Resistance exercise (RE) is a potent hypertrophic stimulus for skeletal muscle but simultaneously imposes mechanical strain that induces focal microdamage within the sarcomeric force-transmission network. This review synthesizes evidence describing how early, damage-driven cytoskeletal repair responses establish the structural basis for effective hypertrophic remodeling in repeatedly RE-stimulated human skeletal muscle. We integrate literature at the intersection of muscle damage, proteostatic regulation, and human adaptation to RE, highlighting molecular damage control as a central yet underappreciated component of resistance training adaptation. Particular emphasis is placed on chaperone-assisted selective autophagy (CASA) and the small heat shock protein αB-crystallin (CRYAB), key regulators of proteostasis in mechanically stressed muscle. We outline mechanisms governing muscle anabolism and catabolism, the structural localization of RE-induced microdamage, and acute mechanoprotective programs involving CASA and small heat shock proteins. We propose that microlesions function as focal signaling hubs linking mechanical strain to transcriptional control via a CRYAB–SMAD4 axis. Following intense or unfamiliar RE, rapid CRYAB phosphorylation stabilizes strained cytoskeletal proteins and supports BAG3-dependent turnover, while spatial mTORC1 modulation enables localized autophagy alongside preserved protein synthesis. With repeated training, cytoskeletal reinforcement reduces lesion burden and shifts remodeling toward net myofibrillar accretion, informing mechanistically grounded RE program design.

PURPOSE: To perform a meta-analysis of the effects of plyometric training on the physical performance of male basketball players.METHODS: The Google Scholar, PubMed and ScienceDirect databases were searched for relevant studies published between 2016 and 2024. Subsequently, a meta-analysis was performed on variables extracted from 19 studies that corresponded to the study design.RESULTS: The effect of plyometric training on the physical fitness of male basketball players, divided into 2 groups (≥7 and <7 weeks), revealed that countermovement jump (0.55), vertical jump (1.05) and T–change of direction test (-1.30) had greater effects after 7 weeks, whereas Illinois agility test (-1.39), 20 m sprint test (-0.85) demonstrated greater effects in <6 weeks.CONCLUSIONS: The results of this study suggest that plyometric training can effectively enhance game-related physical abilities in adult male basketball players. Furthermore, the findings indicate that the effects are particularly pronounced when the training duration is considered during the design of a plyometric training program.

PURPOSE: Type 2 diabetes is rapidly increasing in prevalence worldwide and, along with metabolic syndrome, serves as a major precursor to cardiovascular and cerebrovascular diseases. Physical inactivity is recognized as a significant contributing factor to both conditions. Therefore, an empirical review of the effectiveness of exercise interventions is essential. This study aimed to analyze the impact of aerobic physical activity and regular strength training on the prevalence of type 2 diabetes and metabolic syndrome risk factors, with the goal of providing evidence to guide the development of targeted exercise prescriptions and lifestyle improvement strategies tailored to the Korean adult population.METHODS: Using raw data from the 2023 Korea National Health and Nutrition Examination Survey (KNHANES), we analyzed responses from 4,881 adults aged 19 years and older. Participants were categorized into four groups according to their engagement in aerobic physical activity and strength training. Key metabolic syndrome markers such as blood pressure, fasting glucose, triglycerides, and high-density lipoprotein cholesterol (HDL-C), along with the prevalence of type 2 diabetes, were examined. Statistical analyses included descriptive statistics, analysis of covariance (ANCOVA), and multivariate logistic regression. All analyses were adjusted for potential confounding variables, including age, sex, body mass index (BMI), smoking status, and alcohol consumption.RESULTS: After adjusting for confounding factors, individuals who participated in both aerobic physical activity and regular strength training had a 56% lower risk of type 2 diabetes compared to those who participated in neither activity (odds ratio [OR]: 0.44, 95% confidence interval [CI]: 0.28–0.70).CONCLUSIONS: Combining aerobic activity with strength training is more effective than either modality alone in reducing diabetes prevalence and improving metabolic syndrome risk factors. These findings underscore the need to develop integrated exercise guidelines and practical lifestyle modification programs, rather than broad public health policies, to optimize metabolic health and provide actionable recommendations for clinical and community settings.

PURPOSE: Sand walking, a type of marine healing program, has been adopted as a sports training and rehabilitation method because it lowers the risk for injury by reducing muscle and joint loads through shock relief. This study performed a three-dimensional (3D) biomechanical analysis to compare walking on firm versus sandy surfaces in healthy adults in a laboratory environment that closely replicated real beach sand.METHODS: The 3D joint range of motion (ROM), stance time and muscle activity of the lower extremities were analyzed while 34 healthy adults walked on firm versus sandy surfaces using a constructed sand track (7.2×0.9×0.2 cm).RESULTS: Sagittal ROMs of the hip and knee joints were significantly greater on the sandy surface than those on the firm surface, whereas the horizontal ROM of the knee joint was significantly lower on the sandy surface than that on the firm surface. Ankle ROMs were significantly greater across all planes. Significantly longer stance times were observed for the sandy surface versus the firm surface. The gastrocnemius and gluteus medius muscles exhibited significantly higher activity on the sandy surface versus the firm surface during the loading and terminal stance phases.CONCLUSIONS: This study revealed 3D biomechanical changes in the lower extremities during sand walking, increasing joint ROM and muscle activity while extending stance time, suggesting that beach sand is a suitable resource for gait rehabilitation and marine healing programs.

PURPOSE: This study aimed to examine the differences in telomere length according to sport type, physical activity level, body composition, and cardiorespiratory fitness among young adult male athletes and physical education majors, and to identify physiological factors that influence telomere length.METHODS: A total of 105 participants, including collegiate athletes and physically active students in their 20s, were recruited. Telomere length was measured using quantitative PCR. Physical activity levels were assessed using the International Physical Activity Questionnaire (IPAQ) and expressed as weekly energy expenditure (kcal/week). Body composition and cardiorespiratory fitness were evaluated using a multi-frequency bioelectrical impedance analyzer (InBody 770) and VO<sub>2</sub>max test via the Bruce protocol. Data were analyzed using one-way ANOVA, Games-Howell post hoc test, Pearson correlation, and linear regression analysis.RESULTS: Significant differences were found among sport types in height, muscle mass, and telomere length. Differences in moderate-and low-intensity physical activity were also observed between groups. Telomere length showed a significant positive correlation with muscle mass (r=0.470, <i>p</i><.001) and cardiorespiratory fitness (r=0.217, <i>p</i>=.008), and both variables were identified as significant predictors in the regression model. However, no statistically significant differences in telomere length were found across physical activity quartiles.CONCLUSIONS: This study suggests that muscle mass and cardiorespiratory fitness are key physiological factors associated with telomere length in young adults. While an adequate level of physical activity may contribute to telomere maintenance, excessive exercise may have adverse effects. Further research is needed to explore telomere length as a potential biomarker for health monitoring in athletic populations.

PURPOSE: This study aimed to analyze the associations among insulin resistance (IR), type 2 diabetes mellitus (T2DM), physical activity, and knee osteoarthritis (KOA) in older women.METHODS: A total of 2,217 women aged ≥65 years who participated in the Korea National Health and Nutrition Examination Survey (2009–2013) were included. IR was assessed using the triglyceride-glucose body mass index, and participants were classified as normal or abnormal based on cutoffs. T2DM was defined as having a fasting glucose level >126 mg/dL, a physician-diagnosed diabetes history, or current treatment for diabetes. Physical activity was assessed using the International Physical Activity Questionnaire and categorized by whether participants engaged in ≥150 min/week of light-intensity physical activity (LPA) or moderate-to-vigorous physical activity (MVPA). KOA was defined as Kellgren-Lawrence (KL) grade ≥2, and categorized as follows: KL 0–1=normal, KL 2=light KOA, KL 3–4=moderate-to-severe KOA.RESULTS: Logistic regression showed significantly higher KOA risk in the abnormal IR group (OR=1.768, 95% CI=1.486–2.105) and T2DM group (OR=1.311, 95% CI=1.054–1.631) compared to the normal group. Participants with <150 min/week of LPA had higher KOA risk (OR=1.378, 95% CI=1.158–1.639) than those with ≥150 min/week. In the IR and T2DM groups, participants engaging in <150 min/week of LPA had significantly higher odds of moderate-to-severe KOA compared to those with ≥150 min/week.CONCLUSIONS: Engaging in >150 min/week of LPA may be a practical and effective strategy for the prevention of KOA in older women with impaired glucose metabolism.

PURPOSE: To analyze the correlation between leg length (femur, tibia, and total leg length) and key physical fitness components (muscular strength, muscular endurance, power, agility, flexibility, cardiorespiratory endurance, and anaerobic power) in elite male and female athletes across various sports disciplines.METHODS: Data from 273 athletes (168 male, 105 female), who underwent anthropometric and physical fitness assessments, were analyzed. Both absolute and relative leg lengths (standardized to height) were examined.RESULTS: Longer tibial length combined with shorter femoral length was associated with greater agility in male athletes. In contrast, female athletes with longer total leg length exhibited higher anaerobic power. Female athletes with shorter tibial length and longer femoral length exhibited better muscular endurance. Power was positively correlated with leg length among male athletes. However, there was no significant correlation between leg length and cardiorespiratory endurance in either sex.CONCLUSIONS: Findings suggested that advantageous segmental proportions in the lower limbs may vary according to sex and may be associated with specific components of physical performance. These results may serve to inform the development of preliminary guidelines for athlete selection, evaluation of sports-specific suitability, training programs, and injury prevention strategies.

PURPOSE: Metabolic syndrome (MS) is a major precursor to type 2 diabetes and cardiovascular disease. Conventional glycemic markers such as fasting glucose and HbA1c do not capture dynamic glucose fluctuations. This review examines the metabolic risks associated with glycemic variability (GV) in adults with MS and explores the potential of breaking up prolonged sitting and the soleus push-up (SPU).METHODS: A narrative review was conducted using Web of Science, PubMed, and Google Scholar for literature published from January 2000 and August 2025. Search terms included “glycemic variability,” “metabolic syndrome,” “breaking up prolonged sitting,” “continuous glucose monitoring (CGM),” and “SPU.” Evidence regarding GV was limited to studies involving MS, while studies in broader populations included to contextualize mechanisms of sedentary interruption strategies.RESULTS: GV is independently linked to oxidative stress, endothelial dysfunction, and inflammation, contributing to elevated diabetes and cardiovascular risks in MS. CGM studies generally report higher GV indices in MS than in metabolically healthy adults, although findings for coefficient of variation and mean amplitude of glucose excursions are inconsistent. Prolonged sedentary behavior worsens postprandial glycemia, whereas interrupting sitting with light walking or standing consistently improves postprandial glucose and, in some trials, lowers mean glucose or iAUC without uniform changes in GV metrics. Emerging evidence suggests that SPU, utilizing the high oxidative capacity of the soleus muscle, reduces postprandial glucose and hyperinsulinemia with minimal fatigue, with additional potential benefits for lipid metabolism.CONCLUSIONS: Breaking up prolonged sitting is a practical strategy to attenuate postprandial dysglycemia, and SPU represents a promising sedentary-interruption modality. However, evidence on its direct effects on GV in MS is limited, underscoring the need for large-scale randomized trials.

PURPOSE: To investigate the combined effects of proprioceptive neuromuscular facilitation (PNF) and joint mobilization on shoulder function, acromiohumeral distance (AHD), pressure pain threshold (PPT), and muscle activity in patients with subacromial impingement syndrome.METHODS: Thirty patients with subacromial impingement syndrome were randomly assigned to an experimental group (conventional rehabilitation plus PNF and joint mobilization, n=15) or a control group (conventional rehabilitation plus joint mobilization, n=15). Interventions were administered 5 times per week for 4 weeks. Outcome measures included the Shoulder Pain and Disability Index (SPADI), AHD, PPT, and surface electromyographic activity of the upper and lower trapezius and serratus anterior muscles.RESULTS: Both groups exhibited significant within-group improvements in SPADI, PPT, and muscle activity (<i>p</i><.05), whereas AHD increased significantly only in the experimental group. Between-group comparisons revealed greater improvements in SPADI, AHD, and PPT in the experimental group (<i>p</i><.05). The experimental group exhibited decreased upper trapezius activation and increased lower trapezius activation compared with the control group (<i>p</i><.05), while serratus anterior activity increased similarly in both groups. Two-way repeated measures analysis of variance revealed significant group×time interactions for AHD, PPT, and muscle activity (<i>p</i><.05, <i>η</i><sup>2</sup>=0.13–0.50), indicating superior structural and neuromuscular adaptations in the experimental group.CONCLUSIONS: The combined PNF and joint mobilization intervention yielded greater improvements in shoulder function, structure, and neuromuscular adaptation, supporting its clinical utility for patients diagnosed with subacromial impingement syndrome.