Exercising the Sleepy-ing Brain: Exercise, Sleep, and Sleep Loss on Memory.

We examine the novel hypothesis that physical exercise and sleep have synergistic effects on memory. Exercise can trigger mechanisms that can create an optimal brain state during sleep to facilitate memory processing. The possibility that exercise could counteract the deleterious effects of sleep deprivation on memory by protecting neuroplasticity also is discussed.

Pulmonary Rehabilitation does not Improve Objective Measures of Sleep Quality in People with Chronic Obstructive Pulmonary Disease.

Abnormal sleep duration is associated with poor health. Upwards of 50% of people with chronic obstructive pulmonary disease (COPD) report poor sleep quality. The effect of pulmonary rehabilitation on self-reported sleep quality is variable. The aim of this study was to assess the effect of pulmonary rehabilitation on objectively measured sleep quality (via actigraphy) in people with COPD. Sleep quality was assessed objectively using the SenseWear Armband (SWA, BodyMedia, Pittsburgh, PA), worn for ≥4 days before and immediately after completing an 8-week pulmonary rehabilitation program. Sleep characteristics were derived from accelerometer positional data and registration of sleep state by the SWA, determined from energy expenditure. Forty-eight participants (n = 21 male) with COPD (mean (SD), age 70 (10) years, mean FEV1 55 (20) % predicted, mean 45 (24) pack year smoking history) contributed pre and post pulmonary rehabilitation sleep data to this analysis. No significant differences were seen in any sleep parameters after pulmonary rehabilitation (p = 0.07-0.70). There were no associations between sleep parameters and measures of quality of life or function (all p > 0.30). Sleep quality, measured objectively using actigraphy, did not improve after an 8-week pulmonary rehabilitation program in individuals with COPD. Whether on-going participation in regular exercise training beyond the duration of pulmonary rehabilitation may influence sleep quality, or whether improving sleep quality could enhance rehabilitation outcomes, is yet to be determined.

Motor Memory Consolidation Deficits in Parkinson's Disease: A Systematic Review with Meta-Analysis.

BACKGROUND: The ability to encode and consolidate motor memories is essential for persons with Parkinson's disease (PD), who usually experience a progressive loss of motor function. Deficits in memory encoding, usually expressed as poorer rates of skill improvement during motor practice, have been reported in these patients. Whether motor memory consolidation (i.e., motor skill retention) is also impaired is unknown. OBJECTIVE: To determine whether motor memory consolidation is impaired in PD compared to neurologically intact individuals. METHODS: We conducted a pre-registered systematic review (PROSPERO: CRD42020222433) following PRISMA guidelines that included 46 studies. RESULTS: Meta-analyses revealed that persons with PD have deficits in retaining motor skills (SMD = -0.17; 95% CI = -0.32, -0.02; p = 0.0225). However, these deficits are task-specific, affecting sensory motor (SMD = -0.31; 95% CI -0.47, -0.15; p = 0.0002) and visuomotor adaptation (SMD = -1.55; 95% CI = -2.32, -0.79; p = 0.0001) tasks, but not sequential fine motor (SMD = 0.17; 95% CI = -0.05, 0.39; p = 0.1292) and gross motor tasks (SMD = 0.04; 95% CI = -0.25, 0.33; p = 0.7771). Importantly, deficits became non-significant when augmented feedback during practice was provided, and additional motor practice sessions reduced deficits in sensory motor tasks. Meta-regression analyses confirmed that deficits were independent of performance during encoding, as well as disease duration and severity. CONCLUSION: Our results align with the neurodegenerative models of PD progression and motor learning frameworks and emphasize the importance of developing targeted interventions to enhance motor memory consolidation in PD.

Does Cardiorespiratory Fitness Protect Memory from Sleep Deprivation?

INTRODUCTION: Animal studies have demonstrated that physical exercise can protect memory from the effects of sleep deprivation (SD). We examined whether having a high cardiorespiratory fitness (V̇O 2peak ) is associated with an enhanced capacity to encode episodic memory after one night of SD. METHODS: Twenty-nine healthy young participants were allocated into either an SD group ( n = 19) that underwent 30 h of uninterrupted wakefulness, or a sleep control (SC) group ( n = 10) that followed a regular sleep routine. Following either the SD or SC period, participants were asked to view 150 images as the encoding part of the episodic memory task. Ninety-six hours after viewing the images, participants returned to the laboratory to perform the recognition part of the episodic memory task, which required the visual discrimination of the 150 images previously presented from 75 new images introduced as distractors. Cardiorespiratory fitness (V̇O 2peak ) was assessed with a bike ergometer graded exercise test. Group differences in memory performance were assessed with independent t tests and associations between V̇O 2peak and memory with multiple linear regression. RESULTS: The SD group showed a significant increase in subjective fatigue (mean difference [MD] [standard error {SE}] = 38.94 [8.82]; P = 0.0001) and a worse capacity to identify the original 150 images (MD [SE] = -0.18 [0.06]; P = 0.005) and discriminate them from distractors (MD [SE] = -0.78 [0.21] P = 0.001). When adjusted for fatigue, higher V̇O 2peak was significantly associated with better memory scores in the SD (R 2 = 0.41; ß [SE] = 0.03 [0.01]; P = 0.015) but not in the SC group ( R2 = 0.23; ß [SE] = 0.02 [0.03]; P = 0.408). CONCLUSIONS: These results confirm that SD before encoding impairs the capacity to create robust episodic memories and provide preliminary support to the hypothesis that maintaining high levels of cardiorespiratory fitness could have a protective effect against the disruptive effects of sleep loss on memory.

Diurnal Physical Activity Patterns in Patients With Chronic Obstructive Pulmonary Disease.

PURPOSE: People with chronic obstructive pulmonary disease (COPD) have reduced physical activity (PA) levels compared with healthy controls. The pattern of their PA level during the day is much less documented. A better understanding of these diurnal PA patterns could help optimize interventions targeting PA levels in this population. The aim of this study was to examine, in patients with COPD, diurnal PA patterns using accelerometer data and different approaches to data handling (arbitrary, mealtime, equal tertiles). METHODS: Fourteen COPD patients (aged 71 ± 9 yr; forced expiratory volume in 1 sec [FEV1]: 58% ± 13% predicted) completed the study. Daily PA was assessed via accelerometry for 7 d, 24 hr/d. Diurnal PA patterns were evaluated using an arbitrary (08:00-12:00, 12:01-16:00, 16:01-20:00), mealtime (wake time-lunchtime, lunchtime-suppertime, suppertime-bedtime), and equal tertiles (tertiles 1, 2, and 3) approaches. Results were interpreted on the basis of descriptive statistics and effect sizes (Cohen f) for time-of-day changes in PA. RESULTS: Regardless of the handling approach used, mean PA levels decreased in the evening and the effect size for time-of-day changes in PA level was large (f = 0.97; 1.82; and 1.66 for the arbitrary, mealtimes, and tertiles approaches, respectively). The observation of a decrease in the evening was highly homogeneous across our sample, particularly with the mealtime and equal tertiles handling approach. CONCLUSION: Results from this study support prior findings that PA levels decrease substantially in the evening in patients with COPD, thereby providing a better understanding of within-day PA behavior and offering valuable insight into interventions targeting PA.

Diurnal Variations in Psychological Distress in Chronic Obstructive Pulmonary Disease.

PURPOSE: The aim of this study was to investigate the association between depressive symptoms severity and amplitude of diurnal variations in depression symptoms in patients with chronic obstructive pulmonary disease (COPD). DESIGN: Prospective, observational proof-of-concept study. METHODS: Fourteen participants with moderate/severe COPD completed a 20-item Center for Epidemiologic Studies Depression Scale (CES-D) estimating depressive symptoms severity. Throughout one week, the four-item very short version of the CES-D was completed every day in the morning, afternoon, and evening. FINDINGS: Strong positive correlations were observed between depressive severity and the mean range of diurnal variations in positive (r = .61) and depressed affects (r = .67), somatic complaints (r = .82), and disturbed interpersonal relationships (r = .71). CONCLUSION: In COPD patients, a greater diurnal variation in depression symptoms was associated with greater depression severity. This relationship seems independent of COPD severity. CLINICAL RELEVANCE: Diurnal variation in the symptoms of depression is a new method of identifying depression severity in COPD.