Exercise and microstructural changes in the motor cortex of older adults.

Exercise has been shown to counteract age-related volume decreases in the human brain, and in this imaging study, we ask whether the same holds true for the microstructure of the cortex. Healthy older adults (n = 47, 65-90 years old) either exercised three times a week on a stationary bike or maintained their usual physical routine over a 12-week period. Quantitative longitudinal relaxation rate (R1 ) magnetic resonance imaging (MRI) maps were made at baseline and after the 12-week intervention. R1 is commonly taken to reflect cortical myelin density. The change in R1 (ΔR1 ) was significantly increased in a region of interest (ROI) in the primary motor cortex containing motor outputs to the leg musculature in the exercise group relative to the control group (p = .04). The change in R1 in this ROI correlated with an increase in oxygen consumption at the first ventilatory threshold (VT1) (p = .04), a marker of improvement in submaximal aerobic performance. An exploratory analysis across the cortex suggested that the correlation was predominately confined to the leg representation in the motor cortex. This study suggests that microstructural declines in the cortex of older adults may be staved off by exercise.

Preventive Effects of a Single Bout of Exercise on Memory and Attention following One Night of Sleep Loss in Sports Students: Results of a Randomized Controlled Study.

Sleep loss is a severe problem in night-shift workers. It causes fatigue and a decrease in awareness that may be counter-acted by exercise. This randomized controlled study of 22 university students investigated the effects of exercise to prevent loss of cognitive and physical performance following sleep deprivation. We compared a single bout of 20 min circuit training to control in an experimental setting of overnight sleep loss. Outcomes included memory, cognitive tasks, and physical parameters. The occurrence of false memories was considered the main outcome. Exercise did not exert significant effects on false memories (p = 0.456). We could detect a trend to significance (p < 0.01) assessing cognitive dimensions, i.e., selective and sustained attention, and visual scanning speed. This revealed strong effects of exercise on attention (p = 0.091; Cohen's d = 0.76; ∆14%), cognitive performance, performance speed, and perceived sleepiness (p = 0.008; d = 0.60; ∆2.4 cm VAS). This study failed to show the effects of exercise on memory function. Still, the observed effects on attention and consciousness could be considered clinically relevant, as these results encourage further research to determine its practicability and meaningfulness among night-shift workers.

Deducing the Impact of Physical Activity, Sedentary Behavior, and Physical Performance on Cognitive Function in Healthy Older Adults.

Objectives: Participating in physical activity and maintaining physical performance as well as reducing sedentary behavior are discussed to be beneficially associated with cognitive function in older adults. The purpose of this cross-sectional analysis was to differentiate the relevance of objectively measured physical activity, physical performance, and sedentary behavior on cognitive function in healthy older adults (n = 56, age = 76 ± 7 yrs, gender = 30 female). Methods: Accelerometer based physical activity and sedentary behavior were analyzed as minutes per week spent sedentary and physically active with light or moderate to vigorous intensity. Participants' physical performance was assessed via cardiopulmonary exercise testing and analyzed as maximal workload and heart rate, heart rate reserve and peak oxygen uptake. The assessment of cognitive function included working memory, attention, executive function, and verbal memory. Data was analyzed with Spearman and partial correlations. Trial registration: NCT02343029. Results: Light physical activity was moderately associated with executive function (r = -0.339, p = 0.015). Attention was significantly associated with maximal workload (r = -0.286, p = 0.042) and peak oxygen uptake (r = -0.337, p = 0.015). Working memory was associated with maximal workload (r = 0.329, p = 0.017). Conclusion: Whereas a broad range of cognitive function were beneficially linked to physical performance, light intensity activities in particular showed an impact on executive function. Our research underlines the need to separate the impact of physical performance and physical activity on cognitive function and highlights the relevance of light physical activity.

Explaining Upper or Lower Extremity Crossover Effects of Visuomotor Choice Reaction Time Training.

Current evidence indicates a strong relation between improved visuomotor choice reaction time (VMRT) and a reduced risk of lower extremity injury, making both lower- and upper extremity VMRT training paradigms valuable to athletes. This investigation studied as yet unconfirmed crossover effects of upper extremity training on lower extremity performance; and we evaluated underlying relevant perceptual and cognitive adaptations. In this three-armed, randomized, controlled intervention, we used a computerized training device to compare participants receiving four weeks of upper (n = 12) and lower (n = 12) extremity VMRT training with a control group (n = 13) of healthy participants. Collectively, our participants had a mean age of 24.6 years (SD = 2.2), a mean height of 173 cm (SD = 10), and a mean weight of 69.6 kg (SD = 12.1); 57% (n = 21) were female and 43% (n = 16) were male. We assessed participants' upper and lower extremity VMRT performance and domain-specific perceptual and cognitive abilities before and after intervention and analyzed differences between their before and after performances. Lower extremity training enhanced VMRT performances for both lower extremity and crossover upper extremity. Upper extremity training improved VMRT for upper extremity and increased cognitive choice reaction performance but yielded no crossover effects to lower extremity. We found no effects of VMRT training on other domain-specific cognitive performance markers (attention, executive function, memory, or working memory). VMRT training modulated only task-specific cognitive performance and induced crossover effects from lower extremity training to upper extremity performance but not vice versa.