Shifting Focus Down the Severity Spectrum – Can we Intervene Earlier with Exercise? Matthew Herring

The available evidence, including much of my own previous work, supports that acute and chronic exercise results in small-to-moderate reductions in anxiety among otherwise healthy adults, adults with a diverse range of chronic illnesses, and among patients with an anxiety and/or stress-related disorder.  Our and others’ work has supported that exercise training, including aerobic and resistance exercise training, can improve clinical severity and associated signs and symptoms among individuals with Generalized Anxiety Disorder (GAD) or Panic Disorder, and these improvements are comparable to the improvements found following other empirically-supported treatments, including pharmacological and behavioural therapies.

However, a question that continues to loom is where along the severity spectrum that exercise may elicit the strongest improvements.  Though the positive effects of exercise among individuals with a clinically diagnosed anxiety disorder are of clear importance, fortunately, the majority of the population is not walking around with an anxiety disorder.  There is a larger population than one would imagine, however, who report preclinical anxiety, or elevations in key symptoms which are known to increase the probability of developing a full blown anxiety disorder in the future.  To this end, some of my colleagues and I have begun to shift our focus down the severity spectrum to examine exercise responses among potentially very interesting populations who have preclinical levels of anxiety.

For example, our recently accepted paper that is In Press at Psychology of Sport and Exercise details the findings of an investigation of the acute effects of aerobic exercise on worry, state anxiety, and feelings of energy and fatigue among young adult women with elevated worry scores indicative of probable GAD.  Seventeen young women with Penn State Worry Questionnaire scores ≥45 (60±8) completed 30-min of treadmill running at 65%-85% heart rate reserve (%HRR) and 30-min of seated quiet rest in counterbalanced order.  Total exercise time for participants was ~36min with a mean of 30.3±0.16min in-zone minutes (i.e., 65%-85%HRR); participants exercised at ~73 %HRR.  Compared with quiet rest, acute exercise significantly improved worry engagement, state anxiety, and feelings of energy and fatigue.  Moderate to large reductions in state anxiety and feelings of fatigue and increases in feelings of energy.  Exercise-induced reductions in worry engagement were significantly larger among non-high trait anxious participants, and, compared to normal sleepers, quiet rest significantly increased feelings of fatigue among poor sleepers.

To our knowledge, this is the first experimental study to examine the effects of acute exercise on worry, state anxiety, and feelings of energy and fatigue among young women with indications of GAD.  Compared to 30 minutes of quiet rest, a single bout of aerobic exercise significantly improved worry engagement, state anxiety, and feelings of energy and fatigue, providing initial support for the positive effects of even acute exercise on these outcomes among young women with worry indicative of GAD.  The moderate to large magnitude of improvements is consistent with previously reported effects of acute exercise on mood states among healthy adults, young adults with persistent fatigue, adults with Multiple Sclerosis, and women with Major Depressive Disorder.

Interestingly, the findings also suggested that the worry engagement subscale of the Penn State Worry Questionnaire, or the sum score of items presented in the direction of pathological worry as opposed to reverse-worded items, may provide a psychometrically-sound, more sensitive measure of worry response to exercise when considered independent of absence of worry.  Moreover, the findings indicated that state anxiety and feelings of energy and fatigue actually significantly worsened in response to quiet rest.  These findings are consistent with recent evidence that showed elevated anxiety following ‘imposed’ sedentary behaviour among active adults.  We think it is plausible that quiet rest might serve as a cognitively-passive, imposed bout of sedentary behaviour that acutely worsens mood states in some individuals.

Overall, these findings provide initial support for even a single bout of exercise to improve outcomes among individuals with preclinical levels of GAD.  We still know very little about the most appropriate point along the severity spectrum at which exercise might elicit the strongest positive effects, but these preliminary findings support exercise effects among young adults with preclinical elevations in worry.

Based on these findings, our research group plan to continue an increased focus on exercise effects among young adults with preclinical anxiety, and plan to move down the age spectrum into adolescence in the not-so-distant future.  The findings of this most recent manuscript also encourage our planned investigation of factors associated with the positive effects of exercise, including objective measures of attentional biases (i.e., eye-tracking during processing of emotional stimuli), plausible biomarkers (e.g., serotonergic and inflammatory factors), and sleep, as well as the worsening of mood states during quiet rest, including cognitively-active and cognitively-passive sedentary behaviour, rumination, and poor sleep quality.  We also critically need additional information regarding the time course of changes in response to exercise, the most appropriate exercise dose to elicit the largest improvements, and how understudied exercise modes, like resistance exercise, affect outcomes among individuals with preclinical anxiety.  To this end, our research group will be continuing investigations into these areas in the coming months, while also beginning a series of studies focused on resistance exercise among individuals with preclinical GAD largely driven by doctoral student Brett Gordon in collaboration with Dr. Mark Lyons.

What is becoming clearer based on our preliminary findings and ongoing investigations is that even acute exercise may be beneficial for individuals with preclinical levels of anxiety known to increase likelihood of a future diagnosis of an anxiety disorder.   However, there is plenty of work to do.

For Further Information:

Read the journal publication “Acute exercise effects on worry, state anxiety, and feelings of energy and fatigue among young women with probable Generalized Anxiety Disorder: A pilot study” Here!

Matthew Herring is a Lecturer in Exercise Psychology in the PESS Department at the University of Limerick. View Matt’s profile Here!

Matt’s Email: matthew.herring@ul.ie

 

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