in positive affect, not a reliable decrease in negative affect. Exercise is therefore better understood as adding something (energy, a sense of capability, often company and a change of setting) than as removing a stored quantity of anger.

The practical reading is straightforward. When angry, lowering arousal first is the approach with meta-analytic support. Physical activity is valuable for mood, and it is most compatible with anger reduction when it does not become a rehearsal of the grievance, and when its intensity is not used as a way of “getting it out”.

Relevance to catharsis

Exercise is a clear case of a restorative experience that feels like release. People say they “ran it off” or “sweated it out”. The evidence supports part of that experience: a real, short-lived lift in positive, energetic affect and, with regular practice, lower symptoms of depression and anxiety. It does not support the discharge metaphor. The benefits appear with moderate, repeated activity, not with a single exhausting burst, and exertion without a change in attention did not reduce anger.

That is the distinction this library draws between relief and resolution (Research note 04). Exercise can make a state easier to bear, and over time it can change symptom levels. It does not by itself change what produced the state in the first place.

Practical implications, with limits

• Use physical activity for mood on its own terms. A walk, a ride or a session at a comfortable, self-chosen intensity is a reasonable way to lift energy for the next few hours.
• Do not use exertion to discharge anger. Lower arousal first; if you move, keep attention on the activity rather than on the grievance.
• Think in weeks, not sessions. The trial evidence on symptoms concerns regular activity; one hard session is not the unit of benefit.
• Exercise is not a substitute for care. Trials in depression are encouraging, and exercise is often recommended alongside other treatments, but persistent low mood, anxiety or hopelessness warrants assessment by a qualified professional.

These implications follow from the evidence but have not been tested as a package. People with medical conditions should consider advice on appropriate activity from a clinician.

Limits of the evidence

Acute evidence from daily life is observational and runs in both directions. The acute meta-analysis on positive activated affect could not be re-verified from an abstract. The trial evidence on regular activity comes from syntheses with overlapping studies, frequent risk of bias, unblinded participants and, in the umbrella review, mostly low-quality reviews. The anger meta-analysis found heterogeneity among arousal-increasing activities, so specific activities in specific contexts may differ from the average. The evidence ledger records the grade and review date of each claim.