Cardio Training – Can It Impact Emotions?

Over the past decades, an increasing number of studies have underscored the benefits of regular physical activity—particularly aerobic exercise—not only in the context of physical health but also concerning mental and emotional well-being. The role of exercise in enhancing mood, reducing stress, and modulating emotions is receiving ever-growing recognition, especially in light of the escalating health challenges associated with modern, sedentary lifestyles. Aerobic physical exertion demonstrates a capacity to influence cognitive and emotional processes, thereby significantly affecting an individual’s quality of life.

Aerobic exercises, such as running, swimming, cycling, or brisk walking, are frequently employed as adjuncts in combating psychological issues, including depression, anxiety, and mood disorders. Research indicates that regular physical activity can play a crucial role in emotion regulation, aiding individuals in better managing daily stress and improving overall well-being. However, despite widespread acceptance of these phenomena, the underlying mechanisms through which aerobic exercise influences emotions remain not yet fully elucidated.

Factors influencing mood during workouts

Intensity

The relationship between exercise intensity and its impact on emotional regulation is characterized by an inverted U-shaped curve, whereby moderate intensity is optimal for emotion regulation. At a physiological level, moderate-intensity aerobic exercise can augment the release of catecholamines, such as dopamine, while concurrently attenuating serotonergic neuronal activity (5-HT), thereby facilitating emotional processing and stress resilience. This level of exercise intensity also elevates plasma endorphin levels, evoking pleasurable sensations and positive emotional experiences. Additionally, there is an increase in endocannabinoid levels, which help mitigate anxiety and other negative emotional states. At this intensity, the partial pressure of carbon dioxide and cerebral blood flow remain near resting levels. When heart rate (HR) is maintained at approximately 60–70% of maximal heart rate (HRmax), early sensitivity to negative stimuli is reduced, emotional regulation is enhanced, emotional recovery time is shortened, impulse control is improved, and negative emotions — such as sadness — are effectively alleviated.

Lower-intensity activities, such as walking that elicits a heart rate below 60% HRmax, do not significantly impact the regulation of emotions like sadness, anger, or anxiety in the short term. In contrast, running for the same duration exhibits improvements in these negative emotional states. Individuals engaging in very low-intensity exercise (~40% HRmax) display an augmented amygdala response to fear compared to joy. Conversely, high-intensity exercises (~75% HRmax), such as vigorous running, elicit an opposite effect—likely due to the intensity-dependent release of both endorphins and catecholamines, with effects intensifying at higher exercise intensities. Low-intensity exercises may not induce sufficient physiological changes to effect significant emotional-cognitive alterations. Furthermore, with high-intensity exercises that exceed the maximal oxygen uptake, there is a tendency toward hyperventilation, which decreases the partial pressure of carbon dioxide in the blood and consequently reduces oxygen levels in the cerebral cortex—particularly in the prefrontal cortex. Such high-intensity activities, often perceived as threatening, may provoke adverse emotional states. Intensities that elevate heart rate to around 87% HRmax can increase perceived stress. However, in a minority of cases—especially among athletes or individuals with higher fitness levels who routinely engage in aerobic training—significant improvements in cognitive reappraisal have been observed following high-intensity interventions (~96% HRmax/average heart rate 187 bpm).

Volume

Integrating contemporary experimental paradigms and findings, the relationship between emotion regulation performance following a single bout of aerobic exercise and exercise duration also follows an inverted U-shaped curve. It has been observed that a single session of aerobic exercise lasting between 20 and 30 minutes can transiently improve emotion regulation capabilities. For instance, cycling on an ergometer for 20–25 minutes increased the efficiency of emotion regulation when subjects were subsequently exposed to emotionally negative images, concurrently alleviating negative emotional responses. A 30-minute aerobic training session helped attenuate neurophysiological responses to negative stimuli and improved the capacity for cognitive reappraisal. Conversely, aerobic exercises lasting less than 10 minutes did not enhance emotion regulation when subjects viewed negatively charged films or images, whereas sessions extending beyond 75 minutes exerted a deleterious impact on emotional states.

During exercise, the synthesis and release of neurotransmitters and neurotrophic factors, as well as the transport of nutrients from peripheral blood through the blood-brain barrier, require time. As the availability of glucose and dopamine in the brain increases during an exercise session, overall neural activity is enhanced. On one hand, sessions that are too brief yield minimal effects, insufficient to reach statistical significance. On the other hand, excessively prolonged exercise sessions may lead to a reduction in cerebral blood flow by up to 20%, thereby diminishing the efficiency of neural processing. This reduction is counterproductive to emotion regulation strategies, such as cognitive reappraisal or expressive suppression, which demand substantial cognitive resources. 

Training Experience

Prior exercise experience is a critical factor influencing the efficacy of aerobic interventions in emotional regulation; it modifies the thresholds for both exercise intensity and session duration, as depicted by the inverted U-shaped curves. Individuals with extensive running experience (weekly mileage exceeding 30 miles, including at least one run longer than 9 miles) demonstrated significantly enhanced emotion regulation after 90 minutes of running. Those who regularly exercise (three times per week, with each session lasting at least 45 minutes) exhibited reduced negative emotional responses and increased positive affect following high-intensity exercise (heart rate around 90–96% HRmax for 30 minutes). The emotional improvements elicited by intense aerobic exercise (88% HRmax for 24 minutes) were more pronounced among physically active individuals (training 3–4 times per week). This may be attributed either to a higher adaptation to exercise intensity within this group or to the possibility that their prefrontal cortex demands less metabolic support—a notion supported by lower cortical oxygenation levels during moderate-intensity exercise among these individuals. During high-intensity exercise, experienced exercisers maintain high prefrontal cortex oxygenation levels due to reduced influx of endoreceptive information, whereas in inexperienced individuals, oxygenation drops to near-resting levels.

Regularity

The mechanisms through which acute (single bout) and chronic (long-term) aerobic exercise affect emotion regulation exhibit both distinctions and intersections. Acute aerobic exercise increases arousal, cerebral activation, and connectivity, temporarily enhancing the synthesis and release of neurotransmitters and neurotrophic factors. This results in an immediate sense of well-being and reduced sensitivity to negative stimuli. It is noteworthy that the effects of acute exercise persist even after the end of activity; for example, increased neural activity in the fronto-parietal region can endure for up to 15 minutes post-exercise. However, these effects are ephemeral, as evidenced by the rapid decline in prefrontal cortex oxygenation shortly after exercise finished. Moreover, although aerobic exercise elevates levels of brain-derived neurotrophic factor (BDNF)—a molecule pivotal for emotional health—this increase is transient and reverts to baseline within 15 minutes post-exercise. Studies focusing on acute aerobic exercise typically assess emotion regulation performance immediately after the intervention; however, there is a lack of consensus regarding the precise time interval between the end of exercise and the commencement of the subsequent task or questionnaire. Thus, this narrative review cannot definitively ascertain the duration of the beneficial effects of aerobic exercise. Based on the duration of emotion regulation tasks and changes in endocrine and neural activity, it is plausible to assume that these benefits persist for at least 20 minutes. Additionally, studies on emotion regulation performance during acute exercise remain scarce.

Neuro-modulatory changes and alterations in neural activity induced by a single session of aerobic exercise are sustained and consolidated over time. An increased frequency of exercise sessions leads to homeostatic adaptations and plastic changes in the human brain. Chronic aerobic exercise exerts a more stable influence on emotion regulation. Typically, evaluations in long-term intervention studies are not conducted immediately after the last exercise session to avoid confounding acute effects. Research has indeed demonstrated a strong correlation between long-term aerobic exercise and improvements in cognitive reappraisal capabilities. Chronic exercise enhances brain plasticity, for instance, by increasing connectivity within networks associated with the hippocampus and amygdala, improving the integrity of white matter tracts connecting the prefrontal cortex and amygdala, and elevating dopamine levels in the medial prefrontal cortex—an essential component for emotion regulation. Furthermore, long-term exercise confers neuroprotective effects, resulting in lower cortisol levels during stress and fewer difficulties in daily emotion regulation.

Summary

In summary, aerobic exercise plays a significant role in the regulation of emotions, influencing various aspects of mental health. A regular exercise, particularly at moderate intensities, can substantially enhance mood, reduce stress, and strengthen the ability to cope with negative emotions. Moreover, long-term engagement in physical activity leads to enduring changes in brain plasticity, further supporting daily emotion regulation. A comprehensive understanding of these mechanisms is critical not only for advancing scientific knowledge but also for informing clinical practice, where aerobic exercise can be effectively integrated as an adjunctive therapeutic strategy in the treatment of psychiatric disorders.

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