Acute Exercise Prevents Angry Mood Induction But Does Not Change Angry Emotions

Nathaniel J. Thom; Patrick J. O'Connor; Brett A. Clementz; Rod K. Dishman

Disclosures

Med Sci Sports Exerc. 2019;51(7):1451-1459. 

In This Article

Abstract and Introduction

Abstract

Introduction: Exercise is well known to enhance a variety of mood states, but few studies have been specifically designed to investigate whether acute aerobic exercise alters feelings of anger. The goal of this study was to determine the magnitude of the effects of acute exercise on both angry mood and angry emotions.

Methods: Angry mood and angry emotions were assessed in 16 men with elevated trait anger who viewed a variety of emotionally evocative scenic pictures before and after 30 min of moderate- to vigorous-intensity aerobic exercise. Angry mood, captured by self-reports of state anger, angry emotions, as indexed by event-related brain activity (e.g., early posterior negativity and late positive potential), and self-reports of anger intensity were measured.

Results: The results indicate that acute exercise both 1) reduces angry mood and 2) mitigates angry mood induction but does not change the intensity of angry emotions or the associated event-related potential responses to anger-inducing pictures in college-age men who have elevated trait anger.

Conclusion: Future studies should explore the mechanisms underlying the effect of exercise on preventing angry mood induction, consider alternative anger induction methods that might induce higher levels of angry emotions, and test the effects of chronic exercise training on anger and its expression.

Introduction

Extensive evidence suggests that exercise enhances pleasant affect and ameliorates negative moods, including tension, anxiety, and depression, and people report that exercise is one of the most common approaches they take to manage their mood. By contrast, very few studies have tested whether acute exercise alters emotional processing, a mood-related construct. Moods tend to be longer-lasting cognitive states with no antecedent event nor any neurophysiological correlates, whereas emotions tend to be of shorter duration with a specific causal triggering event and measurable neurophysiology.[1] Although there are a few studies that have evaluated the effects of acute exercise on general emotional processing,[2–4] we are unaware of any studies that have evaluated both angry mood and emotions in men with high levels of trait anger, despite the considerable burden of anger on public health and welfare.[5] For example, anger is associated with acts of violence and aggression[6] as well as elevated odds of hypertension,[7] cardiovascular disease,[8] and cardiovascular events.[9] Angry mood and emotions are regulated by limbic and frontal brain regions that can be altered by acute exercise.[10] Therefore, it is plausible that acute exercise could reduce anger by altering activity in neural circuits that control mood and emotion. The purpose of this study was to investigate the effects of acute moderate-intensity aerobic exercise on angry mood, and brain and behavioral correlates of angry emotional responses in a sample of high trait anger, college-age men.

Different types of studies suggest that exercise could reduce angry mood. Cross-sectional studies found an inverse relation between angry mood and exercise session duration, especially in men,[11] and those individuals who exercise more than twice a week experience less anger.[12] A review of experimental and quasi-experimental studies on the effects of acute exercise on mood found that a bout of exercise is accompanied by a moderate reduction in state anger (Thom, unpublished observations, August 2009). Most of those studies were not conducted for the purpose of evaluating anger outcomes of acute exercise; therefore, most study participants had low levels of trait or state anger before exercise. However, it is likely that reductions in anger after acute exercise would be more pronounced after evoking anger, or in high trait anger individuals, as is the case with anxiety.[13] Also, most of the studies evaluated did not attempt to manipulate anger, which precludes causal inferences about reductions in anger after exercise. One study that did manipulate anger used guided imagery to induce an upset/angry mood and reported a reduction in state anger after a bout of resistance exercise.[14] The implications of those results are limited, however, because the reduction in anger after exercise was of the same magnitude as in the control group. Furthermore, many of the studies used the anger–hostility scale of the Profile of Mood States to measure angry mood, but that scale was designed to measure the intensity of the mood of anger and does not differentiate between the experience and the expression of anger. By contrast, the State-Trait Anger Expression Inventory 2 (STAXI-2) was designed to separate anger from hostility and aggression as well as measure the experience and expression of anger.[15] Another methodological limitation of a majority of the studies was the sole use of self-report outcomes, which are vulnerable to experimenter and subject expectancy effects. An alternative, and potentially stronger, methodology would include measuring a physiological index of anger to provide objective complementary or convergent evidence for self-reports. Although moods do not produce marked physiological changes, emotions do. Therefore, it would be possible to measure a physiological index of anger by evoking angry emotions. Because angry emotions are regulated by several limbic system structures and the prefrontal cortex, studies designed to test the effects of exercise on angry emotions could benefit from concurrently measuring changes in relevant brain activity.

Electroencephalography (EEG) has been widely used to measure brain activity during emotion, and oscillatory and event-related brain dynamics can be measured as correlates of emotional processing. Event-related potentials (ERP) are linked to functional hemodynamics during emotional processing and are therefore a precise measure of brain activity during emotion processing.[16] Numerous studies have measured ERP during emotion and have found that the amplitude of several components (e.g., early posterior negativity [EPN] and late positive potential [LPP]) is altered while participants view arousing emotional stimuli (for a review, see Schupp et al.[17]). In short, middle-latency components like the EPN are altered by the emotional content of scenic pictures, such that highly arousing pleasant and unpleasant pictures result in greater EPN amplitude, indexing selective attention.[18] In addition, the LPP has been linked to the process of encoding relevant stimuli into working memory[19] and is also altered by the emotional valence and arousal level of evocative pictures.[20] EPN and LPP are the most widely studied ERP indices of emotional processing. To our knowledge, no studies have measured ERP correlates of angry emotions after exercise, but one study did show reduced self-reported arousal to unpleasant pictures after acute aerobic exercise,[2] suggesting that unpleasant emotional stimuli are processed differently by the brain after a single bout of aerobic exercise.

In this study, we assessed angry mood and emotions in men with elevated trait anger before and after 30 min of quiet rest or moderate-intensity aerobic cycling exercise. The goal of this study was to determine the magnitude of the effects of acute exercise on angry mood and on anger-associated brain and behavioral responses to emotionally evocative stimuli. The main hypotheses were that an acute bout of exercise would 1) reduce postexercise anger mood state and 2) reduce the intensity of angry emotions and the associated EPN and LPP amplitude during the viewing of anger-evoking pictures.

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