International journal of exercise science最新文献

The COVID-19 pandemic and its associated restrictions placed on daily life may have negatively impacted overall physical and psychological health as well as health behaviors such as decreased physical activity and increased sedentary behavior. It is important to understand if these potential changes during the pandemic may be predictive of current health behaviors where pandemic-related restrictions are no longer being implemented. This study aimed to assess the relationships between perceived changes in physical activity, sitting, and stress during the COVID-19 pandemic to current measures of these same variables. In April 2022, participants (N = 208) completed a survey in which they indicated perceived changes in physical activity, sitting, and stress during the pandemic. Participants then self-reported their current total physical activity, daily sitting, and anxiety. Multiple Pearson correlation analyses were performed to assess the relationships between perceived measures of physical activity, sitting, and stress during the pandemic to current measures of these same variables. Greater perceived inactivity (i.e., reduced physical activity) during the pandemic was associated with lower current total physical activity (r = -0.28, p < 0.001) and greater daily sitting (r = 0.19, p = 0.007). Greater perceived sitting during the pandemic was associated with lower current total physical activity (r = -0.26, p < 0.001). Lastly, greater perceived stress during the pandemic was associated with greater current anxiety (r = 0.35, p < 0.001). This suggests that individuals who perceived negative health-related changes during the pandemic may still be impacted by persisting effects.

Exercise technique, defined as the controlled execution of bodily movements to ensure an exercise effectively targets specific muscle groups while minimizing the risk of injury, is a resistance training (RT) variable frequently highlighted as critical to successful RT program outcomes, with proper technique suggested to play a role in maximizing muscle development. This study examined the effects of externally applied momentum on RT-induced muscular adaptations in the upper extremities. Thirty young adults were recruited to participate in a within-participant design, with one limb randomly allocated to perform biceps curls and triceps pushdowns using strict form (STRICT) and the other using external momentum (CHEAT). Participants completed four sets of each exercise with 8-12 repetitions until momentary muscular failure, twice a week for eight weeks. We obtained pre-post proximal and distal measures of muscle thickness for the elbow flexors and extensors, and assessed circumference changes in the upper arms. Data were analyzed in a Bayesian framework including both univariate and multivariate mixed effect models with random effects. Differences between conditions were estimated as average treatment effects, with inferences based on posterior distributions and Bayes Factors (BFs). Results showed similar between-conditions increases for all muscle thickness sites as well as circumference measures, generating consistent support for the null hypothesis (BF = 0.06 to 0.61). Volume load was markedly greater for CHEAT compared to STRICT across each week of the intervention. In conclusion, the use of external momentum during single-joint RT of the upper extremities neither helped nor hindered hypertrophy of the target muscles.

College students are a vulnerable population at risk of developing and/or experiencing poor physical fitness and insufficient physical activity (PA) levels, both associated with poor cardiometabolic health. Thus, this study assessed the association of physical fitness and domain-specific PA levels on cardiometabolic risk factors (CMRFs) among college students. A volunteer sample of students enrolled in general health and wellness courses at a large, Northeastern U.S. institution from Spring 2023 - Spring 2024 (n=1418, 69.0% male, 89.9% non-Hispanic White) completed an objective health assessment as part of a required course assignment. CMRFs (e.g., cholesterol, blood pressure, fasting blood glucose, triglycerides, waist circumference), cardiorespiratory fitness (e.g., VO₂ max), and markers of muscular strength and endurance (e.g., pushups, curl ups, hand grip, sit and reach) were assessed. Participants were then invited to complete a subjective health assessment (e.g., demographics, PA). Separate, unadjusted linear regressions examined the association of physical fitness and domain-specific PA levels (e.g., moderate and vigorous PA, active transportation PA, muscle-strengthening, meeting PA guidelines) on CMRFs, by biological sex. Socio-demographics of race/ethnicity, sexual orientation, semester standing, and grade point average served as covariates in separate, adjusted models to assess potential associations. Among males and females, cardiorespiratory fitness and markers of muscular strength and endurance were significantly associated with CMRFs, while PA levels and socio-demographics were not. Tailored screening approaches may provide students with the required support to reduce later-life adverse coronary events. Future work is required to improve our understanding of the potential role socio-demographics play in CMRFs among young adults.

Type 2 diabetes mellitus (T2D) is a major health problem worldwide having life-threatening complications causing mortality and a rise in prevalence. Effective treatment strategies are vital for managing diabetes and its associated complications including cardiovascular disease (CVD), nephropathy, neuropathy, and retinopathy. This systematic review aims to evaluate effective treatment approaches, focusing on the comparative effects of exercise and GLP-1 receptor agonists (GLP-1RAs) in T2D rat models. Current pharmacological therapies primarily target glycemic control and insulin sensitivity. However, there is a growing concern in non-traditional approaches that involve exercise and GLP-1 RAs for managing T2D. These therapies are crucial as they have the potential to improve pancreatic β-cell efficiency to secrete insulin, control blood glucose levels, decrease insulin resistance, and manage diabetes-related issues. Studies were searched in seven electronic databases including Google Scholar, MEDLINE, PubMed, Cochrane Library, Scopus, PEDro, and Web of Science from inception till 2024. Out of 16,500 documents retrieved between 2020 and 2024, 58 full-text articles were assessed in detail, and 13 studies met the inclusion criteria that include Male Wistar, Male Sprague Dawley and Adult female Wistar albino rats weighing 200-250 grams. These experimental studies examined the effects of exercise and different GLP-1 RAs on 103 diabetics and 103 non-diabetic rats. Overall, synthesized findings revealed a promising effect on glucose control, insulin sensitivity, and metabolic health in diabetic rats. Further research is needed to elucidate the cellular and molecular mechanism(s) through which exercise and GLP-1 RAs manage T2D and its associated complications including cardiovascular disease (CVD), nephropathy, neuropathy, and retinopathy.

Originally designed to mitigate skull fractures and traumatic brain injuries in hockey players, hockey helmets have now become a critical focus for further research due to the rise in mild traumatic brain injuries. With the sport's evolution introducing stronger and faster players, new approaches that incorporate facial shielding in helmet technology and enhance athletes' neck strength are needed to reduce concussion risks. This study pursued two primary objectives. Firstly, it sought to determine if a hockey helmet's stiffness fluctuated at different contact locations during static compression with the inclusion of facial shielding. Secondly, it examined the influence of impact location, facial protection type, and neck stiffness on head injury risk during simulated dynamic impacts, gauged by the Gadd Severity Index (GSI). The findings revealed that helmet stiffness varied across locations, and a significant three-way interaction was observed between facial shielding, impact location, and neckform stiffness level concerning GSI measures at p < 0.05. Further analysis unveiled significant two-way interactions between impact location and facial shielding across neck strength levels at p < 0.05. These outcomes underscore the critical role of facial shielding, neck strength and impact location, in averting brain injuries in hockey. The results carry practical implications for helmet manufacturers, standards bodies, coaches, and players, urging a comprehensive approach to helmet design and player safety.

The purpose of this study was to evaluate the impact of once-weekly sprint training on running economy (RE) and leg stiffness (LS) in highly trained athletes (12 M, 13 F, mean age 24.8 ± 7.1). Participants were recruited based on weekly exercise volume (minimum 4 hours) and athletic ability calculated by World Athletics score (minimum 500). RE and LS were evaluated at three velocities before and after 12 weeks of once-weekly sprint training. On average, participants experienced a non-statistically significant improvement in RE (average percent change -2.0 ± 5.6%, -1.2 ± 5.2%, -1.0 ± 4.6%, p = 0.389, 0.269, 0.272, Cohen's d = 0.21, 0.18, 0.17), and a statistically significant improvement in LS (12.59 ± 9.2%, 11.49 ± 10.9%, 15.67 ± 11.2%, p = 0.019, 0.027, 0.011, Cohen's d = 0.61, 0.56, 0.68) at the three running velocities. Interestingly, the improvement in LS was significantly influenced by a reduction in vertical displacement during the gait cycle (-17.7 ± 11.7%, -15.7 ± 12.2, -17.3 ± 13.4%, p < 0.001, = 0.001, = 0.001, Cohen's d = 1.10, 0.93, 0.91). Changes in RE and LS were significantly different when data were analyzed by exercise volume during the intervention period (p < 0.05). The present study demonstrates that LS, independently shown to improve performance and RE, can be improved by sprint training in highly trained athletes. Additionally, the average participant improvement in RE suggests that sprint training may lead to statistically significant improvement with an increase in participants and tighter participant training control.

Several recent reports have indicated positive health benefits of consuming (-)-epicatechin-rich cocoa products. Postmenopausal women are predisposed to reduced metabolism due to decreased levels and activity of the sex hormones estrogen, progesterone, and estradiol. The purpose of this study was to investigate the influence of dark chocolate consumption on resting and exercise metabolism in postmenopausal women. Using a randomized, double-blind design, 26 postmenopausal participants were assigned to a 30-day supplementation with 20-g per day of 72% dark chocolate (DC) or calorically matched white chocolate (WC). Before supplementation, participants underwent two control trials for assessments (PRE1, PRE2) of resting energy expenditure (REE) and exercise energy expenditure (EEE). Following the PRE2 assessment, participants were randomized and supplemented for 30 days, after which they repeated the assessments for REE and EEE. PRE1 and PRE2 REE and EEE were not significantly different within or between groups (REE: PRE1 DC 1215± 170, WC 1127 ± 174, p=0.662; PRE2 DC 1211 ± 174, WC 1145 ± 165 kcal/d, p=0.720; EEE: PRE1 DC 3.67 ± 0.72, WC 3.40 ± 0.81, p=0.665; PRE2 DC 3.41 ± 0.88, WC 3.39 ± 0.73kcal/min, p=0.373). Post-supplementation REE was significantly increased by 3.2% in the DC group (Pre-Post change: DC 38.6 ± 49, WC -15 ± 31.2 kcal per day, p =0.039, Cohen's d= 0.724 [95% CI: 0.078, 1.513]). These results indicate that DC supplementation in postmenopausal women was associated with a significant 3.2% increase in REE with no significant influence on EEE.

People living with and beyond breast cancer (LWBBC) experience different side effects relative to the type of medical treatments they received which may influence their needs for additional supportive care. Investigating people LWBBC's needs according to treatment regimen may guide decision making about supportive care priorities. The study's objectives were to identify individuals LWBBC's needs for supportive care and to determine exercise program participation facilitators according to treatment type. A survey assessing the needs for supportive care and exercise facilitators was distributed on the Facebook pages of five non-profit Canadian cancer organizations for three months. Needs and facilitators were assessed according to the combination of treatment type received including chemotherapy, radiotherapy or a combination of both. A convenience sample of 214 women LWBBC (mean age 50 ± 11 years) responded to the survey. Most (84%) participants reported searching for supportive care, especially exercise or psychological support for pain/fatigue management and improvement of psychological well-being. Higer proportions of women receiving chemotherapy (86-95%) were searching for supportive care compared to women not receiving chemotherapy (70%). Psychological support was the most searched supportive care among women receiving both chemotherapy and radiotherapy, while exercise program was most sought out by women receiving only one of these two treatment types. Low cost (47%) and accessibility to a supervised program (46%) were the most important exercise program facilitators for participants during treatment. Needs of women LWBBC seemed to diverge according to received treatment and should be considered when tailoring supportive care for these individuals.

The purpose of this study was to compare eccentric strengthening to static stretching for increasing hamstring flexibility. Sixty-three asymptomatic participants were recruited via convenience sampling. Nineteen participants did not meet the inclusion criteria, thus leaving 44 participants. Inclusion criteria included hamstring tightness defined using the passive knee extension test (PKE). Exclusion criteria included a history of any lower extremity injury, including hamstring injury, within the past 12 months. Participants were randomized into one of three groups: Nordic Hamstring Exercise (NHE) eccentric group, static hamstring stretching, or control group. Hamstring flexibility was assessed, via the PKE, at baseline, 3 weeks, and six weeks. Between and within group differences in hamstring flexibility were assessed using a mixed model ANOVA. The analysis yielded a significant time × group interaction ( < 0.05). At six weeks, both the static stretching and eccentric group had greater improvements in flexibility compared the control group (p < 0.001). This study adds to the body of research by demonstrating the positive effect of eccentric training on gross muscle length. It revealed the NHE results in similar increases in hamstring flexibility when compared to static hamstring stretching. As a result, either stretching or eccentric training can be used effectively to address hamstring flexibility deficits.

The isometric mid-thigh pull (IMTP) test using the traditional bar grip (BAR) is a reliable and effective measure of strength performance in different populations. In addition, IMTP performance has been linked to jump performance. Recent research has shown that the pelvic belt (PEL) IMTP method produces higher absolute and relative peak force values than the Bar IMTP method. However, limited scientific data has examined the PEL IMTP method performance data and its relationship to dynamic strength and sports performance. The study aimed to provide a more robust comparison between the BAR and PEL IMTP methods and examine the relationship between these methods and several countermovement jump (CMJ) performance variables. Thirty healthy National Collegiate Athletic Association (NCAA) Division III athletes volunteered for this study. Each participant was asked to attend and complete four separate lab sessions utilizing a bilateral force platform. The results of this study demonstrated that peak force and relative peak force were significantly (p ≤ .05) greater during the PEL IMTP method than during the BAR IMTP method. Further, force development increased similarly in both the BAR and PEL IMTP methods, although there were no differences between the methods (p>.05). Lastly, Pearson's product-moment correlations demonstrated a medium and significant (p ≤ .05) relationship between CMJ and PEL IMTP variables. In conclusion, the PEL IMTP can measure lower body force performance capabilities. Further, PEL IMTP variables can be used to predict jump performance and, therefore, may be used for assessment and training purposes.