The effect of eccentric exercise velocity on selected measures of muscle function and soreness of the Human elbow flexors in untrained males and females

Eccentric contractions, where a muscle is repeatedly lengthened while generating torque, result in decreased muscle function and muscle soreness. This study was designed to determine whether there was a difference in muscle response of the elbow flexors from untrained subjects (n = 12) between a bout of high intensity eccentric exercise at 30°•s-1 (LVE) compared to the equivalent at 210°•s-1 (HVE). Subjects performed 120 seconds of eccentric exercise of the elbow flexors using a Cybex 6000 Isokinetic Dynamometer. At 30°-s-1, a total of 30 repetitions were required whilst at 210°•s-1, 210 contractions were performed (at a 1:7 work/rest ratio). Both exercise bouts resulted in significant decrements in isometric and dynamic strength measures (

Validity and reliability of an incremental double poling protocol in cross-country skiers

This study determined the validity and reliability of an incremental double poling protocol performed on a Concept II ski-ergometer and validated this against an existing treadmill ski-striding protocol. Ten well-trained male cross-country skiers (age: 19 ± 1.4 y; height: 182 ± 72 cm; body mass: 76.0 ± 10.8 kg, whole body VO2Peak: 5.2 ± 1.0 L.min-1; upper body VO2Peak: 4.6 ± 1.0 L.min-1; upper body:lower body ratio: 87.2 ± 5.6%) performed four VO2Peak tests; one treadmill ski-striding test and three double poling ski-ergometer tests over five days. Test-retest reliability of the ski-ergometer protocol was determined for maximal oxygen consumption (VO2peak). The ski-ergometer test showed excellent reliability for VO2Peak (L.min-1) (coefficient of variation [CV] = 1.9%, 95% confidence limit [95% CL] [1.2, 4.7]; r = 1.00, [0.96, 1.00]) and UBPPeak (W) (CV = 1.4%, [0.9, 3.4]; r = 1.00, [0.97, 1.00]). Very strong correlations existed between the ski-ergometer and the ski-striding protocol for VO2Peak (r = 0.95, [0.76, 0.99]). The upper body ski-ergometer test provided valid and reliable measurements of ski-specific upper body aerobic power in well-trained male cross-country skiers

Anthropometric characteristics, upper-body strength, and sprint paddling performance in competitive surfers

The present study examined the potential differences in anthropometric characteristics, upper-body strength, and sprint paddling performance between youth and senior competitive surfers. Twenty competitive male surfers (19.1±6.8 years, 168.2±11.3 cm, 61.7±13.6 kg) were assessed for stature, mass, arm-span, ∑ 7 site skinfold thickness, Lean-Mass Ratio (LMR, ∑ 7 site skinfold/kg body-mass), pronated pull-up 1 repetition maximum (1 RM) and sprint paddling performance from a stationary start to 15 m. Independent t-tests were used to compare potential differences between youth (n:10) and senior group (n:10) of competitive surfers, with Cohen’s Effect Size (d) applied to reflect the magnitude of any differences observed. Senior surfers were not different from youth surfers for ∑ 7 site skinfold thickness, yet had greater stature (p\u3c0.001, d=2.7) and mass (p\u3c0.001, d=2.8). Consequently, the composite lean mass ratio (body-mass/∑ 7 site skinfold thickness, LMR) was greater (p=0.001, d=1.7) in senior competitive surfers. The senior surfers were faster in the 0-15 m sprint paddle test (p\u3c0.001, d=2.9), possessed higher peak paddling velocity (p\u3c0.001, d=2.3) and had greater absolute 1 RM pull-up strength (p\u3c0.001, d=2.8) and 1 RM pull-up strength relative to body-mass (1 RM pull-up mass/subjects body-mass) (p\u3c0.001, d=2.2). The results of this study suggest that practitioners working with competitive surfers should consider the importance of sprint paddle performance in surfers, and the need to optimize lean mass and relative strength, as these factors appear to distinguish between surfers of higher and lower athletic development and competitive level in the surfing population

Weight loss strategies in combat sports and concerning habits in mixed martial arts

Context: Combat sports are typically divided into weight classes, and body-mass manipulation to reach a weight class is commonplace. Previous research suggests that weight loss practices in mixed martial arts (MMA) may be more extreme than in other combat sports. Purpose: To investigate the magnitude of weight loss and the prevalence of weight loss strategies in different combat sports. Methods: Competitors (N = 637) from Brazilian jiu-jitsu, boxing, judo, MMA, Muay Thai/kickboxing, taekwondo, and wrestling completed an online questionnaire seeking information regarding their weight loss practices. Results: Body-mass manipulation was commonly undertaken by all combat-sport athletes, with a particularly high incidence of gradual dieting, increased exercise, and fluid restriction. Skipping meals was higher in taekwondo and wrestling (84%) compared with the other combat sports (∼58%), whereas training in heated rooms and forced oral fluid loss (spitting) was higher in wrestling (83% and 47%, respectively) compared with other combat sports (∼45% and ∼19%, respectively). MMA athletes reported the highest usage of sauna (76%) and water loading (67%) while also reporting the second-highest use of training in rubber/plastic suits (63%). Conclusions: Body-mass manipulation was present in all combat sports, with the prevalence and magnitude of acute weight loss greater in MMA. The incidence of and practices reported will help support staff be fully aware of the variety of methods these athletes and coaches may use to achieve weight loss. Additionally, the results could aid regulatory bodies in the further development of policies on weight cutting

Reviewing the current methods of assessing hydration in athletes

Background Despite a substantial body of research, no clear best practice guidelines exist for the assessment of hydration in athletes. Body water is stored in and shifted between different sites throughout the body complicating hydration assessment. This review seeks to highlight the unique strengths and limitations of various hydration assessment methods described in the literature as well as providing best practice guidelines. Main body There is a plethora of methods that range in validity and reliability, including complicated and invasive methods (i.e. neutron activation analysis and stable isotope dilution), to moderately invasive blood, urine and salivary variables, progressing to non-invasive metrics such as tear osmolality, body mass, bioimpedance analysis, and sensation of thirst. Any single assessment of hydration status is problematic. Instead, the recommended approach is to use a combination, which have complementary strengths, which increase accuracy and validity. If methods such as salivary variables, urine colour, vital signs and sensation of thirst are utilised in isolation, great care must be taken due to their lack of sensitivity, reliability and/or accuracy. Detailed assessments such as neutron activation and stable isotope dilution analysis are highly accurate but expensive, with significant time delays due to data analysis providing little potential for immediate action. While alternative variables such as hormonal and electrolyte concentration, bioimpedance and tear osmolality require further research to determine their validity and reliability before inclusion into any test battery. Conclusion To improve best practice additional comprehensive research is required to further the scientific understanding of evaluating hydration status

The current state of weight-cutting in combat sports

In combat sports, athletes are divided into categories based on gender and body mass. Athletes attempt to compete against a lighter opponent by losing body mass prior to being weighed (i.e., \u27weight-cutting\u27). The purpose of this narrative review was to explore the current body of literature on weight-cutting and outline gaps for further research. Methods of weight-loss include energy intake restriction, total body fluid reduction and pseudo extreme/abusive medical practice (e.g., diuretics). The influence of weight-cutting on performance is unclear, with studies suggesting a negative or no effect. However, larger weight-cuts (~5% of body mass inh) do impair repeat-effort performance. It is unclear if the benefit from competing against a smaller opponent outweighs the observed reduction in physical capacity. Many mechanisms have been proposed for the observed reductions in performance, ranging from reduced glycogen availability to increased perceptions of fatigue. Athletes undertaking weight-cutting may be able to utilise strategies around glycogen, total body water and electrolyte replenishment to prepare for competition. Despite substantial discussion on managing weight-cutting in combat sports, no clear solution has been offered. Given the prevalence of weight-cutting, it is important to develop a deeper understanding of such practices so appropriate advice can be given