A Randomized Controlled Trial of the Effect of Aerobic Exercise Training on Feelings of Energy and Fatigue in Sedentary Young Adults with Persistent Fatigue

Abstract

Background: There is growing evidence that chronic exercise is a promising intervention for combating feelings of low energy and fatigue. Although groups with well-defined medical conditions (for example cancer and heart disease) or unexplained fatigue syndromes consistently have reported improved feelings of energy and fatigue after chronic exercise, relatively few exercise training studies have been conducted with people who report persistent fatigue yet neither have a medical condition nor reach diagnostic criteria for an unexplained fatigue syndrome. The purpose of this investigation was to use a randomized controlled design to examine the effects of 6 weeks of chronic exercise training on feelings of energy and fatigue in sedentary, healthy young adults reporting persistent fatigue. Methods: Thirty-six healthy, young adults who reported persistent feelings of fatigue were randomly assigned to a moderate-intensity exercise, low-intensity exercise or no treatment control group. Participants in each condition then visited the exercise laboratory on 18 occasions over a 6-week period. Exercise laboratory visits occurred 3 days per week. Vigor and fatigue mood state scores were obtained at the beginning of the third exercise session each week for 6 weeks. Aerobic fitness was measured before and after intervention. Results: The effect of 6 weeks of exercise training on feelings of fatigue was dependent on exercise intensity; however, the effect on feelings of energy was similar for both the low- and moderate-intensity conditions. The changes in feelings of energy and fatigue were independent of changes in aerobic fitness. Conclusions: Six weeks of low and moderate exercise training performed by sedentary adults without a well-defined medical condition or an unexplained fatigue syndrome but reporting persistent feelings of fatigue resulted in similarly beneficial effects on feelings of energy. The effects for symptoms of fatigue were moderated by exercise intensity, and the more favorable outcome was realized with low-intensity exercise. Changes in feelings of energy and fatigue following exercise training were unrelated to changes in aerobic fitness.

Active and Sedentary Behaviors Influence Feelings of Energy and Fatigue in Women

“…Recently, Dishman et al (12) examined whether changes in feelings of energy and fatigue following acute exercise after 6 wk of aerobic training were related to changes in brain activity as measured by electroencephalography. Results demonstrated that theta activity in the posterior portion of the brain accounted for approximately 50% of the improvement in mood immediately postexercise and that these improvements were unrelated to changes in aerobic fitness during the course of the training trial (40). These results support central nervous system contributions to changes in feelings of energy and fatigue associated with participation physical activity and further underscore that changes in fitness (i.e., high-intensity exercise) are not necessary for mental health benefits.…”

“…For example, Puetz et al (40) found that feelings of energy were increased by approximately 20% after 6 wk of low-intensity aerobic exercise training in sedentary adults. Typically, sedentary time is significantly and inversely related to low-intensity activity and weakly related to moderate and vigorous activity (22).…”

“…The mental health benefits of exercise are well documented (31,40), and there is promising evidence demonstrating that exercise has the potential to be a viable treatment for fatigue (41). Results from population-based studies are uniformly supportive of a positive dose-response relationship between self-reported participation in exercise and feelings of energy (6,27).…”

“…Results from population-based studies are uniformly supportive of a positive dose-response relationship between self-reported participation in exercise and feelings of energy (6,27). Studies involving both acute and chronic exercise interventions have also shown significant benefits for both energy and fatigue in individuals with persistent fatigue (12,(39)(40)(41). Exercise interventions in nonfatigued adults have been less conclusive with results, either demonstrating positive effects of exercise or no change (2,5).…”

Developmental Influences on Medically Unexplained Symptoms

“…If some of the MUS turn out to have developmental origins, these drugs may be appropriate to consider for their therapeutic potential in these patients. This hypothesis also may explain the effectiveness of such ‘central’ approaches to therapy as tricyclic antidepressants (which among other actions attenuate catecholaminergic output) [75,76,77,78], hypnosis [79, 80], effective doctor–patient communication [81], use of psychiatrists as consultants in the general practice setting [82], and various other psychological approaches to treatment [2,83,84,85,86,87,88] that might reduce the perception of threat in amenable patients. We also have successfully used an ‘environmental’ approach to therapy for cats with FIC [89]; EMGEX is one candidate mechanism for the effects of environmental enrichment [90].…”