Physiological and metabolic characteristics of elite tug of war athletes

Objective—To determine the aerobic power ([Image: see text] O(2)MAX), body composition, strength, muscular power, flexibility, and biochemical profile of an elite international squad of tug of war athletes. Methods—Sixteen male competitors (mean (SEM) age 34 (2) years) were evaluated in a laboratory. For comparative purposes, data were analysed relative to normative data for our centre and to a group of 20 rugby forwards from the Irish international squad. Results—The tug of war participants were lighter (83.6 (3.0) v 104.4 (1.8) kg, p<0.0001) and had less lean body mass (69.4 (2.1) v 86.2 (1.2) kg) than the rugby players and had lower than normal body fat (16.7 (0.9)%); all values are mean (SEM). Aerobic power measured during a treadmill test was 55.8 (1.6) ml/kg/min for the tug of war participants compared with 51.1 (1.4) ml/kg/min for the rugby forwards (p<0.03). A composite measure of strength derived from (sum of dominant and non-dominant grip strength and back strength)/lean body mass yielded a strength/mass ratio that was 32% greater (p<0.0001) for the tug of war group than the rugby group. Dynamic leg power was lower for the tug of war group than the rugby forwards (4659.8 (151.6) v 6198.2 (105) W respectively; p<0.0001). Leg flexibility was 25.4 (2.0) cm for the tug of war group. Back flexibility was 28.6 (1.4) cm which was lower (p<0.02) than the rugby forwards 34.2 (1.5) cm. Whereas blood chemistry and haematology were normal, packed cell volume, haemoglobin concentration, and erythrocyte volume were lower in the tug of war group than in the rugby players (p<0.05). All three haematological measures correlated with muscle mass (packed cell volume, r(2) = 0.37, p<0.0001; haemoglobin concentration, r(2) = 0.13, p<0.05; erythrocyte volume, r(2) = 0.21, p<0.01). Conclusions—The data indicate that international level tug of war participants have excellent strength and above average endurance relative to body size, but have relatively low explosive leg power and back flexibility. The data provide reference standards for the sport and may be useful for monitoring and evaluating current and future participants. Key Words: tug of war; body composition; [Image: see text] O(2)MAX; strength; power; flexibilit

Kinetic changes during a six-week minimal footwear and gait-retraining intervention in runners.

An evaluation of a six-week Combined minimal footwear transition and gait-retraining combination vs. gait retraining only on impact characteristics and leg stiffness. Twenty-four trained male runners were randomly assigned to either (1) Minimalist footwear transition Combined with gait-retraining over a six-week period ("Combined" group; n = 12) examined in both footwear, or (2) a gait-retraining group only with no minimalist footwear exposure ("Control"; n = 12). Participants were assessed for loading rate, impact peak, vertical, knee and ankle stiffness, and foot-strike using 3D and kinetic analysis. Loading rate was significantly higher in the Combined group in minimal shoes in pre-tests compared to a Control (P ≤ 0.001), reduced significantly in the Combined group over time (P ≤ 0.001), and was not different to the Control group in post-tests (P = 0.16). The impact peak (P = 0.056) and ankle stiffness reduced in both groups (P = 0.006). Loading rate and vertical stiffness was higher in minimalist footwear than conventional running shoes both pre (P ≤ 0.001) and post (P = 0.046) the intervention. There has a higher tendency to non-rearfoot strike in both interventions, but more acute changes in the minimalist footwear. A Combined intervention can potentially reduce impact variables. However, higher loading rate initially in minimalist footwear may increase the risk of injury in this condition

The relationship between physical and wellness measures and injury in amateur rugby union players

peer-reviewedObjectives To investigate factors associated with injury in amateur male and female rugby union players. Design A prospective cohort study. Setting Amateur rugby clubs in Ireland. Participants Male (n = 113) and female (n = 24) amateur rugby union players from 5 of the top 58 amateur clubs in Ireland. Main outcome measures Pre-season testing included physical tests assessing hamstring flexibility, dorsiflexion range of movement, adductor muscle strength and foot position. Wellness questionnaires assessed sleep quality (PSQI), coping skills (ACSI-28) and support levels (PASS-Q). Players were monitored throughout the season for injury. Results The time-loss match injury incidence rate was 48.2/1000 player hours for males and 45.2/1000 player hours for females. Two risk profiles emerged involving; ‘age + navicular drop + training pitch surface’ (53%) and ‘age + navicular drop + groin strength’ (16%). An inverse relationship between groin strength and groin injury was found for the ‘backs’ players (−0.307, p < 0.05). Using the PSQI, 61% of players had poor sleep quality, however no relationship between the wellness questionnaires and injury was found. Conclusion Two injury risk profiles emerged, associated with subsequent injury occurrence. Using these risk profiles, individualized prevention strategies may be designed regarding deficits in groin muscle strength and identifying foot alignment.ACCEPTEDpeer-reviewe

Selected Physiological Characteristics of Elite Rowers Measured in the Laboratory and Field and Their Relationship with Performance.

In the present study, a number of physiological variables were measured on members of the Great Britain heavyweight rowing squad in the laboratory, field and also during altitude training. The main purposes of the study were to determine which of these physiological variables were important determinants of success in rowing and to evaluate the effects of a specific phase of training on these variables. Additionally, the study sought to assess the effectiveness of different modes of training by monitoring the physiological responses and adaptations to a period of altitude training and evaluating their impact on aerobic work capacity on return to sea level. Of the 22 descriptive and physiological variables measured to determine their relationship with rowing performance, maximal oxygen uptake (VO2max) expressed in absolute terms (1.min-1) was found to be the best single predictor of rowing performance for the 6 minute (DIST6) and 2500 metre (T2500) performance tests used. Although a number of other physiological variables were found to be significantly related to rowing performance, their inclusion added little to a predictor model of performance. Analysis of the physiological responses to a 3 month phase of training revealed significant improvements in rowing economy (P0.05) improvement in aerobic work capacity, as determined by a fall in submaximal blood lactate concentrations during prolonged exercise

Low energy availability in male athletes: a systematic review of incidence, associations and effects

The Female Athlete Triad has recently been suggested to be a threat to male athletes. This review aims to examine the evidence, and associated effects, of low energy availability (LEA) in male athletes. A comprehensive search of PubMed and SPORTDiscus was performed. Three RCT and seven CS studies were included that measured energy availability and included well‐trained males. Clinical LEA (<30 kcal/kg LBM/d) or subclinical LEA (36 ± 6 kcal/kg LBM/d) was evident within all CS studies, documenting 25% of middle‐ and long‐distance runners and racewalkers and 70% of cyclists with LEA. Two out of three RCTs and three out of seven CS studies reported disrupted endocrine functioning, particularly reduced testosterone levels, in association with LEA. One CS study reported that up to 40% of cyclists with LEA had low BMD. One CS study assessed metabolic health, reporting those with suppressed levels spent more time in a severe energy deficit. This review highlights that LEA appears prevalent across male athletic populations, in particular endurance and weight class athletes, and is a potentially serious threat to bone, endocrine, and metabolic health. Future larger scale longitudinal studies, using appropriate study designs, should be undertaken to confirm these threats