International journal of exercise science最新文献

The study aimed to compare the effect of three precooling techniques (internal, external, and combined) on the time to reach exhaustion in active men. Eight active men (23 ± 2 yrs; 178 ± 6 cm; 73 ± 11 kg) participated] in 4 exhaustive test sessions with a minimum power output of 40Wmax. Sessions included consumption of 7.5 grams of ice water with a temperature of -1 degree per kilogram of body weight, cold towels (4-6°C) used to cool the skin surface], a combination of ice water consumption and a towel cooling, and a control session in which subjects cycled to reach exhaustion without any cooling techniques. Data was analyzed using a mixed-method (treatment time) repeated-measures ANOVA was with significance accepted at p<0.05. The skin surface temperature in the combined session and towel session was significantly lower than the ice session (p<0.001). The central temperature in the combined and ice slurry sessions was significantly lower at the beginning and end of the activity compared to the towel session (p<0.01). Exhaustion time and distance traveled in the combined session were significantly longer compared to the ice slurry and control sessions (p<0.01). In the towel session, exhaustion time was significantly greater] than the control session (p <0.04). The rate of sweating in the ice slurry session was significantly lower than the control session (p <0.01). The perception of pressure in the combined session was significantly lower than the ice slurry and control sessions (p<0.05). The results indicate that a combination of two techniques (internal and external cooling) can have a greater effect on measures of endurance performance.

The object was to assess the effects of adding exercise to a 36-hour fast on the inflammatory cytokines IL-6, TNF-α, and MCP-1. The study was a randomized crossover design with counterbalanced conditions in community members living near a single academic institution. Participants included twenty healthy adults (11 male). The intervention consisted of two 36-h water-only fasts, one of which was initiated with a bout of treadmill exercise. Venous blood was taken at baseline, 12-h, 24-h, and 36-h of fasting. Area under the curve and timepoint analyses were computed. The area under the curve for MCP-1 was 210.4 ± 61.4 pg/ml higher in the fasting combined with exercise condition compared to fasting alone (F = 4.69, p = 0.04). No difference between conditions was observed in areas under the curve for IL-6 (F = 0.02, p = 0.88) or TNF-α (F = 3.74, p = 0.06). MCP-1 concentrations decreased over the course of both conditions (F=19.77, p < 0.01) with much of the reduction taking place between hours 12 and 24 (F=19.77, p < 0.01). Concentrations of IL-6 remained unchanged (F = 0.85, p = 0.48) while TNF-α increased (F=8.60, p < 0.05) in both conditions. A single fast has a mixed impact on the cytokines MCP-1, TNF-α and IL-6. MCP-1 decreases, while TNF-α fluctuates in a diurnal pattern, and IL-6 experiences no change during a water-only fast. Adding exercise to the beginning of a fast diminishes the decline in MCP-1 but has no impact on TNF-α or IL-6.

Fitness and rehabilitation professionals commonly use yoga training for improving balance, flexibility, and mental health in populations of all ages. However, little is known about how chair yoga, a specific form of yoga, would impact physical and mental health in older adults. The purpose of this case series was to explore the feasibility and benefits of an 8-week chair yoga class for older adults in an independent living facility. Four participants (ages 77-92 years) performed chair yoga interventions once a week for 8 weeks. Interventions included, but were not limited to, 10 minutes of warm-up including breathwork and range of motion, 10-15 minutes of peak movements including forward folds, bicycles, bird dog, squats, and boat pose, and 5-10 minutes of cool down including backbends, camel, seated cross, gentle spinal flexion and extension, and breathwork. Participants were tested prior to the start and re-tested at the end of 8 weeks. Outcome measures included the Tinetti Balance and Gait Assessment and the short form health survey (SF-36). Improvements were made for all participants in the Tinetti and all except one participant improved on one or more of the SF-36 subscales. Chair yoga training was feasible for four older adults with comorbidities and may have additional benefits for functional mobility and strength. Further research studies with larger sample sizes are needed to continue exploring the benefits of this understudied intervention for older adults.

This study aimed to examine weekly variations and within-subject relationships between internal training intensity (ITI), perceived recovery (TQR), neuromuscular performance (CMJ), and perceived muscle soreness (PMS) during a four-week preseason period in professional soccer players. Twenty-three soccer players (age 24.8 ± 4.4 years; height 182 ± 7 cm; body mass 74.6 ± 6.7 kg) classified as Tier 3 athletes from the Croatian Second Soccer League were monitored using session rating of perceived exertion, TQR scales, countermovement jump tests, and PMS questionnaires. A significant reduction in ITI and concurrent improvement in TQR scores were observed across the preseason, with the highest intensity in week 1 and the lowest recovery in week 2. CMJ height performance declined during peak fatigue but rebounded as training intensity tapered. Repeated-measures correlations revealed negative associations between weekly ITI and TQR of the following week (r_rm = -0.72), and between ITI and CMJ (r_rm = -0.55), indicating that greater training intensities may impair both perceptual and neuromuscular recovery. The training stimulus-recovery difference index was positively associated with next-day TQR, suggesting it may serve as a sensitive marker of session-level readiness. These findings highlight the interplay between intensity, recovery, and fatigue, emphasizing the utility of low-cost subjective and objective tools for monitoring preseason responses and guiding individualized training strategies in elite soccer settings.

Implicit biases are unconscious, internally held beliefs shaped by cultural norms, societal structures, and personal experiences and are often related to societal constructs such as race, gender, age, body shape, and ability. The aim of this study was to explore the relationship between social identity, industry role, and implicit biases in fitness professionals. Participants (n=296) were randomly assigned two implicit association tests (IATs): disability, weight, gender, skin-tone, or age. IATs measured implicit bias through word and pictorial associations and timed response to word/picture stimuli. Interviews (n=25) were conducted to further examine participants' psychosocial beliefs and experiences related to biases. Quantitative data revealed moderate preferences for younger, lighter skinned, thin, male individuals concurrent with a strong preference for able bodies. Certified personal trainers and strength and conditioning coaches held significantly stronger preferences towards younger people compared to participants with other certifications. Older participants were significantly more likely to prefer White, able-bodied, thin individuals compared to their younger counterparts. Black, Indigenous, and People of Color (BIPOC) participants and participants certified as personal trainers reported a significantly greater gender bias compared to White participants and those with other certifications. Interviews revealed themes including unacknowledged biases, body aesthetics conflict, negative/positive weight associations, and negative/positive reactions to bias-related discourse. In this study's sample of fitness professionals, both quantitative and qualitative data revealed preferences for the dominant body type (e.g., young, White, thin, able-bodied, and male). Addressing these biases is an imperative step in upholding the quality of care that clients receive.

Transgender people may opt for the use of sex steroids and, in some cases, hormone blockers, which can lead to changes in body fat distribution. The aim of this study was to verify the accuracy of anthropometric equations to estimate the body density (BD) of transgender men who are undergoing Gender-Affirming Hormone Therapy (GAHT). Four transgender men (25-32 years old), who had performed GAHT for at least six months and used the hormone testosterone cypionate participated in the study. The reference criteria for BD was air displacement plethysmography (ADP). In addition, BD was estimated using anthropometric equations for both male and female sexes (Durnin & Womersley, 1974; Jackson & Pollock 1980; Lohman, 1981). The body fat percentage (%BF) was estimated by the Siri equation. For two participants (Cases 1 and 3), the equations for males underestimated the %BF, while only for Case 3 the equation for both sexes underestimated the %BF. For the other two participants (Cases 2 and 4), all equations overestimated the %BF. Of note, one participant undergoing GAHT for six months showed a %BF assessed by ADP like values obtained using equations for cisgender women, while those with longer time on GAHT presented similar %BF obtained by ADP to obtained by equations developed for cisgender men. In conclusion, the results of this study indicate the need to develop specific anthropometric equations for the transgender population. In addition, the time on GAHT of the transgender person seems to be a critical factor.

This study aimed to evaluate the reliability and predictive validity of specific athletic running drills: A-skip, B-skip, bounding step, and jumps, in relation to sprint performance over 5 m and 20 m distances. Sixty-three young males (mean age: 21.3 ± 2.1 years; body height: 183 ± 6.5 cm; body weight: 77 ± 9.3 kg) were enrolled in the study. Running drill performance was recorded on an athletics track using high-speed cameras and evaluated based on predefined criteria and a scoring system. Reliability was assessed using intraclass correlation coefficients (ICC) and coefficients of variation (CV). Predictive validity was determined via Pearson correlations and multiple linear regression analyses. The results indicated good to excellent inter-rater reliability for A-skip (ICC = 0.897) and jumps (ICC = 0.9), while B-skip and bounding step showed good reliability (ICC = 0.808 and 0.874, respectively). The 20 m sprint demonstrated excellent reliability (ICC = 0.969, CV = 2.07%), while the 5 m sprint had good reliability (ICC = 0.863, CV = 3.58%). B-skip emerged as the strongest predictor for both sprint distances, with significant negative associations (5 m: β = -0.531, p < 0.01; 20 m: β = -0.322, p < 0.05). These findings suggest that specific drills, particularly B-skip, demonstrate high inter-rater reliability and moderate predictive validity as indicators of short-sprint performance, with B-skip showing the strongest association. Coaches and practitioners can use these drills to enhance training programs to improve acceleration and speed over short distances.

Performing training sessions in hypoxia leads to a decrease in effort quality. The inter-effort recovery intermittent hypoxia model seems to ensure training session performance. The aim of this study is to investigate the effects of sprint interval exercise under normoxic (NOR), continuous hypoxic (HYP), and inter-effort hypoxic (IEH) conditions on force parameters. Seven swimmers (age: 26.04 ± 4.64 years) volunteered and performed one session of the 10 × 30-s all-out tethered swimming efforts with 4-min passive recovery intervals for each condition. Considering the simulated altitude at F_iO₂ = 0.13 and NOR at F_iO₂ = 0.209. The sessions were separated at least 48 hours. The peak force (PF), mean force (MF), impulse, fatigue index (FI) and percentage mean force relative to peak force (PF_PERC) were determined for each effort. The force parameters were higher on IEH (PF: Δ = 21.32 N; MF: Δ = 9.65 N; impulse: Δ = 626.78 N·s) and HYP (PF: Δ = 15.80 N; MF: Δ = 6.92 N; impulse: Δ = 621.77 N·s) in relation of the NOR (p < 0.001). PF_PERC evidenced lower values in IEH in relation to HYP (Δ= 3.1 %, p = 0.017). The HYP and IEH condition can be considered a model that enhances performance in force parameters compared to the NOR condition.

Small-sided games (SSG) are often used as a multifunctional form of specific training that allows development of various key components during soccer training. The main goal of this research was to determine the differences in internal and external load of different small-sided games (SSG) during preseason. The secondary goal was to analyze specific technical demands during these SSG. Twelve players of the First Croatian Junior League (U19) participated in this research in the fourth week of the preparatory period for the competitive season 2019/2020. Testing was conducted on two separate days with a day of rest in-between. Internal (IL) and external load (EL) variables and some technical demands were observed in the research. Significant differences in IL and EL were found between different types of SSG. Overall, IL (primarily HRmax (F=4.24, p<0.05, η²=0.44) and 90-100%Hrmax (F=5.18, p<0.01, η²=0.37) and EL (primarily TD (F=3.50, p<0.05, η²=0.28) and WR (F=6.26, p<0.01, η²=0.41) increased during 5vs.5 with GK (goalkeeper) series. On the other hand, greater EL (WR (F=11.43, p<0.001, η²=0.51), 2.1-3.0 m/s (F=7.03, p<0.001, η²=0.39) was observed in regular 6vs.6 while some IL parameters (%HRmax (F=6.07, p<0.01, η²=0.36) and HRmax (F=8.60, p<0.001, η²=0.44) were higher in two 6vs.6 GK series. In terms of technical demands, incidences of the PASS, RECEIVE and TURN variables were on average higher in 5vs.5 and 6vs.6 compared to 5vs.5GK and 6vs.6GK. To conclude, different SSG generated different IL and EL outcomes, especially with the addition of goalkeeper. Also, SSG could be used as a useful training tool for pre-season training in order to improve functional abilities while adding specific match-like situations for players.

This study was to examine the effect of a mental training program, including a combination of autogenic training and imagery, on a number of mental skills and on the development of personality traits - psychological hardiness as well as conscientiousness, openness to experience, and neuroticism - in Adolescent male volleyball players. 60 adolescent male volleyball players (aged 15-17) participated in a two-group, pretest-posttest design. The experimental group (n = 30) completed 8-week mental skills training program, including imagery, self-talk, attention control, and relaxation, while the control group (n = 30) followed regular training. Psychological hardiness and selected personality traits were measured pre- and post-intervention using validated scales, and data were analyzed with mixed-design ANOVA and effect sizes. result show significant improvements in psychological hardiness (commitment, control) and personality traits (conscientiousness, openness to experience) in the experimental group (p < 0.01), with modest decreases in neuroticism. Large effect sizes (Cohen's d = 0.57-1.19; partial η² = 0.07-0.37) highlight the practical impact of the intervention compared to the control group, which showed minimal changes. Structured mental skills training significantly enhanced psychological hardiness, conscientiousness, and openness, modestly reduced neuroticism, and demonstrated practical impact, supporting its integration into adolescent male volleyball players' holistic development programs.