Sports Medicine and Health Science最新文献

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.

The 800-m (m) run is part of Physical Education classes in Cameroon, after which arrhythmias may occur during recovery. Hence, this study aimed at determining relationship between 800-m run loads on cardiac autonomic recovery among school adolescents.

Forty-two male adolescents (aged [17 ​± ​1] years) performed 800-m. Post-exercise heart rate variability (HRV) was recorded during 5-min (min) (HRV_5-min) and 15-min (HRV_15-min) in time: Standard deviation of normal to normal (SDNN); Root mean square of successive differences (RMSSD) and frequency domain (LH: Low frequency, HF: High frequency, TP: Total power). Rating of Perceived Exertion (RPE) and blood lactate concentration (BLa) were measured after exercise. In HRV_5-min, RPE was associated with SDNN (r ​= ​−0.44, p ​< ​0.01) and RMSSD (r ​= ​−0.38, p ​< ​0.05). BLa was correlated with SDNN (r ​= ​−0.38, p ​< ​0.05) and RMSSD (r ​= ​−0.56, p ​< ​0.001) in the time-domain, LF (r ​= ​−0.64, p ​< ​0.001), HF (r ​= ​−0.58, p ​< ​0.001) and TP (r ​= ​−0.61, p ​< ​0.001) in frequency-domain. Moreover, RPE was correlated with LF (r ​= ​−0.44, p ​< ​0.01), TP (r ​= ​−0.49, p ​< ​0.01) while exercise duration with HF (r ​= ​−0.38, p ​< ​0.05). In HRV_15-min, BLa was correlated with RMSSD (r ​= ​−0.53, p ​< ​0.001) and SDNN (r ​= ​−0.68, p ​< ​0.001). RPE was negatively correlated SDNN (r ​= ​−0.53, p ​< ​0.01) and RMSSD (r ​= ​−0.44, p ​< ​0.01). BLa was associated with HF (r ​= ​−0.55, p ​< ​0.001), TP (r ​= ​−0.50, p ​< ​0.01) and RPE with LF (r ​= ​−0.51, p ​< ​0.01), HF (r ​= ​−0.50, p ​< ​0.01), TP (r ​= ​−0.49, p ​< ​0.01). In addition, exercise duration was negatively linked to HF (r ​= ​−0.36, p ​< ​0.05). This study outlined that in untrained adolescents an increase of 800-m loads is associated with a slow vagal indexes of HRV during the recovery.

Skeletal muscle size and strength are important for overall health for astronauts. However, how male and female muscle may respond differently to micro- and partial-gravity environments is not fully understood. The purpose of this study was to determine how biological sex and sex steroid hormones influence the progression of muscle atrophy after long term exposure to micro and partial gravity environments in male and female rats. Male and female Fisher rats (n ​= ​120) underwent either castration/ovariectomy or sham surgeries. After two weeks recovery, animals were divided into microgravity (0g), partial-gravity (40% of weight bearing, 0.4g), or full weight bearing (1g) interventions for 28 days. Measurements of muscle size and strength were evaluated prior to and after interventions. At 0g, females lost more dorsiflexion strength, plantar flexion strength, and other metrics of muscle size compared to males; castration/ovariectomy did not influence these differences. Additionally, at 0.4g, females lost more dorsiflexion strength, plantar flexion strength, and other metrics of muscle strength compared to males; castration/ovariectomy did not influence these differences. Females have greater musculoskeletal aberrations during exposure to both microgravity and partial-gravity environments; these differences are not dependent on the presence of sex steroid hormones. Correspondingly, additional interventions may be necessary to mitigate musculoskeletal loss in female astronauts to protect occupational and overall health.

Age-related sarcopenia places a tremendous burden on healthcare providers and patients' families. Blood flow restriction (BFR) training may be a promising treatment to bring sarcopenia down, and it offers numerous advantages over traditional resistance training. The purpose of this review was to compare the effects of BFR training and conventional resistance training on clinically delayed sarcopenia in the elderly. Databases such as PubMed, Web of Science, Embase, and Science Direct were searched to identify eligible studies; blinded data extraction was performed to assess study quality, and conflicts were submitted to third parties. Someone made the decision. One author used Review Manager (RevMan) 5.4 and compared it with data obtained by another author for this purpose. A total of 14 studies met the inclusion criteria for this review. The funnel plots of the studies did not show any substantial publication bias. Low-load blood flow restriction (LL-BFR) had no significant effect on muscle mass compared with high-load resistance training (HL-RT) (p ​= ​0.74, SMD ​= ​0.07, 95% CI: 0.33 to 0. 46) and LL-BFR had a significant effect on muscle strength compared with HL-RT (p ​= ​0.03, Z ​= ​2.16, SMD ​= ​-0.34, 95% CI: 0.65 to -0.03). LL-BFR showed a slight effect on mass compared to LL-RT (p ​= ​0.26, SMD ​= ​0.25, 95% CI: 0.19 to 0.69). Sensitivity analysis produced a nonsignificant change, suggesting that the results of this study are reasonable. In conclusion, the data suggest the possibility that BFR training improves age-related sarcopenia.

The purposes of this systematic review and meta-analysis of peer-reviewed literature were to examine the chronic effects of resistance training with blood flow restriction (RT-BFR) on hemodynamics, and to compare these adaptations to those induced by traditional resistance training (TRT) programs in adults (PROSPERO: Registry: CRD42022339510). A literature search was conducted across PubMed, Sports Discus, Scielo, and Web of Science databases. Two independent reviewers extracted study characteristics and blood pressure measures. Risk of bias (The Cochrane risk of bias tool for randomized controlled trials [RoB-2]), and the certainty of the evidence (Grading of Recommendations, Assessment, Development, and Evaluation [GRADE]) were used. A total of eight studies met the inclusion criteria for systolic (SBP), diastolic (DBP), and mean arterial pressure (MAP). Regarding the comparison of RT-BFR vs. non-exercise, no significant differences favoring the exercise group were observed (p ​> ​0.05). However, when compared to TRT, RT-BFR elicited additional improvements on DBP (−3.35; 95%CI -6.00 to −0.71; I² ​= ​14%; z ​= ​−2.48, p ​= ​0.01), and on MAP (−3.96; 95%CI -7.94 to 0.02; I² ​= ​43%; z ​= ​−1.95, p ​= ​0.05). Results indicate that RT-BFR may elicit a decrease in DBP in comparison with TRT, but the lack of data addressing this topic makes any conclusion speculative. Future research on this topic is warranted.

This study aimed to investigate the trends of finishers in the São Silvestre race in Brazil, taking into account sex, age, and performance levels. A total of 31 ​775 runners (women, n ​= ​13 ​847; men, n ​= ​17 ​928), aged (45.2 ​± ​16.8) years, finishers in the São Silvestre race between 2007 and 2021, were considered in the present analysis. Data (event year, date of birth, sex, and race times) were downloaded from the official race website. The man-Whitney U test, Spearman correlation, and robust regression model were computed. Participation increased over time for both sexes. Regarding age groups, “31–40 years” (women) and “> 60 years” (men) were those with the highest number of finishers. We found a decrease in performance across the years (β ​= ​2.45; p ​< ​0.005), as well as significant differences in race times for both sexes (U ​= ​42.844; p ​< ​0.001), with men presenting better performances than women. Over time, it was observed an increase in the performance gap between the sexes, but in general, the performance decreased (β ​= ​1.76; p ​< ​0.001). Stakeholders should consider improving the strategies to improve women and young people's participation in running events.

Deficits in the impulse control system are an important predictor of energy intake and body weight. Adults classified as overweight to obese may possess these deficits as a general behavioral trait or they may be food-specific. The present study assessed motor impulsivity (ability to suppress a pre-potent response) when presented with food and neutral (non-food) cues, testing if deficits in motor impulsivity is specific to food cues or a general trait among participants classified as overweight to obese. The proportion of inhibitory failures to no-go targets following food cues (10.8%) was significantly greater than the proportion of inhibitory failures to no-go targets following neutral cues (1.9%, p ​< ​0.001). These differences remained when covering for sex and hunger. This indicates deficits in food-specific impulse control (as opposed to general impulse control) are present in those classified as overweight to obese. Understanding the specific aspect of impulse control that is present in this population is needed for the development of future impulse control training interventions that seek to change eating behaviors as a means for weight control.