The purpose of this study was to examine the associations of vitamin D status with athletic performance and blood-borne markers in adolescent athletes. This cross-sectional study included forty-seven Taekwondo athletes, aged 15–18 years old. Athletic performance was assessed using maximal oxygen consumption (VO_2max), Wingate anaerobic power test, vertical jump, agility T-test, lower limb muscle strength, and fatigue resistance. Blood samples were collected to assess serum 25-hydroxyvitamin D [25(OH)D], free-testosterone, cortisol, creatine kinase, and urea. One-way ANOVAs were applied using Bonferroni adjusted alpha levels, which was 0.02 (i.e., 0.05/3). Multiple linear regressions analyses as well as Pearson and partial correlation analyses were used to examine the relationship among 25(OH)D concentration, athletic performance, and blood-borne markers. The participants 25(OH)D concentration were ranged from 16 to 73.25 nmol/L, indicating that 74.5% of the adolescent athletes have vitamin D insufficiency or deficiency. The vitamin D status did not show any significant effects on the performance factors or blood-borne markers. Serum 25(OH)D concentration was positively correlated with mean power output (r = 0.359, p < 0.05) and relative mean power output (r = 0.325, p < 0.05) after adjusting for bone age, height, weight, training experience, lean body mass, and fat mass. However, 25(OH)D concentration was not associated with other performance-related factors and blood-borne markers. In addition, multiple linear regressions analyses revealed that serum 25(OH)D concentration were not significant predictors of athletic performance in adolescent athletes. In conclusion, vitamin D status is weakly correlated with anaerobic capacity; moreover, the underlying mechanisms of how vitamin D influence anaerobic performance is unclear in the present study. Nevertheless, the importance of vitamin D on health benefits should not be underestimated, especially during growth periods.

Background: Adhesive capsulitis occurs with synovial inflammation and capsular fibrosis in the glenohumeral joint, leading to restriction of joint motion and pain. Heat therapy modalities, which aim at modifying dense collagenous tissues are commonly practiced interventions for patients with adhesive capsulitis; however, the effectiveness of ultrasound deep heat therapy (UST) on adhesive capsulitis is still unclear. Purpose: This systematic review and meta-analysis study was conducted to evaluate the effects of UST on the improvement of pain and glenohumeral joint function in adhesive capsulitis compared to (1) no treatment or placebo, and (2) any other therapeutic modalities. Methods: A literature search was carried out in January 2021 in Cochrane Central Register of Controlled Trials, PubMed, EMBASE, PEDro, Web of Science, and Google Scholar. The main outcomes of interest were self-reported pain scores, disability scores, and the range of motion. This study was conducted based on the guidelines of the PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analyses) protocols, using random-effects models. Results: Seven studies were included in the systematic review with five studies forming the basis for meta-analyses. The effects of UST in patients with adhesive capsulitis were compared with placebo, shockwave therapy, corticosteroid injection, platelet-rich plasma injection, or cryotherapy. The results indicated that UST significantly improved pain scores when performed together with exercise and/or other physical modalities compared to placebo; however, whether UST provides benefits for the improvement of disability and/or the range of motion was uncertain in the present results. Conclusions: The present findings suggest that UST as a co-intervention combined with other physical modalities is an effective means of improving the overall pain in patients with adhesive capsulitis.

This study examined whether different combinations of ambient temperature and relative humidity for the effective wet bulb globe temperature, in conjunction with two different levels of clothing adjustment factors, elicit a similar level of heat strain consistent with the current threshold limit value guidelines. Twelve healthy, physically active men performed four 15-min sessions of cycling at a fixed rate of metabolic heat production of 350 watts. Each trial was separated by a 15-min recovery period under four conditions: (1) Cotton coveralls + dry condition (WD: 45.5 °C dry-bulb, 15% relative humidity); (2) Cotton coveralls + humid condition (WH: 31 °C dry-bulb, 84% relative humidity); (3) Protective clothing + dry condition (PD: 30 °C dry-bulb, 15% relative humidity); and (4) Protective clothing + humid condition (PH: 20 °C dry-bulb, 80% relative humidity). Gloves (mining or chemical) and headgear (helmet or powered air-purifying respirator) were removed during recovery with hydration ad libitum. Rectal temperature (Tre), skin temperature (Tsk), physiological heat strain (PSI), perceptual heat strain (PeSI), and body heat content were calculated. At the end of the 2-hr trials, Tre remained below 38 °C and the magnitude of Tre elevation was not greater than 1 °C in all conditions (WD: 0.9, WH: 0.8, WH: 0.7, and PD: 0.6 °C). However, Tsk was significantly increased by approximately 2.1 ± 0.8 °C across all conditions (all p ≤ 0.001). The increase in Tsk was the highest in WD followed by PD, WH, and PH conditions (all p ≤ 0.001). Although PSI and PeSI did not indicate severe heat strain during the 2-hr intermittent work period, PSI and PeSI were significantly increased over time (p ≤ 0.001). This study showed that core temperature and heat strain indices (PSI and PeSI) increased similarly across the four conditions. However, given that core temperature increased continuously during the work session, it is likely that the American Conference of Governmental Industrial Hygienist’s TLV^® upper limit core temperature of 38.0 °C may be surpassed during extended work periods under all conditions.

Wearable activity trackers have gained popularity among individuals who want to track their physical activity (PA). The features of wearable tracking technology that are known to facilitate positive behavior changes such as self-monitoring and social connectedness) are well documented; yet, the existing evidence is not conclusive in the literature requiring further investigation. This study was an 8-week pilot randomized controlled study examining the effectiveness of PA intervention incorporating a wearable activity tracker’s online connectivity feature. Forty participants were equally randomized into either an individual-based (n = 20) or a connected group (n = 20). A Jawbone UP24 tracker was provided to all participants in both groups as a means of self-monitoring PA for eight weeks, but the connected group was additionally instructed to share their PA levels with the others using the accompanying smartphone application. Participants’ weekly step counts were evaluated each week to examine the change in PA. Participants’ biometric variables such as body weight, body mass index, waist circumference, blood pressure, and psychological status, including self-efficacy (SE) and exercise motivation (EM), were measured from both groups before and after the intervention period. Additionally, the social support questionnaire (SSQ) was measured among the connected group. The statistical significance level was set at <0.05. The average step counts for eight weeks were significantly increased only in the connected group (p < 0.001). Significant differences in step count improved from the baseline to week 8 in the connected user group (p < 0.01), but only baseline vs. week 7 in the individual users. Also, no significant interaction effects for biometric variables, EM, and SE were founded. However, SSQ was significantly improved in the connected user group (p < 0.001). PA intervention combining a wearable activity tracker and online social connectivity feature shows a greater effectiveness of promoting PA than a wearable tracker alone

Introduction: The method of limits (MLI) and method of level (MLE) are commonly employed for the quantitative assessment of cutaneous thermal sensitivity. Thermal sensation and thermal comfort are closely related and thermal sensations evoked from the peripheral thermoreceptors play an important role in thermoregulatory response to maintain normal body temperature. The purpose of this study was to compare the regional distribution of cutaneous warm and cold sensitivity between MLI and the method of sensation magnitude (MSM). Method: Twenty healthy men completed MLI and MSM to compare the regional distribution of cutaneous warm and cold sensitivity in the thermal neutral condition. The subjects rested on a bed in a supine position for 20 min. Next, the cutaneous thermal sensitivity of ten body sites was assessed by the means of MLI and MSM for both warmth and cold stimuli. Results: The absolute mean heat flux in MLI and thermal sensation magnitude in MSM showed significantly greater sensitivity to cold than to warm stimulation (p < 0.01), together with a similar pattern of regional differences across ten body sites. Both sensory modalities indicated acceptable reliability (SRD%: 6.29–8.66) and excellent reproducibility (ICC: 0.826–0.906; p < 0.01). However, the Z-sore distribution in MSM was much narrower than in MLI, which may limit the test sensitivity for the detection of sensory disorders and/or comparison between individuals. Conclusion: The present results showed that both MLI and MSM are effective means for evaluating regional cutaneous thermal sensitivity to innocuous warm and cold stimulations to a strong degree of reliability and reproducibility.

Remote ischemic preconditioning (RIPC) has been shown to minimize subsequent ischemia-reperfusion injury (IRI), whereas obesity has been suggested to attenuate the efficacy of RIPC in animal models. The primary objective of this study was to investigate the effect of a single bout of RIPC on the vascular and autonomic response after IRI in young obese men. A total of 16 healthy young men (8 obese and 8 normal weight) underwent two experimental trials: RIPC (three cycles of 5 min ischemia at 180 mmHg + 5 min reperfusion on the left thigh) and SHAM (the same RIPC cycles at resting diastolic pressure) following IRI (20 min ischemia at 180 mmHg + 20 min reperfusion on the right thigh). Heart rate variability (HRV), blood pressure (SBP/DBP), and cutaneous blood flow (CBF) were measured between baseline, post-RIPC/SHAM, and post-IRI. The results showed that RIPC significantly improved the LF/HF ratio (p = 0.027), SBP (p = 0.047), MAP (p = 0.049), CBF (p = 0.001), cutaneous vascular conductance (p = 0.003), vascular resistance (p = 0.001), and sympathetic reactivity (SBP: p = 0.039; MAP: p = 0.084) after IRI. However, obesity neither exaggerated the degree of IRI nor attenuated the conditioning effects on the measured outcomes. In conclusion, a single bout of RIPC is an effective means of suppressing subsequent IRI and obesity, at least in Asian young adult men, does not significantly attenuate the efficacy of RIPC.