Background: Aerobic exercise is known to reduce arterial stiffness; however, high-intensity resistance exercise is associated with increased arterial stiffness. Stretching exercises are another exercise modality, and their effect on arterial stiffness remains unclear. The purpose of this study was to determine whether stretching exercises reduce arterial stiffness in middle-aged and older adults, performing the first meta-analysis of currently available studies. Methods: We searched the literature for randomized controlled trials (RCTs) and non-RCTs published up to January 2020 describing middle-aged and older adults who participated in a stretching intervention vs. controls without exercise training. The primary and secondary outcomes were changes in arterial stiffness and vascular endothelial function and hemodynamic status. Pooled mean differences (MDs) and standard MDs (SMDs) with 95% confidence intervals (CIs) between the intervention and control groups were calculated using a random effects model. Results: We identified 69 trials and, after an assessment of relevance, eight trials, including a combined total of 213 subjects, were analyzed. Muscle stretching exercises were shown to significantly reduce arterial stiffness and improve vascular endothelial function (SMD: −1.00, 95% CI: −1.57 to −0.44, p = 0.0004; SMD: 1.15, 95% CI: 0.26 to 2.03, p = 0.01, respectively). Resting heart rate (HR) and diastolic blood pressure (DBP) decreased significantly after stretching exercise intervention (MD: −0.95 beats/min, 95% CI: −1.67 to −0.23 beats/min, p = 0.009; MD: −2.72 mm Hg, 95% CI: −4.01 to −1.43 mm Hg, p < 0.0001, respectively) Conclusions: Our analyses suggest that stretching exercises reduce arterial stiffness, HR, and DBP, and improve vascular endothelial function in middle-aged and older adults.

Background/Objectives: Low masticatory function has been proposed as a risk factor for sarcopenia. This study investigated its potential association with body composition and physical performance in community-dwelling older adults. Methods: Participants included adults aged ≥65 years (643 men; 797 women) who volunteered for a longitudinal cohort study. Masticatory function was objectively assessed using gummy jelly and subjectively evaluated via a structured questionnaire. The skeletal muscle mass, body mass index, waist circumference, handgrip strength, gait speed, and five-time chair-stand test were assessed. Results: Objectively measured masticatory function was classified as low (12.6%), moderate (38.0%), or high (49.4%). In men, masticatory function was significantly associated with skeletal muscle mass index (low, moderate, and high: 7.4, 7.7, and 7.7 kg/m²; p = 0.005), handgrip strength (31.8, 34.2, and 35.5 kg; p < 0.001), and gait speed (1.3, 1.4, and 1.4 m/s; p = 0.003). In women, low masticatory function was linked to a higher body mass index (22.9, 22.0, and 21.9 kg/m²; p = 0.028) and waist circumference (82.9, 80.8, and 80.4 cm; p = 0.041). Moreover, these significant associations persisted after adjusting for covariates. Discrepancies were observed between objective and subjective measures of masticatory function, with approximately 40% of participants showing low objective masticatory function, perceiving their chewing ability as normal. Subjective masticatory function exhibited no significant associations with anthropometric measures or sarcopenia components. Conclusions: In men, objectively measured low masticatory function was associated with reduced skeletal muscle mass and poor physical performance; in women, it was linked to higher body mass index.

This study aimed to evaluate the effects of expiratory muscle training (EMT) on respiratory muscle strength and respiratory distress during inspiratory load. Thirty-one healthy adult males were randomly divided into an EMT group who underwent EMT (n = 15) and a control group who did not undergo EMT (n = 16). The EMT group underwent EMT with a 50% load of maximum expiratory mouth pressure (PEmax) for 15 min, twice a day, every day, for 4 weeks. The parameter of respiratory muscle fatigue was a decrease in maximum inspiratory mouth pressure (PImax) and PEmax during 20 min of inspiratory load; thus, PImax and PEmax during inspiratory load were measured. Respiratory distress during inspiratory load was assessed using the Borg scale. These assessments were performed on the same subjects in each group before and after the 4 week study. In the EMT group, the PEmax values after the study were significantly higher than those before the study (p < 0.01). Furthermore, before the study, the PImax and PEmax values for the EMT group during inspiratory load were significantly lower than those before inspiratory load (p < 0.01). However, after the study, there was no difference in these values between during and before inspiratory load. In the EMT group, the Borg scale value during inspiratory load from 6 to 20 min was significantly lower after the study than before the study (p < 0.05). EMT increases expiratory muscle strength, thereby attenuating decreased respiratory muscle strength (PImax and PEmax) and respiratory distress during inspiratory load in healthy subjects.

Objective: Sports trainers contribute to the safety of adolescent athletes. The status of sports trainer services (STS) that use a trainer-certified system and trainer perceptions differ among countries, and reports from different countries are needed to promote the global use of STS. This study aimed to determine the prevalence of STS and the reasons for its use in Japanese high schools. Method: A cross-sectional study was conducted in 2022. Participants were all club activity coaches from all high schools (around 70,000 coaches) in Japan. The primary outcome was the prevalence of STS use. We obtained information on the payment status when STS was used and the reasons they were not. Results: Of the 6045 coaches included, 10.5% used STS. Volunteer trainers comprised 29.9%, and if they were paid a fee, it needed to be more for a living. The most common reason for not using STS was "no suitable person" (70.8%). Novelty: This was the first large-scale survey of the prevalence of STS use in Japanese high schools. The prevalence of STS use in Japanese high schools was low.