Neural consequences of post-exertion malaise in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.

Post exertion malaise is one of the most debilitating aspects of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome, yet the neurobiological consequences are largely unexplored. The objective of the study was to determine the neural consequences of acute exercise using functional brain imaging. Fifteen female Myalgic Encephalomyelitis/Chronic Fatigue Syndrome patients and 15 healthy female controls completed 30min of submaximal exercise (70% of peak heart rate) on a cycle ergometer. Symptom assessments (e.g. fatigue, pain, mood) and brain imaging data were collected one week prior to and 24h following exercise. Functional brain images were obtained during performance of: 1) a fatiguing cognitive task - the Paced Auditory Serial Addition Task, 2) a non-fatiguing cognitive task - simple number recognition, and 3) a non-fatiguing motor task - finger tapping. Symptom and exercise data were analyzed using independent samples t-tests. Cognitive performance data were analyzed using mixed-model analysis of variance with repeated measures. Brain responses to fatiguing and non-fatiguing tasks were analyzed using linear mixed effects with cluster-wise (101-voxels) alpha of 0.05. Myalgic Encephalomyelitis/Chronic Fatigue Syndrome patients reported large symptom changes compared to controls (effect size ≥0.8, p<0.05). Patients and controls had similar physiological responses to exercise (p>0.05). However, patients exercised at significantly lower Watts and reported greater exertion and leg muscle pain (p<0.05). For cognitive performance, a significant Group by Time interaction (p<0.05), demonstrated pre- to post-exercise improvements for controls and worsening for patients. Brain responses to finger tapping did not differ between groups at either time point. During number recognition, controls exhibited greater brain activity (p<0.05) in the posterior cingulate cortex, but only for the pre-exercise scan. For the Paced Serial Auditory Addition Task, there was a significant Group by Time interaction (p<0.05) with patients exhibiting increased brain activity from pre- to post-exercise compared to controls bilaterally for inferior and superior parietal and cingulate cortices. Changes in brain activity were significantly related to symptoms for patients (p<0.05). Acute exercise exacerbated symptoms, impaired cognitive performance and affected brain function in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome patients. These converging results, linking symptom exacerbation with brain function, provide objective evidence of the detrimental neurophysiological effects of post-exertion malaise.

Cognitive Resilience and Psychological Responses across a Collegiate Rowing Season.

INTRODUCTION: Student-athletes face numerous challenges across their competitive season. Although mood states have been previously studied, little is known about adaptations in other psychological responses, specifically cognition. The purpose of this study was to characterize cognitive function, mood, sleep, and stress responses at select time points of a season in collegiate rowers. It was hypothesized that during baseline, typical training, and recovery, athletes would show positive mental health profiles, in contrast to decreases in cognition with increases in negative mood and measurements of stress during peak training. METHODS: Male and female Division I rowers (N = 43) and healthy controls (N = 23) were enrolled and assessed at baseline, typical training, peak training, and recovery. At each time point, measures of cognitive performance (Stroop color-naming task), academic and exercise load, perceived cognitive deficits, mood states, sleep, and stress (via self-report and salivary cortisol) were recorded. RESULTS: Repeated-measures ANOVA revealed significant group-time interactions for perceived exercise load, cognitive deficits, mood states, and perceived stress (P < 0.05). For athletes during peak training, the perception of cognitive deficits was positively correlated with mood disturbance (r = 0.54, P < 0.05) and perceived stress (r = 0.55, P < 0.05) and negatively correlated with response accuracy during incongruent Stroop trials (r = -0.38, P < 0.05). Cognitive performance did not change over the course of the season for either group. Cortisol and sleepiness changed over the course of the season but no significant interactions were observed. CONCLUSION: These results demonstrate that various psychological responses change over the course of a season, but they also highlight adaptation indicative of cognitive resilience among student-athletes.

Physical activity, sustained sedentary behavior, and pain modulation in women with fibromyalgia.

UNLABELLED: Fibromyalgia (FM) has been conceptualized as a disorder of the central nervous system, characterized by augmented sensory processing and an inability to effectively modulate pain. We previously reported that physical activity is related to brain processing of pain, providing evidence for a potential mechanism of pain management. The purpose of this study was to extend our work by manipulating pain modulation and determining relationships to both physical activity and sustained sedentary behavior. Eleven women with FM completed accelerometer measures of physical activity and underwent functional magnetic resonance imaging of painful heat, administered alone and during distracting cognitive tasks. Results showed that physical activity was significantly (P < .005) and positively related to brain responses during distraction from pain in regions implicated in pain modulation including the dorsolateral prefrontal cortex (DLPFC), the dorsal posterior cingulate, and the periaqueductal grey. A significant negative relationship occurred in the left anterior insula. For sedentary time, significant negative relationships were observed in areas involved in both pain modulation and the sensory-discriminative aspects of pain including the DLPFC, thalamus, and superior frontal and pre- and post-central gyri. These results suggest that physical activity and sedentary behaviors are related to central nervous system regulation of pain in FM. PERSPECTIVE: Our results support a promising benefit of physical activity and highlight the potentially deleterious effects of sustained sedentary behavior for pain regulation in FM. Studies aimed at increasing physical activity or reducing sedentary behavior and determining the impact of these on pain regulation are warranted.

Visual threat detection during moderate- and high-intensity exercise.

The aim of the study was to assess performance on a visual threat-detection task during concurrently performed vigorous exercise on a cycle ergometer. Thirty (15 female) participants completed a baseline condition of seated rest and then moderate- and high-intensity exercise. Moderate- and high-intensity exercise conditions were completed on the 2nd day in a counterbalanced order. During each exercise condition, participants responded to 3 × 3 picture matrices (256 trials in each condition) that contained discrepant fear-relevant and discrepant fear-irrelevant pictures (Öhman, Flykt, & Esteves, 2001). Response accuracy was significantly greater, and reaction time was significantly faster, during moderate- and high-intensity exercise compared with the rest condition (ps < .001). The discrepant fear-relevant matrix type was detected significantly more accurately than a discrepant fear-irrelevant matrix (p < .001). The discrepant fear-relevant matrix was detected significantly faster than all other matrix types (p < .001). These results suggest that exercise at a moderate and high intensity may enhance the efficiency of visual detection of both threatening and nonthreatening targets.