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Age-related neurodegenerative disorders, like Alzheimer's or Parkinson's disease, are becoming a major issue to public health care. Currently, there is no effective pharmacological treatment to address cognitive impairment in these patients. Here, we aim to explore the role of exercise-induced trophic factor enhancement in the prevention or delay of cognitive decline in patients with neurodegenerative diseases. There is a significant amount of evidence from animal and human studies that links neurodegenerative related cognitive deficits with changes on brain and peripheral trophic factor levels. Several trials with elderly individuals and patients with neurodegenerative diseases report exercise induced cognitive improvements and changes on trophic factor levels including BDNF, IGF-I, among others. Further studies with healthy aging and clinical populations are needed to understand how diverse exercise interventions produce different variations in trophic factor signaling. Genetic profiles and potential confounders regarding trophic factors should also be addressed in future trials.

Depression is associated with decreased serotonin metabolism and functioning in the central nervous system, evidenced by both animal models of depression and clinical patient studies. Depression is also accompanied by decreased hippocampal neurogenesis in diverse animal models. Neurogenesis is mainly defined in dentate gyrus of hippocampus as well as subventricular zone. Moreover, hypothalamus, amygdala, olfactory tubercle, and piriform cortex are reported with evidences of adult neurogenesis. Physical exercise is found to modulate adult neurogenesis significantly, and results in mood improvement. The cellular mechanism such as adult neurogenesis upregulation was considered as one major mood regulator following exercise. The recent advances in molecular mechanisms underlying exercise-regulated neurogenesis have widen our understanding in brain plasticity in physiological and pathological conditions, and therefore better management of different psychiatric disorders.

Physical exercise is responsible for different metabolic and hemodynamic changes, including increased cerebral blood flow and perfusion. It is known that running increases vascular endothelial growth factor expression in the brain, which is critical for the anti-depressive effects of adult neurogenesis induced by physical exercise. Both animal and human studies revealed that neurovascular responses to physical exercise are well correlated to adult hippocampal neurogenesis and cognition improvement. Yet it is unknown if the increased blood perfusion to hippocampus is affecting the adult neurogenesis. Manipulating systemic blood pressure, or stimulating the cerebral blood flow with alternative measures, might provide useful tools to understand how much neurovascular plasticity contributes to the brain cognition enhancement by physical exercise. In addition, it will be interesting to examine the responses of brain cells (including neuron, glia and endothelia cells) to increased shear stress and oxygen load, to investigate the underlying molecular mechanisms.

Microbiota is a set of microorganisms resident in gut ecosystem that reacts to psychological stressful stimuli, and is involved in depressed or anxious status in both animals and human being. Interestingly, a series of studies have shown the effects of physical exercise on gut microbiota dynamics, suggesting that gut microbiota regulation might act as one mediator for the effects of exercise on the brain. Recent studies found that gut microbiota dynamics are also regulated by metabolism changes, such as through physical exercise or diet change. Interestingly, physical exercise modulates different population of gut bacteria in compared to food restriction or rich diet, and alleviates gut syndromes to toxin intake. Gut microbiota could as well contribute to the beneficial effects of exercise on cognition and emotion, either directly through serotonin signaling or indirectly by modulating metabolism and exercise performance.

Neuroscience is an emergent research field that comprises many multidisciplinary investigations, searches for explanations about the relationship between the body and the brain. Here, we will give a little summary of this field showing the main current findings. We discuss the lack of consistent data about the relationship among exercise for neurodegenerative diseases and psychiatric disorders, sports performance and rehabilitation, and therefore, the difficult to describe cause-effect associations or to describe in detail the neurobiological mechanisms underlying these associations.

The pathophysiology of depression is related to neurobiological changes that occur in the monoamine system, hypothalamic-pituitary-adrenal axis, neurogenesis system and the neuroimmune system. In recent years, there has been a growing interest in the research of the effects of exercise on brain function, with a special focus on its effects on brain-derived neurotrophic factor (BDNF), cortisol and other biomarkers. Thus, the aim of this study is to present a review investigating the acute and chronic effects of aerobic exercise on BDNF and cortisol levels in individuals with depression. It was not possible to establish an interaction between aerobic exercise and concentration of BDNF and cortisol, which may actually be the result of the divergence of methods, such as type of exercises, duration of the sessions, and prescribed intensity and frequency of sessions.

The aim of this study was investigate the effects of transcranial direct current stimulation (tDCS) on volume load and ratings of perceived exertion. Fifteen young healthy individuals, aged between 20 and 30 years in advanced strength training were recruited. Test and retest of the 10 maximum repetitions (10RM) were performed to determine the reliability of load used. Subjects performed 3 experimental conditions in a randomized, double-blinded crossover design: anodic stimulation (a-tDCS), cathodic stimulation (c-tDCS), and sham (2 mA for 20 minutes targeting the dorsolateral prefrontal cortex left). Immediately after the experimental conditions, subjects completed 1 set of maximum repetitions with 10RM load (volume load) and answered to OMNI-RES (poststimulation) (level of significance p ≤ 0.05). The volume load showed main effect for condition (F(2, 28) = 164.801; p < 0.001). In poststimulation, a-tDCS was greater than c-tDCS (p ≤ 0.001) and sham (p ≤ 0.001). For ratings of perceived exertion (OMNI-RES), the results showed main effect for condition (F(2, 28) = 9.768; p ≤ 0.05). In poststimulation, c-tDCS was greater than a-tDCS (p ≤ 0.05) and sham (p ≤ 0.05). We conclude that the use of a-tDCS may promote increase in volume load for the LP45 exercise. Moreover, higher volume loads are necessary to maximize muscle strength and anabolism. [ABSTRACT FROM AUTHOR]

This study examined whether a standardized visual assessment of squatting technique and core stability can predict injury. Male adolescent and collegiate Gaelic players (n = 627) were assessed using the alternative core/trunk stability push-up test and a developed scoring system for the overhead squat and single-leg squat (SLS) that examined both overall impression and segmental criteria. A single summative score from the overall impression scores of all 3 tests was calculated. Sustained injuries were examined over a season. Results indicated that the single summative score did not predict those that sustained a lower-extremity injury, trunk injury, or whole-body injury, and receiver operating characteristic curves were also unable to generate an optimal cutoff point for prediction. When segmental criteria were included in multivariate analyses, the tests were able to predict whole-body injury (p < 0.0001) and lower-extremity injury (p < 0.0001). However, although specificity was high (80.6%, 76.5%), sensitivity of the models was low (40.2%, 44.2%). The most common score was "good" for the overhead squat (46.4%) and SLS (47.6%), and "good" and "excellent" for the alternative core stability push-up test (33.5%, 49.1%), with "poor" core stability increasing the odds of sustaining a lower-extremity injury (odds ratio = 1.52 [0.92-2.51]). The findings suggest that although segmental scoring could be incorporated by strength and conditioning coaches and clinicians, they should be used predominantly as a preliminary screening tool to highlight players requiring a more thorough assessment. [ABSTRACT FROM AUTHOR]