The fact that a single bout of acute physical exercise has a positive impact on cognition is well-established in the literature, but the neural correlates that underlie these cognitive improvements are not well understood. Here, the use of neuroimaging techniques, such as functional magnetic resonance imaging (fMRI), offers great potential, which is just starting to be recognized. This review aims at providing an overview of those studies that used fMRI to investigate the effects of acute physical exercises on cerebral hemodynamics and cognition. To this end, a systematic literature survey was conducted by two independent reviewers across five electronic databases. The search returned 668 studies, of which 14 studies met the inclusion criteria and were analyzed in this systematic review. Although the findings of the reviewed studies suggest that acute physical exercise (e.g., cycling) leads to profound changes in functional brain activation, the small number of available studies and the great variability in the study protocols limits the conclusions that can be drawn with certainty. In order to overcome these limitations, new, more well-designed trials are needed that (i) use a more rigorous study design, (ii) apply more sophisticated filter methods in fMRI data analysis, (iii) describe the applied processing steps of fMRI data analysis in more detail, and (iv) provide a more precise exercise prescription.

This systematic review and meta-analysis aimed to examine the effects of eccentric resistance training (ERT) versus traditional resistance training (TRT) on muscle strength, power, hypertrophy, and functional capacity in healthy older adults. Eleven randomized-controlled-trials were included. Between-group analysis for strength demonstrated a small but significant effect in favour of ERT over TRT (standardized-mean-difference [SMD]=0.27). No significant differences were found for functional capacity (SMD=0.12), muscle power (SMD=0.20), or hypertrophy (SMD=-0.03). Within-group analyses for ERT indicated large, significant effects for strength (SMD=0.96) and functional capacity (SMD=1.09) with no significant effects for power and hypertrophy. For TRT, large and moderate significant effects were found for functional capacity (SMD=0.94) and strength (SMD=0.59), respectively, with no significant effects for power and hypertrophy. Meta-regression analysis indicated that longer intervention durations were approaching-significance in their association with greater muscle strength gains with ERT than TRT (p = 0.09). With ERT, increasing age was significantly associated with greater muscle power gains (p = 0.04) and more sessions were approaching-significance in their association with hypertrophy (p = 0.08). Regarding TRT, a higher proportion of female participants was approaching-significance in its association with greater functional capacity gains (p = 0.09). In summary, ERT yields slightly greater muscle strength gains than TRT in older adults, while both produced comparable effects on functional capacity, muscle power, and hypertrophy. The two training modalities elicit moderate-to-large within-group improvements in strength and functional capacity but not in power or hypertrophy. ERT outcomes appear to be moderated by training duration, session number, and age, whereas TRT effects relate to female proportion. Overall, both modalities are effective for older adults, with a slight strength advantage for ERT.

The mechanisms subserving motor skill acquisition and learning in the intact human brain are not fully understood. Previous studies in animals have demonstrated a causal relationship between motor learning and structural rearrangements of synaptic connections, raising the question of whether neurite-specific changes are also observable in humans. Here, we use advanced diffusion magnetic resonance imaging (MRI), sensitive to dendritic and axonal processes, to investigate neuroplasticity in response to long-term motor learning. We recruited healthy male and female human participants (age range 19–29) who learned a challenging dynamic balancing task (DBT) over four consecutive weeks. Diffusion MRI signals were fitted using Neurite Orientation Dispersion and Density Imaging (NODDI), a theory-driven biophysical model of diffusion, yielding measures of tissue volume, neurite density and the organizational complexity of neurites. While NODDI indices were unchanged and reliable during the control period, neurite orientation dispersion increased significantly during the learning period mainly in primary sensorimotor, prefrontal, premotor, supplementary, and cingulate motor areas. Importantly, reorganization of cortical microstructure during the learning phase predicted concurrent behavioral changes, whereas there was no relationship between microstructural changes during the control phase and learning. Changes in neurite complexity were independent of alterations in tissue density, cortical thickness, and intracortical myelin. Our results are in line with the notion that structural modulation of neurites is a key mechanism supporting complex motor learning in humans.SIGNIFICANCE STATEMENTThe structural correlates of motor learning in the human brain are not fully understood. Results from animal studies suggest that synaptic remodeling (e.g., reorganization of dendritic spines) in sensorimotor-related brain areas is a crucial mechanism for the formation of motor memory. Using state-of-the-art diffusion magnetic resonance imaging (MRI), we found a behaviorally relevant increase in the organizational complexity of neocortical microstructure, mainly in primary sensorimotor, prefrontal, premotor, supplementary, and cingulate motor regions, following training of a challenging dynamic balancing task (DBT). Follow-up analyses suggested structural modulation of synapses as a plausible mechanism driving this increase, while colocalized changes in cortical thickness, tissue density, and intracortical myelin could not be detected. These results advance our knowledge about the neurobiological basis of motor learning in humans.

Athletic features distinguishing experts from non-experts in team sports are relevant for performance analyses, talent identification and successful training. In this respect, perceptual-cognitive factors like decision making have been proposed to be important predictor of talent but, however, assessing decision making in team sports remains a challenging endeavor. In particular, it is now known that decisions expressed by verbal reports or micro-movements in the laboratory differ from those actually made in on-field situations in play. To address this point, our study compared elite and amateur players’ decision-making behavior in a near-game test environment including sport-specific sensorimotor responses. Team-handball players (N = 44) were asked to respond as quickly as possible to representative, temporally occluded attack sequences in a team-handball specific defense environment on a contact plate system. Specifically, participants had to choose and perform the most appropriate out of four prespecified, defense response actions. The frequency of responses and decision time were used as dependent variables representing decision-making behavior. We found that elite players responded significantly more often with offensive responses (p < 0.05, odds ratios: 2.76–3.00) in left-handed attack sequences. Decision time decreased with increasing visual information, but no expertise effect was found. We suppose that expertise-related knowledge and processing of kinematic information led to distinct decision-making behavior between elite and amateur players, evoked in a domain-specific and near-game test setting. Results also indicate that the quality of a decision might be of higher relevance than the required time to decide. Findings illustrate application opportunities in the context of performance analyses and talent identification processes.

Age-related deterioration in postural control is an important factor decreasing quality of life. Functional neuroimaging studies have shown that the activation of the prefrontal cortex (PFC) during balancing is typically higher in older (OA) compared to younger adults (YA), probably reflecting a mechanism contributing to worsened balance control with aging. Here, we hypothesized that balance training (BAL) shifts PFC activation towards a more efficient pattern, enabling improved balance performance. To test this hypothesis, we conducted a randomized controlled trial with healthy older (65-80 y) and young adults (18-35 y) of both sexes (n = 63) comparing the effects of a 6-month BAL intervention (1 h of BAL twice weekly) against age-matched, non-BAL controls (CON). In both age groups, we found that BAL led to a significant reduction in sway in trained and untrained balance tasks compared to CON, which could still be observed 6 months after the end of training (multivariate p's < .003). In OA, we found a larger reduction in PFC activation assessed with functional near-infrared spectroscopy in BAL compared to CON after training (multivariate p < .02), and a similar yet not significant trend was observed in YA (p < .06). Importantly, in OA, both cross-sectional correlations and longitudinal correlated changes showed that reduced PFC activation was associated with better balance performance. Our results support the idea that BAL may reduce dysfunctional PFC activation in OA, resulting in activation patterns more similar to those of YA, with positive effects on postural control and possibly fall risk.