The primary aim of this study was to examine the associations of normal weight obesity (NWO) with physical fitness in Chinese university students. As a secondary aim, we assessed whether possible differences in physical fitness between students classified as NWO and normal weight non-obese (NWNO) were mediated by skeletal muscles mass. A total of 383 students (205 males and 178 females, aged 18–24 years) from two universities volunteered to participate in this study. Body height and weight were measured by standard procedures and body composition was assessed by bio-impedance analysis (InBody 720). NWO was defined by a BMI of 18.5–23.9 kg/m2 and a body fat percentage of > 20% or > 30% in male and female students, respectively. Physical fitness was measured using a 10-min intermittent endurance running test (Andersen test), countermovement jumps (CMJ) and a 5 × 5 m shuttle run test (5mSR). The level of leisure time physical activity (PA) was assessed by a questionnaire. 13.7% of male and 27.5% of female students were classified as NWO. Compared to NWNO, students classified as NWO showed a significantly poorer performance in the Andersen test (males: 1146 ± 70 m vs. 1046 ± 95 m, females: 968 ± 61 m vs. 907 ± 67 m, p < 0.001), CMJ (males: 55.0 ± 7.6 cm vs. 44.9 ± 7.5 cm, females: 39.8 ± 8.0 cm vs. 33.7 ± 5.9 cm, p < 0.001) and 5mSR (males: 18.7 ± 1.0 s vs. 20.0 ± 0.9 s, females: 21.1 ± 1.1 s vs. 22.4 ± 1.3 s, p < 0.001), respectively. The lower levels of physical fitness in NWO were partially explained by lower skeletal muscle mass (p < 0.001) both in male and female students. NWO was associated with poorer physical fitness and the relationship was partially mediated by lower skeletal muscle mass. The study indicated that attention should be paid for the potential hidden health risk in university students with normal body mass index but excessive fat mass.

The purpose of this study was to characterize the inter-segmental coordination of hip, knee, and ankle movement of the kicking leg during instep kicking for experienced athletes and novices, using vector coding as a non-linear technique. Motion capture and electromyographic data were collected for 14 soccer-majored college students and 32 novices performing the instep kicking task. The percentage of time spent on the coordination patterns, defined based on hip–knee and knee–ankle coupling angles, was calculated and compared. The agonist–antagonist activity ratio was calculated and compared. The time percentages of the knee–ankle shank dominance of the experienced athletes during the whole kicking movement were significantly greater than those of the novices (p < 0.050). Athletes achieving greater maximum ball speed had more knee flexion dominant coordination patterns in the back swing and leg-cocking, and knee extension dominant coordination patterns in the leg acceleration phase. The lower activity ratio of the tibialis anterior and gastrocnemius muscles contributed significantly to increasing kicking accuracy. These results underscore the value of vector coding in identifying key inter-segmental coordination features and directly support targeted soccer kick training. The dynamic stability exercises involving knee flexion and extension to optimize power transfer for speed, as well as activation and relaxation control exercises of the lower leg muscles to improve the kicking accuracy, may be effective ways to enhance instep kicking motor control ability and performance for soccer athletes.

Background: Physical fatigue in soccer has been considered a risk factor for anterior cruciate ligament (ACL) injury, while mental fatigue could lead to decision-making errors and induce injuries. However, there is a lack of research on the combined effects of mental fatigue and decision making on lower limb biomechanics. Hypotheses: (1) Mental fatigue leads to a decrease in trunk flexion angle and knee flexion angle when touching the ground, as well as an increase in knee valgus moment and horizontal backward ground-reaction force (GRF) under unexpected conditions, which may lead to an increase in knee joint load. (2) The combined effects of mental fatigue and decision making lead to increased knee extension moment and valgus moment, leading to characteristics that may increase the risk of injury. Study Design: Descriptive laboratory study. Methods: Twenty male amateur soccer players were recruited as participants. Mental fatigue was induced through a 45-minute Stroop task, where the color of the screen changed randomly using a self-made infrared induction synchronous trigger to create different anticipated state scenes. A 12-lens infrared spot 3-dimensional (3D) motion capture system and 3D force plates were used to collect kinematic and dynamic data from the trunk and knee joints. Results: Mental fatigue and expected state demonstrated significant interaction effects on knee flexion angle and peak horizontal posterior GRF. At the initial contact, knee flexion angle ( P = .002) and trunk flexion angle ( P = .04) were significantly decreased post-mental fatigue compared with pre–mental fatigue. In the unanticipated condition, knee valgus moment was significantly increased ( P = .014). At the first peak of horizontal posterior GRF, compared with pre–mental fatigue, the trunk flexion angle ( P = .04) and knee flexion angle ( P = .017) were significantly decreased, and the peak horizontal posterior GRF ( P = .03) and knee valgus moment were significantly increased postfatigue ( P = .03). Conclusion: Soccer players demonstrated a more upright landing posture post–mental fatigue, and unanticipated conditions negatively affected trunk and knee movement patterns, potentially increasing the risk of ACL injury. The interaction of mental fatigue with unexpected factors did not appear to amplify the risk of ACL injury. Clinical Relevance: This study elucidates the effect of mental fatigue and decision making on the ACL. These risk factors may be incorporated into ACL prevention strategies.

Objectives: Physical activity plays a crucial role in promoting the health of the older adults. However, previous studies examined the influencing factors of physical activity among the older adults from a single-dimensional perspective, failing to adequately account for the interactions between various factors. Consequently, this study applied Andersen’s behavioral model to examine predisposing, enabling, and need factors associated with physical activity characteristics among the older adults. Methods: Based on Andersen’s behavioral model, this cross-sectional study analyzes factors affecting physical activity among 586 randomly older selected adults (aged ≥60) in Taiyuan via questionnaires. Factors are categorized into predisposing, enabling, and need dimensions, and are analyzed using ordinal and binary logistic regression. Results: Predisposing, enabling, and need factors were all associated with physical activity levels and insufficient physical activity among older adults. Specifically, gender (OR = 1.893, 95%CI: 1.303–2.751), age (OR = 1.739, 95%CI: 1.034–2.927), pension insurance purchase (OR = 0.312, 95%CI: 0.194–0.501), community facilities convenience score (OR = 1.363, 95%CI: 1.076–1.727), self-rated unhealthy health (OR = 0.375, 95%CI: 0.167–0.845), general health (OR = 0.372, 95%CI: 0.212–0.653), and relatively healthy (OR = 0.472, 95%CI: 0.281–0.793) were identified as significant predictors of physical activity levels. For insufficient physical activity, the influencing factors included gender (OR = 0.470, 95%CI: 0.302–0.732), age (OR = 0.458, 95%CI: 0.250–0.840), pension insurance purchase (OR = 3.944, 95%CI: 2.322–6.698), convenience of community facilities (OR = 0.718, 95%CI: 0.543–0.948), poor self-rated health (OR = 4.555, 95%CI: 1.811–11.456), and fair self-rated health (OR = 2.533, 95%CI: 1.302–4.926). Conclusion: Older adults’ physical activity levels needed improvement. Among these factors, age-related limitations can hinder participation in activities, while gender differences result in varying preferences and abilities regarding activities. Promoting pension insurance and improving community facilities could boost activity. Self-assessed health status is strongly associated with levels of physical activity. Governments should implement evidence-based health education, tailored incentives, strengthened community support networks, and upgraded age-friendly infrastructure to boost participation. These measures enhance public health and advance active aging through building age-friendly societies.

The purpose of this study was to determine the effects of coordination training and strength training on the lower extremity inter-segmental coordination during instep kicking for novices. Thirty-two male college students with no soccer-specific training experience participated and were randomly assigned to either a coordination training group, a strength training group, or a kicking training group. Each participant executed exercise training three times a week for eight weeks. The instep kicking test was performed before and after the three training sessions. Two-way ANOVAs were conducted to determine the training effects on the kicking performance and the inter-segmental coordination. The maximum ball speed significantly increased after the three trainings, but the kicking accuracy significantly increased only after coordination training. The time spent percentage of knee-ankle shank-phase coordination pattern in the leg-cocking phase were significantly increased, but the time spent percentage of hip-knee thigh-phase in the back swing phase significantly decreased after the three trainings. The co-activation of the tibialis anterior and gastrocnemius muscles significantly decreased only after coordination training. The lower extremity inter-segmental coordination during instep kicking was significantly improved after training.Coordination training may improve the neuromuscular motor control functions during the instep kicking more effectively.

The purpose of this study was to determine the effects of coordination training and strength training on the lower extremity inter-segmental coordination during instep kicking for novices. Thirty-two male college students with no soccer-specific training experience participated and were randomly assigned to either a coordination training group, a strength training group, or a kicking training group. Both the coordination and strength training groups also performed the same kicking training as the kicking training group. Each participant executed exercise training three times a week for eight weeks. The instep kicking test was performed before and after the three training sessions. Two-way ANOVAs were conducted to determine the training effects on the kicking performance and the inter-segmental coordination. The maximum ball speed significantly increased for all three training groups (p < 0.001, effect size = 0.638). In contrast, improvements in kicking accuracy were specific to the coordination training group (p = 0.001, effect size = 0.326), with no significant changes observed in the strength (p = 0.052, effect size = 0.138) or kicking groups (p = 0.953, effect size < 0.001). The time spent percentage of the knee-ankle shank-phase coordination pattern in the leg-cocking phase was significantly increased (p = 0.003, effect size = 0.268), but the time spent percentage of the hip-knee thigh-phase in the back swing phase significantly decreased after the three trainings (p = 0.031, effect size = 0.150). A significant reduction in the relative activity of the tibialis anterior and gastrocnemius muscles occurred exclusively after coordination training (p = 0.024, effect size = 0.188). This study confirms that coordination training provides a unique contribution to skill acquisition in novices, specifically enhancing kicking accuracy and neuromuscular control, whereas improvements in maximal ball speed were generic to all training types.