Journal of Sports Medicine and Physical Fitness最新文献

Background: Intra-individual factors like ovarian hormone profiles and body weight variations may influence sports practice and performance in female athletes and need to be characterized. The "Answ'Her" questionnaire was designed to develop a relevant and reproducible field-based tool to assess self-reported ovarian hormone status (natural menstrual cycle and hormonal contraceptive use) and body weight variations practices among female athletes.

Methods: French females with a regular sports practice responded (once: N.=210; twice: N.=86; thrice: N.=66) to this 73-item questionnaire reporting their ovarian hormone status, associated symptoms, perceived influence on sports practice, and body weight variations. Reproducibility was evaluated, then a descriptive cross-sectional analysis was conducted on athletes.

Results: Reproducibility was verified with 92% of Lin's correlation concordance coefficients above 0.7 and 100% of weighted agreements above 70%. Ultimately 185 female athletes (23.0±4.8 years) were included in the cross-sectional analysis. Whether they used hormonal contraceptive (46.5%) or not (53.5%), most of the athletes perceived a negative impact of their ovarian hormone status on sports practice (78.7%) and performance (84.7%). Overall, 77.3% of the athletes had experienced body weight variations that were significantly associated with an interruption of menses (>3 months) and menses irregularity over the last three years.

Conclusions: The Answ'Her questionnaire is a simple and effective reproducible field-based tool for the self-reported characterisation of female athlete ovarian hormone status and body weight variations. It could be used for a unique and simple overview of the athlete situation but also in a longitudinal design to assess the athlete's evolution and/or effectiveness of implanted training strategies.

Background: Patients underwent cyclists and triathletes test, train, and race both indoors and outdoors. However, the differences between indoor and outdoor performance remain understudied. This study aimed to analyze the relationship between indoor and outdoor performance in cycling. We investigated the influence of training environment history (indoor vs. outdoor) and application of e-sport platform on the aforementioned relationship.

Methods: Forty-three well-trained triathletes performed indoor and outdoor field tests to establish maximum sprint power (MSP) and functional threshold power (FTP). The main effects for FTP and MSP were assessed by repeated-measures ANOVA to analyze the differences between power output obtained indoors and outdoors. Multiple covariates, including training environment history and application of ZWIFT e-sport platform, were applied. Multiple linear regression was performed to investigate outdoor FTP prediction based on indoor testing.

Results: No significant differences were found for MSP and FTP obtained indoors and outdoors. However, the high individual variability in the disparity between indoor and outdoor power output (PO) in triathletes was observed. There was a statistically significant interaction between FTP and training environment history (P<0.001 for FTP expressed in W*kg^-1 and W) and FTP and BMI (P=0.042 and P=0.034 for FTP expressed in W*kg^-1 and W, respectively). The prediction formulas to establish outdoor FTP based on indoor testing had high accuracy (R2 0.80 and 0.68 for full and simple model, respectively).

Conclusions: The study underlines the crucial role of the appropriate testing environment, corresponding to the training environment and racing demands. A high individual variability in the disparity between indoor and outdoor PO at FTP are associated with training environment history and BMI. No such interactions were found for MSP.

Background: To compare the effects of aquatic aerobic and combined training on neuromuscular outcomes in patients with type 2 diabetes.

Methods: Patients with type 2 diabetes were randomized to an aerobic aquatic training (AERO), a combined aquatic training (COMBI) or a procedure control (CON) three weekly for 15 weeks. The sessions were 50 minutes long. Maximal strength and muscle endurance were assessed by the 1RM and maximum repetitions at 60% 1RM tests, respectively, in knee extension and elbow flexion exercises. Timed up and go test, testosterone, cortisol and testosterone:cortisol ratio also were evaluated.

Results: Participants had 59.0±8.2 years, 51% women. All groups increased (P<0.001) the maximal knee extension strength (Mean Difference: AERO: 21.1 kg; COMBI: 14.6 kg; CON: 4.4 kg), while only COMBI group increased (P<0.001) the maximal elbow flexion strength (Mean Difference: 2.6 kg). Muscle endurance in both exercises were increased in all groups. The Timed Up and Go test at the usual and maximal speed decreased in all groups. Testosterone were not modified in present study, while cortisol and testosterone:cortisol were improved in COMBI group.

Conclusions: Aquatic training, especially combined aquatic training, improve the neuromuscular fitness of patients with type 2 diabetes.

Background: Studies have shown a positive relationship between cardiorespiratory fitness (CRF) and executive functioning in older adults. Although this relationship has been well established, there seems to be a gap in the literature on the role of sex differences concerning CRF and executive functions. The current study aimed to assess the effect of sex in the relationship between CRF and cognition in older adults by stratifying the results to examine effects in males and females.

Methods: Ninety-six older adults (61 females) gave their written, informed consent to participate in this cross-sectional study. All participants underwent a maximal continuous graded exercise test on a cycle ergometer to assess their maximal oxygen uptake (VO2max) and a computerized Stroop task (naming, inhibition, and switching) to assess their executive functions. According to VO2max test results and the American College of Sports Medicine's guidelines, females and males were classified into higher-fit and lower-fit groups. A general linear model and estimated marginal means analyses were applied.

Results: Results showed no significant differences in the naming, inhibition and switching performance tests between male and female older adults (P>0.05).

Conclusions: Based on the observed positive relationship between CRF and executive functioning, the data of the current study supports the idea that aerobic exercise, which typically increases CRF, is well-situated to improve executive functioning in older adults, irrespective of sex.

Background: The aim of this study was to investigate the effect of normal breath and apnea swimming on acid-base balance, physiological responses and performance during high-intensity interval training in swimming.

Methods: Sixteen swimmers completed 6×50 m intervals of freestyle swimming with normal breath and apnea at maximum intensity, with 1 minute rest. Capillary blood gases (pH, PCO2, PO2, HCO3, Hct, Hb) were collected at four (4) measurement time points: 1) at rest once; 2) at rest just after the 3^rd repetition; 3) at finish; and 4) at 10 min of recovery. Heart rate (HR) during swimming, lactate acid (La) concentration and swimming time (t50) were measured.

Results: Our study showed uncompensated metabolic acidosis due to increased lactic acidosis in both breathing conditions, more pronounced in apnea, and faster swimming times in apnea without different heart rate responses.

Conclusions: Apnea during repetitive high intensity long distance interval 50 m freestyle swimming causes uncompensated metabolic acidosis but improves sprint performance.

Background: Isometric strength testing is widely applied in sports science. However, we hypothesized that traditional testing procedures with a dual focus on both peak force (PF) and rate of force development (RFD) may compromise the true assessment of early RFD measures and lower the associative value towards vertical jump performance.

Methods: Therefore, PF and RFD were assessed for 47 active participants (24 females, 23 males) with a traditional isometric midthigh pull (IMTP) protocol ("push as hard and fast as possible" over 4 s) and an RFD-specific protocol ("push as fast as possible" over 2 s). IMTP measures were compared to squat (SJ), countermovement (CMJ) and drop-jump (DJ) performance.

Results: The RFD-specific protocol provided higher RFD (P<0.05) for time domains up to 100 ms but lower PF (P<0.001). Independent of protocol, SJ and CMJ performance displayed significant, but low-to-moderate correlations with all RFD measures (r=0.30-0.52) as well as PF (r=0.44), whereas DJ did not show any correlation.

Conclusions: In conclusion, an RFD-specific protocol appears relevant for the assessment of RFD in the time domain up to 100 ms. However, the observed associations between RFD/PF measures and vertical jump performance remained low-to-moderate independent of the IMTP test protocol.

Background: Cooling devices reduce thermal strain during pre-, between-, and postexercise. However, their efficacy during moderate/intensity runs in hot conditions with airflow equivalent to the running speed remains unclear. This study assessed physiological and perceptual responses to neck and upper back fan-cooling through an air-perfused rucksack under such conditions.

Methods: Ten young men ran at 60% V̇O2peak for 30 min in 35 °C, 50% relative humidity with (FAN) and without (CON) air-perfused rucksacks with a hood in a randomized order. Headwind equal to running speed was provided in both conditions. The fan-cooling trial consisted of upper back and neck fan cooling with airflow at 4-5 m/s via two fans attached on either side of the rucksack. Rectal and skin temperatures, whole-body thermal sensation, thermal comfort, and changes in body mass were measured.

Results: Upper back skin temperature and thermal sensation were significantly lower throughout the exercise in the FAN than in the CON, whereas thermal comfort was significantly higher at 15-40 min in the FAN (all P≤0.05). Heart rate elevation during 30 min of running was attenuated in the FAN compared to that in the CON (P≤0.05). No significant differences in rectal and mean skin temperatures, or total body mass loss were observed between the two trials.

Conclusions: These results indicate that additional fan-cooling on the upper back and neck during running in uncompensable hot conditions with a headwind had limited physiological benefits. However, whole-body-based thermal sensation and comfort are partially improved with the use of an air-perfused rucksack.

Introduction: According to the PRISMA guidelines, this systematic review of randomized controlled trials examined whether Panax ginseng supplementation reduces resistance to exercise-induced muscle damage (EIMD).

Evidence acquisition: Web of Science, SPORTDiscus and Medline databases were searched from the 16^th of December 2021 to the 18^th of February 2022. Inclusion criteria were studies in humans consuming Panax ginseng that employed resistance training as the damaging muscle protocol and measured markers implicated in the etiology of EIMD (muscle damage, muscle function and muscle soreness). The PEDro risk of bias assessment tool was used to appraise the studies critically.

Evidence synthesis: Conflicting evidence was evident in markers of muscle damage, muscle function and muscle soreness. The quality assessment suggested that all studies had some level of bias.

Conclusions: From 180, six studies were included in the systematic review. The main findings suggest that Panax ginseng does not attenuate markers of EIMD following resistance training. However, research is still preliminary. Adequately powered sample sizes and well-controlled studies are warranted to clarify Panax ginseng's efficacy.

Background: The aim of the study was to determine the location and types of injuries in the lower limbs in American football players in Poland. The circumstances of the injuries were identified, with particular emphasis on the player's position on the field.

Methods: Original questionnaire to investigate 70 consecutive Polish players was used. Analyses as a whole and divided into offensive and defensive players were carried out.

Results: Overall, injuries to both lower limbs accounted for 17.1%, injuries to the right lower limb to 37.2%, and injuries to the left limb to 29%. Ankle injuries were the most common, both offensive and defensive, accounting for 58.5% and 48.3% of lower limb injuries, respectively. Injuries to muscles, tendons and ligaments were more common in defensive players (55.2%), while in offensive sprains (52.5%), fractures (19.5%), and contusions (17.1%). The incidence of lower limb injuries was higher in general during training than competitions and in the case of offensive players (14.6%).

Conclusions: Coaching American football increases the risk of foot injury, accounting for 10% of lower limb injuries. The obtained results indicate the need to strengthen the ligamentous-muscular complex of the lower limbs. Lower limb injuries are more common among offensive players than defensive. Offensive players are twice as likely to suffer from foot injuries. Lower limb injuries are more common during training, compared to competitions, both offensively and defensively.

Background: Overhead throwing can cause asymmetric physical characteristics induced by certain repeated asymmetric movements. Characterizing these physical properties could provide insights for health promotion, conditioning, and training planning. The status of asymmetric body composition and physical function in overhead throwing sports athletes remains unclear. The aim of this study was to investigate body composition asymmetries in experienced overhead throwing sports athletes.

Methods: This study included 77 college students classified into three groups, overhead throw sports, non-overhead throw sports, and non-sports experience groups, based on past and current sports activities and years of experience. A body composition analyzer was used to measure body composition variables. The asymmetry in body composition variables between limbs was evaluated using the asymmetry index. Differences between groups were compared using one-way analysis of variance and post-hoc tests.

Results: The lean muscle mass asymmetry index of the arms in the overhead throw group was significantly higher than that in the other groups. The dominant arm lean muscle mass in the overhead throw group was significantly higher than that in the other groups. However, the non-dominant arm lean muscle mass in the overhead throw group was significantly higher than that in the non-sports experience group.

Conclusions: Overhead throwing sports results in increased muscle mass in the dominant arm and produces asymmetry in muscle mass between the arms. This asymmetry may be induced by repeated and frequent asymmetrical motions. Our findings highlight the importance of characterizing the effect of sports activities on the athletes and may provide insights for conditioning regimens for them.