International journal of exercise science最新文献

Energy drinks are marketed for enhancing mental and physical performance, often containing ingredients beyond caffeine. This study investigated whether an energy drink (ED), Gorilla Mind, exerted greater effects on sustained attention, mood, handgrip strength, and push-up performance than a caffeine-matched control drink (CAF) in exercise-trained individuals (n = 21, age: 22 ± 5.9 years). In a randomized, counterbalanced, crossover design, participants first completed tests assessing mood (Profile of Mood States; POMS), sustained attention (Psychomotor Vigilance Test; PVT), handgrip strength (HG), and 1-minute maximum push-up performance (PU). They then consumed either an ED or CAF drink (200mg caffeine) in a randomized order. After 45 minutes, the tests were repeated. Following a 1-week washout period, participants returned to consume the other drink and completed the same protocol. While the ED group improved reaction time (PVT), the Delta score between ED and CAF was not statistically significant (p = 0.3391). No significant differences were found between ED and CAF groups for other measures (POMS: p = 0.152, HG: p = 0.499, PU: p = 0.209). These findings suggest that the additional ingredients in the ED may not offer substantial benefits beyond caffeine for these measures in active individuals. It is important to note that the caffeine dose was, on average, less than 3.0 mg/kg body mass, which may have influenced the outcomes.

The purpose of the current study was to test the hypothesis that individual response classification for surrogate markers of cardiorespiratory fitness (CRF) will agree with response classification for VO_2peak. Surrogate markers of CRF were time to fatigue on treadmill test (TTF), time trial performance (3kTT), resting heart rate (RHR), submaximal heart rate (SubmaxHR), and submaximal ratings of perceived exertion (SubmaxRPE). Twenty-five participants were randomized into a high-intensity interval training (HIIT: n = 14) group or non-exercise control group (CTL: n = 11). Training consisted of four weeks of high-intensity interval training (HIIT) - 4x4 minute intervals at 90-95% HR_max 3 times per week. We observed poor agreement between response classification for VO_2peak and surrogate markers (agreement < 60% for all outcomes). Although surrogate markers and VO_2peak correlated at the pre- and post-intervention time points, change scores for VO_2peak were not correlated with changes in surrogate markers of CRF. Interestingly, a significant relationship (r ² = 0.36, p = 0.02) was observed when comparing improvements in estimated training performance (VO₂) and change in VO_2peak. Contrary to our hypothesis, we observed poor classification agreement and non-significant correlations for changes scores of VO_2peak and surrogate markers of CRF. Our results suggest that individuals concerned with their VO_2peak response seek direct measurements of VO₂.

The purpose of this study was to evaluate the test-retest reliability of the instrumented version of the modified Clinical Test of Sensory Interaction on Balance (i-mCTSIB) using the VirtuSense VirtuBalance System™ (VSTBalance), a virtual balance device, in healthy young adults. Fifty-four subjects aged 20-27 years (Mean age 23.07, SD ± 1.6), participated in the study. A one-group design was utilized. Three trials of the i-mCTSIB were performed on two separate days to measure the mean sway velocity of the trunk under four conditions. Within-day reliability of trials 1-3 was estimated with intraclass correlation coefficients (ICC_3,1) and between-day reliability was estimated using the averages of trials 1-3 on day 1 and day 2 (ICC_3,3). Within-day reliability was moderate on day 1 (ICC = 0.511-0.672) and day 2 (ICC = 0.539 -0.677). Between-day reliability was moderate to good (ICC = 0.705-0.810). The lower bounds of the confidence intervals of within-day reliability estimates were 0.341-0.548, while the lower bounds of the confidence interval for the between-day reliability estimates were 0.390-0.671. Reliability of the VSTBalance for balance assessment using the i-mCTSIB test is moderate to good. Between-day reliability was higher than within-day reliability. When using the VSTBalance to assess balance with the i-mCTSIB, clinicians should provide practice of each condition contained in the test to improve reliability. The higher between-day reliability as compared to within-day reliability suggests that clinicians should use the averages of three trials when assessing balance performance change across time for each condition of the i-mCTSIB test when assessing balance using the VSTBalance.

Many tactical athletes (military and emergency personnel) have fixed load carriage occupational requirements. Understanding the effects of running with common military "fighting loads" (no load to approximately 18 kg) on heart rate (HR), perceived exertion (RPE), and measuring it with accelerometers has implications for training and ensuring physical readiness of recruits. Eleven (7 male and 4 female) civilians (21.5±2.3 years, 1.83±0.09 m, and 80.7±18.5 kg) completed four, 5- minute running (8.05 kph) conditions: no external load, rifle carriage (3.5 kg), pack carriage (13.6 kg), and rifle/pack carriage (17.1 kg) in random order, while HR, RPE, and hip worn ActiGraph accelerometer step cadence, and activity counts per minute (CPM) were collected. One way 4-level analysis of variance or Friedman test explored the condition main effect on HR, RPE, step cadence, and CPM. Pairwise comparisons with Bonferroni correction determined which conditions differed from each other. HR and RPE significantly differed (p < 0.001) by load condition. No external load had the lowest HR and RPE (HR=141.8 bpm, RPE=9.4), while rifle/pack carriage had the highest (HR=160 bpm, RPE=14.8). However, rifle carriage (HR=153.7 bpm, RPE=12.3) elicited similar physiological responses as pack carriage (HR=155.0 bpm, RPE=13.6). Step cadence was equal across conditions, but CPM decreased as loads increased. Because a lighter load carried in the hands caused similar HR and RPE response to wearing a heavier pack, recruits should practice both in preparation for military or tactical occupations. Accelerometers may be used to assess step cadence, but not the increased physiological demands of external load conditions.

The COVID-19 pandemic has pushed the population to adopt increasingly sedentary lifestyles. Faced with this problem, remote training appears as a practical and inexpensive strategy to promote physically active lifestyles. The aim of this research was to compare the effects of remote versus in-person training on metabolic profiles and body composition of physically inactive adults. This research was conducted through a randomized, single-blind clinical trial with balanced block randomization. The sample consisted of 30 physically inactive subjects of both sexes between 18 and 30 years of age. The sample was selected using a voluntary public call. The 30 subjects were randomized into three groups of 10 people each. One group trained for 36 sessions remotely, and the other did so in person. The control group did not have a training plan. The variables evaluated pre- and post-intervention were body composition by bioimpedance, grip strength through dynamometry, primary outcome, and metabolic profile assessed from a capillary sample using the CARDIOCHEK equipment. In the remote training group, significant gains were evident in the variables of weight (p = 0.042, d = 1.119), muscle percentage (p = 0.032, d = 0.499), and fat percentage (p = 0.001, d = 1.132), visceral fat (p = 0.032, d = 0.424), total cholesterol (p = 0.001, d = 1.213), HDL (p = 0.001, d = 0.534), LDL (p = 0.001, d = 0.973), triglycerides (p = 0.001, d = 0.583), and grip strength (p = 0.001, d = 1.201). When comparing the effects between the remote and in-person training groups, it is evident that the improvements were similar in all variables, except for glucose, in which the in-person group had a greater value reduction.

Running shoes, and in particular insoles, are the first interface between runners and running surface. Different insole attenuation properties may vary perception of cushioning and, accordingly, the effect on muscle adaptation. The aim of this study is to find the just noticeable difference between four insole materials, and investigate the parameters of in-vitro measurement of impact testing to predict cushioning comfort. Nineteen (n = 19) male participants were recruited from the sports center at the Technical University of Munich with a mean age of 23.89 (SD = 2.31), weight of 73.52 kg (SD =3.08), and height 178.84 cm (SD =2.81). Four insole samples, one with the highest peak acceleration (EPDM =17.9g), one with the lowest (S.Tk = 8.3g) and the two materials with middle range magnitudes (IP.GL= 11.5g and S.Tn = 12.2g), were selected to use in the subjective measurement. We used the impact testing method to evaluate the in-vitro physical properties of insoles in running shoes. In addition, two parameters of peak acceleration were measured as follows: Jolt α was calculated at a slope of between 5-20 % of inertial impact force and Jolt β was calculated at a slope of between 0-88 Newtons of inertial impact force. Participants performed six pairwise comparison tests with shoes which were equipped with one of the four insoles in a random order. A minimum 6% increase in cushioning properties, notably between 11.5g (S.Tn) and 12.2g (IP.Gl), was discerned through the paired tests. In simpler terms, participants were able to detect a mere 0.7g as the just noticeable difference. In addition, our findings revealed that an increase of Jolt α and Jolt β resulted in a reduction in perception of comfort. There was a negative and significant correlation between Jolt α and perceived cushioning and, similarly, between Jolt β and perceived cushioning r (10) = -0.93, p = 0.00001. No correlation was found between peak acceleration and cushioning comfort (p = 0.1). These discoveries may facilitate a better understanding of how human adaptation can occur with different cushioning.

This study aims to identify contextual situations (score, game time, the interaction between teammates and opponents, start and restart plays) that increase the odds ratio of maintenance of ball possession and scoring a goal. Twenty professional futsal players were evaluated in seven home official matches. The games were filmed to analyze the offensive actions. In total, 828 attacking plays were analyzed. The absence of defensive pressure from the opponent resulted in a greater odds ratio (OR) for loss of ball possession (OR = 1.7, 95% CI = 1.7 to 2.2), but also increased total effectiveness (OR = 6.5; 95%CI = 2.2 to 19.5). The received fouls did not increase the total effectiveness (OR = 0.2; 95%CI = 0.01 to 4.2; p = 0.40). The court regions close to the opponent's goal area and areas where there was less defensive pressure had a higher frequency of goals (p < 0.05). The results demonstrated that shooting close to opponents' areas and having no defensive pressure were the situations with increased odds of goal-scoring. Maintaining ball possession per se did not increase the OR of goal scoring, however situations when shootings were performed with low defensive pressure could increase chances of goal scoring.

Functional movement patterns are an important aspect of everyday life, and a growing area of interest for determining the risk of injury and performance ability. Police, military, and fire personnel often carry torso-borne loads that increase the demands on the body while performing occupational tasks. The purpose of this study was to compare movement screen results in both a loaded and unloaded condition to identify potential effects that torso-borne body armor load carriage may have on tactical performance. This provided objective data on the effects that external loads may have on functional movement patterns. Twenty-four physically active participants (11 males, 13 females) volunteered and completed the Fusionetics™ Movement Efficiency Test (FMET) in two conditions: loaded (wearing a 13.5 kg tactical vest) and unloaded, in a counterbalanced order. Participants were video recorded performing these movements and scored later. The overall scores, on a scale of 0 to 100, showed a large, statistically significant decline in functional movement pattern quality from the unloaded to the loaded condition (12.6±7.3 points, p<.001, d=1.8). In the subscales, statistically significant declines (p<.001) were seen in the 2-leg squat (d=0.8), push-ups (d=1.1), shoulder movements (d=2.1), and trunk movements (d=0.9). There was no significant effect of load on the cervical movements or 1-leg squat. Overall, torso-borne body armor loading decreased functional movement pattern quality, suggesting the potential benefit of performing loaded movement screens on tactical athletes.

The purpose of this study was to confirm that blood lactate concentrations can be maintained at moderate to high steady state values during an entire interval training (IT) session (repetitions + rest). Forty-eight trained swimmers and track athletes performed four IT protocols consisting of 6-10 bouts between 1 and 3-min at ~5-10 mmol/L blood lactate concentrations with a passive recovery of 60 to 180-sec. Performance times were measured at every bout, while blood lactate concentrations and heart rate during recovery every other bout. One-way ANOVA was performed for comparisons and r-squared for the effect size (ES). Performance times were stable throughout each IT protocol (75 ± 8 and 77 ± 5-sec [swimmers and track athletes]; 67 ± 3-sec [swimmers]; 64 ± 3-sec [swimmers]; and 135 ± 6-sec [swimmers]). Despite some minor differences (p<0.05; ES, 0.28 to 0.37, large), blood lactate concentrations were maintained stable at moderate to high values during each IT protocol (5.85 ± 1.47 mmol/L; 5.64 ± 1.03 mmol/L; 9.29 ± 1.07 mmol/L; and 9.44 ± 1.12 mmol/L). HR decreased significantly from the beginning to the end of recovery (p<0.05; ES, 0.93 to 0.96, large). In conclusion, moderate to high blood lactate steady state concentrations can be sustained for ~20 to 60-min during an entire IT session (repetitions + rest) at a stable performance. This approach can optimize performance by stimulating the metabolic demands and the pace strategy during the middle section of endurance competitive events.

Resisted sprint (RS) training, such as sled or parachute towing, is commonly used for sprint training among field sport athletes. While RS training is frequently employed by athletes and coaches, there is little research on its benefits, especially compared to unresisted running (UR) training programs with similar training volumes. This systematic review and meta-analysis compared the effectiveness of RS training on acceleration compared to UR training. Potential sources were limited to peer-reviewed articles published in English prior to June 12, 2022, and gathered from the EBSCOhost, PubMed, and Web of Science online databases identified using combinations of the following terms: towing, sled, "resisted sprint," "sprint acceleration," "sprint performance," and "sprint speed." The search returned 1,159 sources, from which 15 were eligible for inclusion. Fifty effects were used to estimate the impact of RS training on initial sprint speed. Based on the cumulative results from these studies, RS training yielded a small improvement in acceleration but was not different from same volume of UR training (Hedges' d Effect Size=0.11, 95% CI: -0.01 to 0.23; p=0.08). These results do not support the use of RS training over UR training for improving initial sprint speed; however, further research should be conducted.