Questions remain about whether resistance exercise has a positive effect on immune and inflammatory cells. The purpose of this study was to evaluate the effect of 12 weeks of high-intensity circuit resistance exercise (HCRE) on inflammation and immune cells, and physical fitness, of female breast cancer survivors (FBCSs). Thirty FBCSs were randomly assigned to the HCRE (n = 15) and control (n = 15) groups. HRCE was administered for 50 min a day, 2–3 times a week, for 12 weeks. The control group only performed activities of daily living during the study period. Baseline and post-intervention measures included body composition, muscular strength, muscular endurance, flexibility, reaction time, balance, inflammation, and immune cell measurements. The results showed that HCRE improved body mass index, body fat, muscle mass, grip strength, back muscle strength, sit-up, whole-body reaction, standing on one leg with eyes closed, Y-balance test, and NKCA in FBCSs. The improvement of physical strength and immune cells of FBCSs was achieved using the 12-week HRCE program. Future studies must analyze various exercise intensities and types, and should be conducted on other cancer survivors. In addition, strategies should be developed to allow FBCSs to participate in resistance training.

This study aimed to investigate the effects of online physical education classes, using Tabata training, on middle school students’ physical fitness. Fifty-four adolescents were randomly assigned to either the asynchronous online class group (AOCG, n = 24, age: 15.8 ± 0.4 years) or the synchronous online class group (SOCG, n = 24 age: 15.9 ± 0.3 years). The online physical education class lasted two days per week for 10 weeks. Recorded video lectures were conducted for the AOCG, and Tabata training for the SOCG, as real-time lecture methods. Baseline and post-online physical education class measures included muscular strength, muscular endurance, flexibility, balance, and cardiorespiratory fitness tests. The results showed that the synchronous online physical education class had a positive effect on the improvement of muscle mass, ankle strength (dorsiflexion), hip strength (abduction, flexion, extension, and external rotation), knee strength (extension and flexion), and balance (Y-balance test) in adolescents. These findings suggest that the physical fitness of adolescents can be sufficiently improved through appropriate online physical education class methods. Further research should focus on developing and evaluating different types of exercises for synchronous online physical education classes as a precautionary measure for the second wave of COVID-19.

Reduced muscle mass and strength are notable features of aging. Loss of muscle mass contributes to cardiometabolic health. Although many studies have focused on skeletal muscle mass, it remains unclear whether muscle strength is beneficial for cardiometabolic health. We aimed to investigate the association between handgrip strength and the risk of adverse cardiometabolic health in middle-aged and older adults in the Korean general population. The study participants included 7602 adults from the Korea National Health and Nutritional Examination Survey (KNHANES). The odds ratio for adverse cardiometabolic health significantly and linearly decreased according to the category of handgrip strength adjusted for potential confounding factors (p-Value < 0.05). In the stratified models by sex we also observed significant associations between handgrip strength and cardiometabolic health in men (p-Value < 0.001), but not in women. Our findings suggest that maintaining higher handgrip strength may contribute to improved cardiometabolic health.

Background: At least 60 min of moderate-intensity physical activity per day is recommended for physical and mental health of adolescents. Schools are one of the most suitable places for promoting students’ health as it is a place where vigorous physical activity occurs. However, the physical activity of students is threatened because schools are closed worldwide owing to the coronavirus disease (COVID-19) outbreak in 2019. Therefore, this study aimed to analyze the physical fitness changes in 27,782 Korean adolescents during the pandemic and present alternative education and health policies to the school. Methods: We included 29,882 middle school students (age: 13–15 years; males: 14,941, females: 12,841) in Korea from 2019 to 2021 . Participants’ physical fitness at school was measured using the physical activity promotion system (PAPS) manual developed to measure students’ physical fitness. Physical fitness variables included body mass index (BMI), 20 m shuttle run, handgrip strength, sit-and-reach, and 50 m run. Results: The COVID-19 pandemic has had a negative impact on the BMI and cardiorespiratory endurance of Korean middle school students. Specifically, male students’ BMI increased, while body composition, cardiorespiratory endurance, and grip strength decreased significantly. Female students showed significant decreases in BMI and sit-and-reach test scores. It is clear that the physical fitness level of adolescents decreased by a greater degree after the COVID-19 pandemic than before, and the decrease in the physical fitness level of male students was noticeable. Therefore, a lesson strategy should be prepared that considers the contents and methods of physical education classes to improve the physical fitness level of male and female adolescents. Conclusions: Fitness-based classes suitable for online methods should be urgently added as alternative physical education classes to prepare for the second COVID-19 outbreak. In addition, it is necessary to create an environment in which physical activity is a possibility in physical education classes, in any situation using artificial intelligence and virtual reality.

Knowledge is limited regarding how neuromuscular training, conducted before and after soccer training, affects the fitness levels of youth soccer players. In this study, we aimed to analyze the effects of an eight-week neuromuscular training (NMT) program implemented before or after a soccer session on physical fitness in youth soccer players. Thirty-two youth soccer players were categorized into two groups—namely, NMT before soccer-specific training (NBS; n = 15) and NMT after soccer-specific training (NAS; n = 17). NMT comprised integrated resistance, dynamic stability, core, and plyometric training three times weekly and was conducted for 8 weeks. Before and after the exercise intervention, the counter-movement jump (CMJ) and 10 and 20 m sprint were analyzed, and the results of the T-agility test, Illinois change of direction test (ICDT), and Y-balance test were assessed for all participants. In terms of the interaction between the effects of the time of observation and group, both groups showed improvement in the results of the 10 m sprint and T-agility and Y-balance tests. Regarding the difference in the time of observation, the NBS group showed positive improvements in the results of the CMJ, 10 and 20 m sprints, and T-agility test after the exercise intervention, and the NAS group showed positive improvements in the results of the CMJ, 10 m sprint, T-agility test, and ICDT after the exercise intervention. These findings suggest that neuromuscular training has the potential to improve the 10 m sprint ability and T-agility test results of youth soccer players, regardless of the training sequence.

Backgrounds/Objectives: Adolescent soccer players are exposed to elevated injury risk due to rapid musculoskeletal development and high physical demands. Neuromuscular training (NMT) and speed–agility–quickness (SAQ) training are widely used to enhance performance and reduce injury risk in youth athletes. While both approaches are effective, comparative evidence regarding their modality-specific performance adaptations remains limited. Furthermore, few studies have discussed how such performance data may inform evidence-based or data-driven training selection in youth sports contexts. Methods: Thirty-six male youth soccer players with at least three years of playing experience, affiliated with Team A in Gyeonggi-do and Team B in Chungcheongbuk-do, participated in the study (NMTG, n = 21; SAQG, n = 15). Participants completed either an NMT or SAQ training program for eight weeks. To objectively assess exercise performance, pre- and post-tests were conducted measuring dynamic balance, vertical jump, zigzag run, and carioca. Results: Findings revealed a significant main effect of time for lower limb power (p < 0.05), but no significant group × time interaction, indicating that both NMTG and SAQG improved significantly over the 8-week period. Conversely, significant interaction effects were found for agility (p < 0.001), with SAQG demonstrating superior enhancements compared to NMTG. Dynamic balance showed no significant time effect or interaction. Conclusions: While NMTG and SAQG are equally effective for enhancing lower limb power, SAQG provides modality-specific advantages for agility in youth soccer players. These results emphasize time-dependent adaptations for power and the distinct benefits of SAQG for multi-directional speed. These adaptation profiles offer a data-driven framework for optimizing training selection in youth athletes.