International journal of exercise science最新文献

No study has determined the impact a sprinting potentiating stimulus has on discus throwing performance in collegiate throwers. To test the hypothesis, that compared to a dynamic warm-up alone (DyWU), a dynamic warm-up with a multi-set sprinting potentiating stimulus (DyWU+SPR) would enhance discus throw performance. 12 NCAA Division I thrower athletes (18-25 year) randomly completed two sessions separated by at least 48 hours. One session involved a standardized dynamic warm-up (DyWU) and the other session involved a DyWU with multiple sets of a sprinting post-activation performance enhancement (PAPE) stimulus (DyWU+SPR), with both sessions followed by three trials of competition discus throws. A two-way ANOVA (warm-up x timepoint) with repeated measures was used for analyses, p < 0.05. There were no significant (p>0.05) differences between DyWU alone versus DyWU+SPR stimulus for discus throw distances at 8 min. (35.7±5.4 vs 35.0±5.5 meters, respectively; d = -0.12, trivial), 11 min. (34.8±4.5 vs 35.6±5.0 meters, respectively; d = 0.18, trivial), 14 min. (37.5±4.5 vs 36.7±4.9 meters, respectively; d = -0.19, trivial), or best throw attempt (36.2±5.1 vs 36.6±5.0 meters, respectively; d = 0.07, trivial). Within the parameters of this study, there were no differences in discus throw performance with DyWU+SPR compared to a DyWU alone in NCAA Division I throwers. Coaches, athletes, and practitioners should be aware that these results do not support the use of multiple sets of a sprinting PAPE stimulus beyond a dynamic warm-up alone to enhance discus throw performance in collegiate throwers.

Lower body positive pressure treadmills (LBPPT) have gained increasing attention due to their potential applications in sports training, rehabilitation, and biomechanics research. However, there is limited understanding of how differing body weight percentages influence gait and force production. This study aimed to investigate the relationship between force and gait parameters at different body weight percentages on a LBPPT. Twenty-seven healthy participants completed a series of walking, jogging, and running trials at three different body weight conditions: 100%, 90%, and 75%. Gait parameters, including cadence, stride length, stance time, and ground reaction force, were measured using the Digitsole Pro foot insoles and analyzed across the different conditions. Repeated measures ANOVA and pairwise comparisons were used to examine the effects of body weight percentage on the gait parameters. The results showed significant effects of BW on cadence, stride length, stance time, and impact force during running condition (p < 0.001). Jogging condition was significantly different across all % BW for all variables except ground reaction force (GRF). For walking, the only significant differences presented were for stride length on the right limb between 100% and 90% BW (p = 0.004) and 100% and 75% BW (p = 0.04) and time in stance on the left and right (p < 0.05). Pairwise comparisons revealed significant differences between the 100%, 90%, and 75% BW conditions for most gait parameters during jogging and running. These findings suggest that lower body weight percentages substantially influence gait mechanics and force production, especially as speed increases.

Adipose tissue stores energy in fat-rich adipocytes, which can produce and release several adipokines and modulate body metabolism. Exercise may induce adipokine production in adipocytes; however, the relationship between the two remains unclear. Few studies have shown the relationship between adipokines and strength training. Thus, we aimed to evaluate the acute and chronic effects of strength training (ST) on urinary adiponectin, leptin, and resistin levels. Twelve untrained young men (23.42 ± 2.67 years) were included in this study. Body composition was evaluated at baseline and after completing of the training protocol using densitometry. Training protocol consisted of three exercises with three sets of 65% of one-repetition maximum (1MR) with a pause of 90 s between sets, each exercise lasting 5 s (2 s concentric / 3 s eccentric). The sessions were carried out three times a week for 10 weeks. Urine was collected during the pre- and post-training in the first and 30th session. Adipokine levels were determined by ELISA. Urinary levels of leptin acutely increased after the first ST session, and after the last ST session. Chronic changes in the leptin levels were also found when comparing the values before the last ST and before the first ST session. Urinary adiponectin levels changed in the comparison of values before and after the last session. There was a significant increase in the adiponectin levels when comparing values after the first and last ST sessions. The levels of resistin chronically increased. Strength training can induce acute and chronic changes in urinary levels of adipokines.

This study investigates the longitudinal patterns of musculoskeletal injuries in an NCAA field hockey team, emphasizing the predictive value of index injuries on subsequent injury rates. Analyzing a dataset from a women's collegiate field hockey team, this research monitored 810 injuries across 124 athletes from 2008 to 2024. The study categorized injuries as local, nonlocal, and recurrent, employing a negative binomial regression to assess the impact of index injuries on the total number of career injuries. Results indicated that ankle sprains, hamstring strains, and back strains significantly predicted the total number of career injuries. Furthermore, the analysis revealed that the majority of subsequent injuries occurred within 69 days of the index injury, suggesting a critical window for targeted interventions. The findings underscore the need for robust longitudinal data and standardized reporting to enhance injury prevention strategies in field hockey.

This study aimed to evaluate the effectiveness of a flexible, trainee-driven training program in improving concurrent training outcomes for individuals training remotely. The study employed a repeated-measures, parallel group design with 18 participants randomized into either a control group with fixed workouts or an experimental group with flexible workout selection based on perceived readiness. Participants were recreationally trained at baseline. Over a 16-week period, both groups completed assessments of strength and endurance, including deadlift, push-ups, and a two-mile run. The results indicated no significant difference in overall fitness improvements between the two groups, with both showing meaningful progress in strength and endurance measures. However, adherence rates were notably lower in the flexible group as the study progressed, potentially due to decision fatigue. Statistical significance was set at ρ ≤ 0.05, with main effects of time showing significant improvement in fitness scores across all groups. The findings suggest that while flexible programming offers similar benefits to traditional fixed programs, it may require strategies to maintain adherence over longer periods. Practical applications include the potential for flexible training to be used effectively in remote settings, particularly for populations like military personnel with varying access to fitness resources.

[This corrects the article on p. 1191 in vol. 16, PMID: 38287936.].

Compression garments, utilized in sports and exercise for performance enhancement and recovery, lack sufficient well-controlled studies to overcome any potential placebo effect. Therefore, we tested whether wearing compressive pantyhose (CP) during the Ballet-specific aerobic fitness test (BAFT) would influence performance, recovery, physiological, and perceptual indicators. Additionally, this pilot study tested the feasibility of the research procedures and informed adjustments for the main study. Nine young classical ballerinas attended two sessions on different days: a) wearing CP (pressure of 20-30 mmHg) or b) wearing a placebo pantyhose ([PLA] no compression, containing an illusory effect) during the BAFT. We assessed heart rate (HR) and rating of perceived exertion (RPE) during the BAFT, perceived recovery (PRS), lower-limb delayed onset muscle soreness (DOMS) at Pre and 24 h Post, and standing heel-rise test performance at Pre, 30 min, and 24 h Post. No variables differed (p>0.05) between CP and PLA (e.g., HR mean over 5 BAFT phases: 178±14 bpm vs. 179±17 bpm, p=0.63; RPE 30 min post: 9.1±0.8 vs. 9.1±0.8 arbitrary units, p=0.94). However, wearing CP promoted attenuation in acute fatigue, while PLA showed a performance decrement (p<0.05) 30 min Post in the standing heel-rise test: CP 30.2±6.0 to 22.8±7.5 repetitions and PLA 36.2±11.7 to 22.9±6.3 repetitions. We conclude that CP may mitigate acute fatigue in the triceps surae muscle of amateur classical ballet dancers, making it relevant for their acute recovery, particularly in cases involving multiple daily performances. Additionally, this pilot study confirmed the feasibility of the procedures.

In addition to maximal oxygen consumption (VO2max), the Lactate Threshold (LT) is the other major determinant of aerobic exercise performance. This study examined the effects of the menstrual cycle (MC) phase on the LT in untrained females. Eight females and 8 males completed a LT test on a cycle ergometer. The tests were performed across three MC phases: early follicular (EF; menses), ovulatory (O), and mid-luteal (ML). The male participants (control group) were randomly assigned visits at similar time intervals as a regular 28-day cycle. Blood lactate was obtained during the last minute of each 3-minute stage of the LT test. The LT was determined by visual method (LT_vis), and fixed blood lactate concentrations of 2.0 mmol/L (LT_2.0mmol) and 4.0 mmol/L (LT_4.0mmol). There were no statistically significant differences in power at LT for any of the determination methods across the MC for the female participants (p>0.05) or across the time intervals for the male participants (p>0.05). The male participants tended to have higher power at LT for all three methods LT_vis (41.91W), LT_2.0mmol (44.68W), and LT_4.0mmol (55.94W). These findings support that the MC does not seem to influence power at LT in untrained naturally menstruating females.

Heart rate and heart rate variability indicate an athlete's cardiovascular recovery and autonomic balance after intense exercise. While stretching aids recovery, its effects on autonomic balance are inconsistent. Yoga's combination of postures, breathing, and relaxation may further activate the parasympathetic system, making it a promising tool for sports recovery. This study employed a crossover design to examine the effects of yoga and stretching on post 30-min session of high-intensity interval training (HIIT) recovery in male athletes. Twenty athletes of Mae Fah Luang University (Age 20.95±0.99 years old, VO2max 42.53±4.79 ml/kg/min) were given recovery methods, 15-min stretching and 15-min yoga following HIIT. Heart rate, blood pressure, respiratory rate, and heart rate variability were evaluated immediately after HIIT, 5-min, 10- min, 15-min of the recovery period, and at 24-hour after recovery. A Two-way repeated-measures analysis of variance (ANOVA) was employed to examine the interaction effects between different methods and time of recovery. A significance level of 0.05 indicated a statistically significant difference. The findings indicated a statistically significant interaction between the group and time of heart rate variability and respiratory rate (p<0.05, effect size [ES] medium). Post-hoc analysis indicated that performing yoga showed a significantly lower respiratory rate at 5-min, 10-min, and 15-min compared to stretching (p<0.05, ES large). Yoga demonstrated a noteworthy enhancement in heart rate variability during the 5-min and 10-min recovery periods in comparison to stretching. In summary, this study provides empirical evidence supporting the efficacy of yoga as a post-exercise recovery strategy following high-intensity interval training. The role of breathing, rhythmic muscle contractions, and deep relaxation in yoga appears to facilitate the recovery phase more effectively than stretching alone. This suggests incorporating yoga as an active recovery regimen.

The fitness movement in the United States has evolved substantially since its emergence in the late 20th century, with social media platforms like YouTube and TikTok now playing a pivotal role in disseminating fitness programs and associated claims. One program that has gained considerable popularity is the 12-3-30 treadmill workout (12-3-30), which involves walking at a 12% grade at 3 mph for 30 minutes. Despite widespread claims about its effectiveness in burning fat and calories, there is a lack of peer-reviewed scientific studies evaluating these claims. The present study investigated metabolic responses to 12-3-30 compared to self-paced treadmill running, with both sessions matched for total energy expenditure. Sixteen participants (7 female, 9 male) completed both sessions in a controlled laboratory setting, where metabolic data were collected using a metabolic analyzer. The measures recorded were completion time, total energy expenditure, energy expenditure rate, and substrate utilization (percentage of carbohydrate [%CHO] and fat [%FAT]). The results showed that, when matched for total energy expenditure, 12-3-30 had a significantly longer completion time, lower energy expenditure rate, higher %FAT, and lower %CHO than self-paced running. While 12-3-30 may be less time efficient than self-paced running for expending energy, it may be more advantageous for individuals aiming to increase fat utilization. The present study enhances our understanding of the metabolic demands associated with a trending fitness program and highlights the importance of scientifically evaluating such programs to provide evidence-based recommendations.