Earticle

Mixed martial arts (MMA), a combat sport consisting of wrestling, box-ing, and martial arts, is a popular activity associated with danger and vi-olence. Of concern are the repetitive head impacts, both subconcussive and concussive, sustained by MMA athletes. The rules of MMA en-courage head strikes, but there was no formal concussion protocol in the Ultimate Fighting Championship (UFC) until 2021. Because the UFC was established less than 30 years, the long-term consequences of these repetitive concussive head blows are lacking. In this review, we focus on current literature sought to summarize the current knowledge of repetitive head impacts and concussions in MMA. The objectives were to outline (a) the rules of MMA; (b) the postconcussion protocol for UFC athletes; (c) current behavioral and biochemical diagnostic measures; (d) epidemiology and prevalence of concussion in MMA; (e) long-term effects of subconcussive repetitive head impacts; (f) biome-chanics of head impacts; and (g) considerations and research topics that warrant future research.

For humans, maternal old age means the age of 35 or older at the time of childbirth. Maternal metabolism not only affects the cognitive func-tion of the offspring, but also affects their physical and neurological de-velopment. This study aims to elucidate the effects of exercise training on spatial learning memory, neurogenesis, and apoptosis in the off-spring of old mice. Using mice, the offspring of old mothers showed im-paired spatial learning memory, decreased brain-derived neurotrophic factor and postsynaptic density protein 95 levels, suppressed neuro-genesis, and increased hippocampal apoptotic cell death. In contrast, the offspring of the old mothers had improved spatial learning memory, increased brain-derived neurotrophic factor and postsynaptic density protein 95 levels, increased neurogenesis, and decreased hippocampal apoptotic cell death when they received exercise training. The present results indicate that there is apparent spatial learning memory impair-ment among the offspring of old mothers, but by contrast, exercise can ameliorate spatial learning memory impairment. Exercise can be an ef-fective countermeasure against memory decline in the offspring of old mothers.

This study attempted to investigate the association between changes in the intestinal environment and the brain using a model that received aerobic exercise and microbiome transplantation. All mice were fed a diet containing 60% fat. For the obesity with nonexercise microbiome transplantation group, feces from donors that did not undergo exercise were administered. For the obesity with exercise microbiome trans-plantation group, feces from donors who underwent exercise were ad-ministered. Treadmill exercise started 16 weeks after the intake of the high fat feeding and continued for 24 weeks. The short-term memory and spatial learning memory were determined by step-down avoidance test and Morris water maze task, immunohistochemistry for glial fibril-lary acidic protein, western blot analysis for brain-derived neurotrophic factor and tropomyosin receptor kinase B were performed in the hippo-campus. Exercise was the most effective way to reduce obesity, im-prove memory function, suppress inflammation, and increase brain-de-rived neurotrophic factor expression. Intestinal microbiota transplanta-tion was the second most effective after exercise. However, there was no significant difference in the fecal microbiota transplant group ac-cording to whether or not exercise was performed.

The aim of this study was to investigate the effects of exercise and diet on mental status, insulin signaling pathway, serotonin synthesis, and microbiome in high-fat-induced obesity mice. Before the start of this experiment, obesity groups made obese mice by administering a high-fat diet containing 60% fat for 12 weeks. In the obesity with exercise group, after a high-fat diet for 12 weeks, exercise was performed with high-fat diet for 8 weeks. In the obesity with diet group, a high-fat diet for 12 weeks followed by a normal diet for 8 weeks. Depression and anxiety were determined by open field test and elevated plus maze test. Immunohistochemistry for tryptophan hydroxylase (TPH) in the dorsal raphe, western blot analysis for phosphorylated protein kinase B (p-ATK), total AKT (t-AKT), phosphorylated phosphoinositide 3-kinase (p-PI3K), and total PI3K (t-PI3K) in the hippocampus were performed. Analysis of microbiome was also conducted. Obesity-induced depression and anx-iety status, suppressed ratio of p-AKT/t-AKT and p-PI3K/t-PI3K, and in-hibited TPH synthesis. Exercise and diet improved depression and anxi-ety status, activated p-AKT/t-AKT and p-PI3K/t-PI3K, and increased TPH synthesis. Exercise and diet improved depression and anxiety sta-tus by increasing the insulin signaling pathway and promoting serotonin production. These effects of exercise and diet were almost similar. In addition, exercise and diet regulated the composition of gut microbiota.

Peripheral nerve injuries are cause of sensory disturbances and in functional abilities, and are associated personal and social costs. Strat-egies that maximize nerve regeneration and functional recovery are necessary, the exercise is an option. This study evaluated the effects of forced swimming exercise on neuromuscular histomorphometry and on functional recovery in a median nerve crush model. Sixteen Wistar rats underwent median nerve crush and were divided into control group (CG) and swimming group (SG). The forced swimming protocol started one week after the injury and was performed for 1 hr a day, 5 days per week, for 2 weeks. The rats swam with an overload of 5% and 10% of body weight in the first and second week, respectively. The functional recovery was assessed in three moments using the grasping test. On day 21, fragments of the median nerve and of the forearm flexors mus-cles were removed for histomorphometric analysis. The SG had func-tional recovery impaired (P<0.001) and presented lower myelinated fi-bers number, fiber and axon minimal diameter, myelin thickness and g-ratio in the proximal e distal segments of the median nerve (P<0.005) and area muscle fiber (P<0.005) than CG. Also, the SG presented a number of capillaries in the proximal segments of the median nerve greater than CG (P<0.005). The exercise protocol used in this study im-paired the regeneration of the median nerve and negatively influenced the functional recovery.

A walking-based exercise program, called the cognitive walking pro-gram (CWP), has been shown to be beneficial for improving cognitive function in healthy older adults. It remains unknown whether it is bene-ficial for improving motor function of the brain. We investigated the ef-fects of CWP on motor function of the brain by examining changes in interlimb transfer of visuomotor adaptation in older adults. Subjects were divided based on their physical activity level (active vs. sedentary) and participated in CWP. A control group performed normal walking. Fifty-two healthy older adults, 67–78 years old, were studied. All sub-jects participated in CWP or normal walking for 6 months. To assess brain motor function, all subjects adapted to a rotated visual display during reaching movements with the right arm first, then with the left arm. Interlimb transfer of visuomotor adaptation was assessed at base-line, 3 months, and 6 months after training onset. It was hypothesized that if CWP had beneficial effects, the extent of transfer would change over time. The subject’s physical fitness was also assessed. Significant transfer from the right to the left arm occurred in all subject groups. Im-provements in physical fitness were also observed. However, the extent of transfer did not change even after 6 months, with no group differ-ence. Findings suggest that though beneficial for improving cognitive function in older adults, participating in CWP for 6 months is not long enough to improve brain motor function when the motor function is re-flected as changes in interlimb transfer of visuomotor adaptation.

The purpose of this study was to investigate the effects of sport game outcomes on acute affective responses in injured veterans. Twenty- three wheelchair basketball players (mean age, 38.39± 11.78 years) participated in this study and were divided into two groups: game winner group (n= 12) and game loser group (n= 11). All participants completed the Physical Activity Affect Scale immediately before and after participation in the first game of a wheelchair basketball tournament. Non-parametric statistical tests were used to examine a significant difference in acute affective responses between the groups and over time within each group. The losers experienced significantly higher negative affect and lower positive affect at the end of the first game compared to the winners. Therefore, the results of the present study indicated that the experience of losing may diminish the positive effect that sport participation can have.

The present study aimed to determine the isometric strength profile of the upper limb muscles of children and adolescents between 7–15 years of age. Furthermore, to (a) identify the age at which differences in strength are observed between sexes; to (b) determine the age range at which significant progression of strength could be observed; and (c) identify the role of each muscle on the total upper limb strength. Cross- sectional study that evaluated the isometric strength of nine muscle groups of the upper limb of 243 Chilean children, split into 9 age groups, separated by 1-year intervals. For this, hand-held dynamometry and hand-grip dynamometry were used. A two-factor analysis of variance for the maximum isometric strength and a stepwise multiple linear re-gression analysis were performed. From 11 years of age, wrist flexors were the first muscle group that revealed a significant difference in iso-metric strength in favor of boys (P=0.0143). In boys, the narrowest and earliest age range in the progression of isometric strength was 10 to 12 years for wrist flexors (P=0.0392). Shoulder flexors was the main factor that explained the performance of the total upper limb strength (R 2=0.742; P<0.001). The most progressive isometric strength develop-ment occurred from age 10 years in the ventral and distal muscles of the upper limb; and from this age the boys begin to present a greater isometric strength than girls. In addition, the isometric strength of shoul-der flexors explained the higher total upper limb strength performance.

This study was carried out to evaluate sensitivity, specificity, and test cutoff score to predict cardiorespiratory fitness by using the 2-min step test (2MST) in patients with type 2 diabetes mellites (DM). The associa-tion of the 2MST and physical fitness tests including a 6-min walk test (6MWT), a 5 time sit-to-stand test (FTSST), and leg strength in the form of a leg performance test were also investigated. This study was cross-sectional and conducted in 100 type 2 DM patients. Patients were screened through health questionnaires, medical illness, general char-acteristics, and physical fitness tests; 2MST, 6MWT, FTSST, and leg strength. Blood was collected for assessment of fasting blood sugar and lipid profiles. The number of steps in the 2MST was positively cor-related with the distance of the 6MWT (r=0.6995, P<0.0001) and leg strength (r=0.4292, P<0.0001). 2MST was negatively correlated with time to perform the FTSST (r=-0.405, P<0.0001). Moreover, this study established the optimal cutoff score of the 2MST at ≤61 steps with 92.24% sensitivity, and 81.36% specificity to predict cardiorespiratory fitness in type 2 DM patients. Our findings indicate that the 2MST may be used as a predictor for walking capacity, leg strength, and ability to change position from sitting to standing in type 2 DM. In addition, this result may imply that patients with type 2 DM performing the 2MST at less than 61 steps was significantly associated with decreased cardio-respiratory fitness.