Sports Medicine and Health Science最新文献

There is a recent and growing interest in assessing differential responders to resistance training (RT) for diverse outcomes. Thus, the individual ability to respond to an intervention for a specific measurement, called responsiveness, remains to be better understood. Thus, the current study aimed to summarize the available information about the effects of RT on functional performance and muscle strength, power, and size in healthy adults, through the prevalence rate in different responsiveness classifications models. A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and was registered at the International Prospective Register of Systematic Reviews (PROSPERO, CRD42021265378). PubMed/MEDLINE, Scopus, and Embase databases were systematically searched in October 2023. A total of 13 studies were included, totaling 921 subjects. Only two studies presented a low risk of bias. Regarding the effectiveness of RT, the prevalence rate for non-responders ranged from 0% to 44% for muscle strength, from 0% to 84% for muscle size, and from 0% to 42% for functional performance, while for muscle power, the only study found showed a responsiveness rate of 37%. In conclusion, a wide range of differential responders is described for all variables investigated. However, the evidence summarized in this systematic review suggested some caution while interpreting the findings, since the body of evidence found seems to be incipient, and widely heterogeneous in methodological and statistical aspects.

The study aims to investigate the differences in protein expressions in Xizang's (Tibetan) middle-to-long distance runners after the transition from high altitude to low altitude and reveal the molecular mechanisms underlying their enhanced middle-to-long distance running performance. In the study, eleven subjects were selected from native Tibetan middle-to-long distance runners to participate in an 8-week pre-competition exercise training program consisting of a 6-week training stage in Kangding City at an altitude of 2 560 meters (m) and a subsequent 2-week training stage in Leshan City at an altitude of 360 ​m. Blood samples were collected twice from the runners before beginning altitude exercise training in Kangding and after going to sea level - Leshan City. Using a label-free quantitative method, peptides in the samples were analyzed by mass spectrometry. Proteomic analysis was performed to identify differentially expressed proteins and predict their biological functions. A total of 846 proteins were identified in the 21 samples, including 719 quantified proteins. In total, 49 significantly differentially expressed proteins (p ​< ​0.05) were identified, including twenty-eight 0.2-fold up-regulated proteins or twenty-one 0.17-fold down-regulated proteins. The up-regulated proteins, including cystic fibrosis transmembrane conductance regulator (CFTR) and carbonic anhydrase I (CAI), were of particular interest due to their role in regulating the oxygen saturation in deep tissues. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis indicated that these proteins were mainly involved in regulating actin cytoskeleton, local adhesion, biotin absorption and metabolism, immune system, cancer, and membrane transport processes. In conclusion, Tibetan middle-to-long distance runners who resided in high-altitude areas benefited from repeated plateau-plain alternate training mode during the pre-competition period. The training mode induced positive changes in peripheral blood plasma proteins (CFTR and CAI), the biomarkers associated with aerobic capacity. Among the 11 runners, one female athlete won the gold medal in the 3 000-m running event in this competition, demonstrating that the plateau-plain alternate training mode could enhance the aerobic capacity of athletes.

Electrocardiographic characteristics of children and adolescents present differences compared to adults. The aim of our work was to study electrocardiograms (ECGs) of football male players from childhood to late adolescence and examine if the ECG parameters are influenced by systematic exercise. One thousand fifty-four football players participated and formed four groups. Group A included 89 players aged 5–7 years, group B 353 players aged 8–11 years, group C consisted of 355 football players 12-15 yearsold and group D of 257 players with 16–18 years of age. All participants underwent preparticipation screening, including 12-lead surface ECG. Heart rate (HR), PR, RR, QRS, QT, QTc intervals, QT dispersion (QTdisp) and QRS axis were calculated. All ECGs were evaluated according to the current preparticipation cardiac screening guidelines, that refer to athletes aged 12–35 years and do not include pediatric players. Eleven percent of the participants presented an ECG finding. Group D obtained the lowest values of HR, QTc and the highest of PR, RR, QRS, QT intervals and QTdisp, whereas no differences in QRS axis were reported. Incomplete Right Bandle Branch Block (RBBB) was the most frequent ECG peculiarity, detected in 7.3% of the participants. Years of training were statistically significantly correlated to HR, PR, RR, QRS and QT intervals. In conclusion, guidelines for ECG interpretation of athletes in childhood, early and late adolescence are needed.

Obesity has a complex multifactorial etiology and is characterized by excessive accumulation of adipose tissue. Visceral adipose tissue has deleterious effects on health because it secretes large amounts of inflammatory cytokines. Nutritional calorie restriction associated with strength training may be useful in managing chronic systemic inflammation. This study aimed to evaluate the acute effect of a single strength-training session on plasma adipokine levels in sedentary, overweight, and obese young men. This study included twelve men (Age: [34.95 ​± ​9.77] years; Height: [174.16 ​± ​3.66] centimeter [cm]; Weight: [97.83 ​± ​12.87] kilogram (kg); body mass index [BMI]: [32.30 ​± ​4.51] kg/m²), who performed a single strength training session. The strength training protocol consisted of 4 sets of 12 repetitions in the following six exercises, 45° leg press, bench press, leg extension, machine row, leg curl, and shoulder press. Blood samples were collected before, immediately after, and 1-h subsequent after strength training. The plasma levels of resistin and leptin were measured. A significant decrease in resistin levels were found 1 ​h after the strength training session if compared to levels before the training session (pre-[before] [2 390 ​± ​1 199] picograms per milliliter [pg/mL] vs post-1 h [1-h subsequent] [1 523 ​± ​798],6 ​pg/mL, p ​= ​0.002 8). The plasma leptin levels did not differ at any time point. In conclusion, a very well controlled single session of strength training significantly decreased the plasma levels of resistin without altering the concentration of leptin in overweight and obese individuals. This effect, at least in part, supports the benefits of exercise by reducing the low grade inflammation and insulin resistance in obesity.

This cross-sectional study examined the lower limb balance, ankle dorsiflexion, orofacial tissue pressure, and occlusal strength of rugby players. Twenty-six participants were divided into groups: rugby players (n ​= ​13) and healthy sedentary adults (n ​= ​13). Participants underwent an analysis of lower limb balance using a composite score (Y-Balance Test). Ankle dorsiflexion was measured using the Lunge Test. The Iowa Oral Performance Instrument was employed to measure orofacial tissue pressure. Bite force was measured with a dynamometer, and T-Scan assessed occlusal contact distribution. Data were analyzed using the t-test (p ​< ​0.05) and ANCOVA with age and weight as covariates, where it is possible to verify that these factors did not influence the results obtained. Significant differences were observed in the balance of the right (p ​= ​0.07) and left (p ​= ​0.02) lower limbs, where rugby players had lower composite scores. There were significant differences in the right (p ​= ​0.005) and left (p ​= ​0.004) lunges, with rugby players showing lower values, as well as lower tongue pressure (p ​= ​0.01) and higher lip pressure (p ​= ​0.03), with significant differences to sedentary participants. There was no significant difference in molar bite force and distribution occlusal contacts between groups. Rugby seems to reduce lower limb displacement, cause ankle hypomobility, lead to changes in orofacial tissues, particularly the tongue and lips. This study is significant for identifying significant differences between rugby players and sedentary individuals, providing new insights into the impact of rugby on health and performance, which can benefit sports training and injury prevention.

Fractures are costly to treat and can significantly increase morbidity. Although dual-energy x-ray absorptiometry (DEXA) is used to screen at risk people with low bone mineral density (BMD), not all areas have access to one. We sought to create a readily accessible, inexpensive, high-throughput prediction tool for BMD that may identify people at risk of fracture for further evaluation. Anthropometric and demographic data were collected from 492 volunteers (♂275, ♀217; [44 ​± ​20] years; Body Mass Index (BMI) = [27.6 ​± ​6.0] kg/m²) in addition to total body bone mineral content (BMC, kg) and BMD measurements of the spine, pelvis, arms, legs and total body. Multiple-linear-regression with step-wise removal was used to develop a two-step prediction model for BMC followed by BMC. Model selection was determined by the highest adjusted R², lowest error of estimate, and lowest level of variance inflation (α ​= ​0.05). Height (HTcm), age (years), sex^{m=1, f=0}, %body fat (%fat), fat free mass (FFMkg), fat mass (FMkg), leg length (LLcm), shoulder width (SHWDTHcm), trunk length (TRNKLcm), and pelvis width (PWDTHcm) were observed to be significant predictors in the following two-step model (p ​< ​0.05). Step1: BMC (kg) = (0.006 3 $\times$ HT) ​+ ​(−0.002 4 $\times$ AGE) ​+ ​(0.171 2 $\times$ SEX^{m=1, f=0}) ​+ ​(0.031 4 $\times$ FFM) ​+ ​(0.001 $\times$ FM) ​+ ​(0.008 9 $\times$ SHWDTH) ​+ ​(−0.014 5 $\times$ TRNKL) ​+ ​(−0.027 8 $\times$ PWDTH) - 0.507 3; R² ​= ​0.819, SE ​± ​0.301. Step2: Total body BMD (g/cm²) = (−0.002 8 $\times$ HT) ​+ ​(−0.043 7 $\times$ SEX^{m=1, f=0}) ​+ ​(0.000 8 $\times$ %FAT) ​+ ​(0.297 0 $\times$ BMC) ​+ ​(−0.002 3 $\times$ LL) ​+ ​(0.002 3 $\times$ SHWDTH) ​+ ​(−0.002 5 $\times$ TRNKL) ​+ ​(−0.011 3 $\times$ PWDTH) ​+ ​1.379; R² ​= ​0.89, SE ​± ​0.054. Similar models were also developed to predict leg, arm, spine, and pelvis BMD (R² ​= ​0.796–0.864, p ​< ​0.05). The equations developed here represent promising tools for identifying individuals with low BMD at risk of fracture who would benefit from further evaluation, especially in the resource or time restricted setting.

Behavioral experiments have demonstrated that long-term physical exercise can be beneficial for learning and memory dysfunction caused by neuroinflammation in Alzheimer's disease (AD). However, the molecular mechanism remains poorly understood due to a lack of sufficient pertinent biochemical evidence. We investigated the potential effect of long-term physical exercise on cognition and hippocampal gene and protein expression changes in a transgenic AD mouse model. Following twenty weeks of treadmill exercise, transgenic AD mice showed improvement in cognitive functions and downregulation of Nod-like receptor protein 3 (NLRP3) (p ​< ​0.01), interleukin-1beta (IL-1β) (p ​< ​0.05), and amyloid-β_1-42 (Aβ_1-42) (p ​< ​0.05) expression levels. In addition, we observed significant reductions of microglial activation and hippocampal neuronal damage in the exercised AD mice (p ​< ​0.01), which might be a result of the downregulation of NLRP3-mediated signaling and neuro-inflammatory responses. As neuronal damage due to inflammation might be a likely cause of AD-associated cognitive dysfunction. Our results suggested that the anti-inflammatory effects of exercise training involved downregulating the expression of key inflammatory factors and might play an important role in protecting hippocampal neurons against damage during the course of AD.

Success in speed swimming depends on the efficiency of the anaerobic system for the production of cellular energy, especially during muscle power production. In the adolescent athletes much is unknown with regards to the relationships between relative power of upper and lower limbs with speed swimming performance. The aim the present study was to identify differences in relative muscle power of upper and lower limbs in adolescent swimmers and relate these to speed swimming performances. Sixty adolescents, of both sexes (50% female, 50% male, 30 swimmers and 30 controls), were recruited. The relative upper limb power (ULP_[W/kg]) was assessed by a medicine ball test and the relative lower limbs power (LLP_[W/kg]) by a jump test on a jumping platform. Lean mass of the upper and lower limbs was assessed by dual-energy X-ray absorptiometry (DXA) (g). Sport performance was assessed during national level competition (50-m swimming time [in seconds]). Biological maturation (BM) was indexed by years from attainment of peak height velocity. ULP_(W/kg) was higher than LLP_(W/kg) in both groups (p ​< ​0.05). Upper and lower limb lean mass (g) correlated significantly with ULP_(W/kg) and LLP_(W/kg) in both groups (p ​< ​0.05). ULP_(W/kg) and LLP_(W/kg) correlated with 50-m swimming performance (s), in both sexes (p ​< ​0.05). Advanced BM was associated with ULP_(W/kg) and LLP_(W/kg) in both groups (p ​< ​0.05), and with 50-m swimming performance (s) in both sexes (p ​< ​0.05). We concluded that ULP_(W/kg) is higher than LLP _(W/kg) in adolescent swimmers. Upper and lower limb lean mass and BM were both positively associated with increased ULP _(W/kg) and LLP _(W/kg).

The purpose of this review and commentary was to provide an historical and evidence-based account of organic acids and the biochemical and organic chemistry evidence for why cells do not produce metabolites that are acids. The scientific study of acids has a long history dating to the 16^th and 17^th centuries, and the definition of an acid was proposed in 1884 as a molecule that when in an aqueous solution releases a hydrogen ion (H⁺). There are three common ionizable functional groups for molecules classified as acids: 1) the carboxyl group, 2) the phosphoryl group and 3) the amine group. The propensity by which a cation will associate or dissociate with a negatively charged atom is quantified by the equilibrium constant (K_eq) of the dissociation constant (K_d) of the ionization (K_eq ​= ​K_d), which for lactic acid (HLa) vs. lactate (La^-) is expressed as: $K_{eq}=K_d=\frac{\left[H^{+}\right]\left[{La}^{-}\right]}{\left[HLa\right]}=$ 4 677.351 4 (ionic strength ​= ​0.01 Mol⋅L^-1, T ​= ​25 ​°C). The negative log₁₀ of the dissociation pK_d reveals the pH at which half of the molecules are ionized, which for HLa ​= ​3.67. Thus, knowing the pK_d and the pH of the solution at question will reveal the extent of the ionization vs. acidification of molecules that are classified as acids.

Exercise has well-characterized therapeutic benefits in the management of type 2 diabetes mellitus (T2DM). Most of the beneficial effects of exercise arise from the impact of nuclear factor erythroid 2 related factor-2 (Nrf2) activation of glucose metabolism. Nrf2 is an essential controller of cellular anti-oxidative capacity and circadian rhythms. The circadian rhythm of Nrf2 is influenced by circadian genes on its expression, where the timing of exercise effects the activation of Nrf2 and the rhythmicity of Nrf2 and signaling, such that the timing of exercise has differential physiological effects. Exercise in the evening has beneficial effects on diabetes management, such as lowering of blood glucose and weight. The mechanisms responsible for these effects have not yet been associated with the influence of exercise on the circadian rhythm of Nrf2 activity. A better understanding of exercise-induced Nrf2 activation on Nrf2 rhythm and signaling can improve our appreciation of the distinct effects of morning and evening exercise. This review hypothesizes that activation of Nrf2 by exercise in the morning, when Nrf2 level is already at high levels, leads to hyperactivation and decrease in Nrf2 signaling, while activation of Nrf2 in the evening, when Nrf2 levels are at nadir levels, improves Nrf2 signaling and lowers blood glucose levels and increases fatty acid oxidation. Exploring the effects of Nrf2 activators on rhythmic signaling could also provide valuable insights into the optimal timing of their application, while also holding promise for timed treatment of type 2 diabetes.