Distribution of fat, non-osseous lean and bone mineral mass in international Rugby Union and Rugby Sevens players.

Differences in the body composition of international Rugby Union and Rugby Sevens players, and between players of different positions are poorly understood. The purpose of this study was to examine differences in the quantity and regional distribution of fat, non-osseous lean and bone mineral mass between playing units in Rugby Union and Rugby Sevens. Male Rugby Union (n=21 forwards, 17 backs) and Rugby Sevens (n=11 forwards, 16 backs) players from the Australian national squads were measured using dual-energy X-ray absorptiometry. The digital image of each player was partitioned into anatomical regions including the arms, legs, trunk, and android and gynoid regions. Compared with backs, forwards in each squad were heavier and exhibited higher absolute regional fat (Union 43-67%; ±~17%, range of % differences; ±~95% confidence limits (CL); Sevens 20-26%; ±~29%), non-osseous lean (Union 14-22%; ±~5.8%; Sevens 6.9-8.4%; ±~6.6%) and bone mineral (Union 12-26%; ±~7.2%; Sevens 5.0-11%; ±~7.2%) mass. When tissue mass was expressed relative to regional mass, differences between Rugby Sevens forwards and backs were mostly unclear. Rugby Union forwards had higher relative fat mass (1.7-4.7%; ±~1.9%, range of differences; ±~95% CL) and lower relative non-osseous lean mass (-4.2 to -1.8%; ±~1.8%) than backs in all body regions. Competing in Rugby Union or Rugby Sevens characterized the distribution of fat and non-osseous lean mass to a greater extent than a player's positional group, whereas the distribution of bone mineral mass was associated more with a player's position. Differences in the quantity and distribution of tissues appear to be related to positional roles and specific demands of competition in Rugby Union and Rugby Sevens.

The effects of injury and illness on haemoglobin mass.

This study sought to quantify the effects of reduced training, surgery and changes in body mass on haemoglobin mass (Hbmass) in athletes. Hbmass of 15 athletes (6 males, 9 females) was measured 9±6 (mean±SD) times over 162±198 days, during reduced training following injury or illness. Additionally, body mass (n=15 athletes) and episodes of altitude training (n=2), iron supplementation (n=5), or surgery (n=3) were documented. Training was recorded and compared with pre-injury levels. Analysis used linear mixed models for ln(Hbmass), with Sex, Altitude, Surgery, Iron, Training and log(Body Mass) as fixed effects, and Athlete as a fixed and random effect. Reduced training and surgery led to 2.3% (p=0.02) and 2.7% (p=0.04) decreases in Hbmass, respectively. Altitude and iron increased Hbmass by 2.4% (p=0.03) and 4.2% (p=0.05), respectively. The effect of changes in body mass on Hbmass was not statistically significant (p=0.435).The estimates for the effects of surgery and altitude on Hbmass should be confirmed by future research using a larger sample of athletes. These estimates could be used to inform the judgements of experts examining athlete biological passports, improving their interpretation of Hbmass perturbations, which athletes claim are related to injury, thereby protecting innocent athletes from unfair sanctioning.

Spurious Hb mass increases following exercise.

Sensitivity of the Athlete Blood Passport for blood doping could be improved by including total haemoglobin mass (Hb(mass)), but this measure may be unreliable immediately following strenuous exercise. We examined the stability of Hb(mass) following ultra-endurance triathlon (3.8 km swim, 180 km bike, 42.2 km run). 26 male sub-elite triathletes, 18 Racers and 8 Controls, were tested for Hb(mass) using CO re-breathing, twice 1-5 days apart. Racers were measured before and 1-3 h after the triathlon. Controls did no vigorous exercise on either test day. Serum haptoglobin concentration and urine haemoglobin concentration were measured to assess intravascular haemolysis. There was a 3.2% (p<0.01) increase in Racers' Hb(mass) from pre-race (976 g ± 14.6%, mean ±% coefficient of variation) to post-race (1 007 g ± 13.8%), as opposed to a - 0.5% decrease in Controls (pre-race 900 g ± 13.9%, post-race 896 g ± 12.4%). Haptoglobin was - 67% (p<0.01) reduced in Racers (pre-race 0.48 g / L ± 150%, post-race 0.16 g / L ± 432%), compared to - 6% reduced in Controls (pre-race 1.08 g / L ± 37%, post-race 1.02 g / L ± 37%). Decreased serum haptoglobin concentration in Racers, which is suggestive of mild intravascular blood loss, was contrary to the apparent Hb(mass) increase post-race. Ultra-endurance triathlon racing may confound the accuracy of post-exercise Hb(mass) measures, possibly due to splenic contraction or an increased rate of CO diffusion to intramuscular myoglobin.

Quality control technique to reduce the variability of longitudinal measurement of hemoglobin mass.

The sensitivity of the athlete blood passport to detect blood doping may be improved by the inclusion of total hemoglobin mass (Hb(mass)), but the comparability of Hb(mass) from different laboratories is unknown. To optimize detection sensitivity, the analytical variability associated with Hb(mass) measurement must be minimized. The aim of this study was to investigate the efficacy of using quality controls to minimize the variation in Hb(mass) between laboratories. Three simulated laboratories were set up in one location. Nine participants completed three carbon monoxide (CO) re-breathing tests in each laboratory. One participant completed two CO re-breathing tests in each laboratory. Simultaneously, quality controls containing Low (1-3%) and High (8-11%) concentrations of percent carboxyhemoglobin (%HbCO) were measured to compare hemoximeters in each laboratory. Linear mixed modeling was used to estimate the within-subject variation in Hb(mass), expressed as the coefficient of variation, and to estimate the effect of different laboratories. The analytic variation of Hb(mass) was 2.4% when tests were conducted in different laboratories, which reduced to 1.6% when the model accounted for between-laboratory differences. Adjustment of Hb(mass) values using quality controls achieved a comparable analytic variation of 1.7%. The majority of between-laboratory variation in Hb(mass) originated from the difference between hemoximeters, which could be eliminated using appropriate quality controls.

Operant, open-field and tonic immobility behaviours in chickens with forebrain injections of cycloheximide or glutamate.

Chickens that had received bilateral injections of cycloheximide or glutamate into the forebrain on day 2 of life and tested 4 weeks later showed no deficit in acquisition, performance or extinction of continuously reinforced appetitive key-pecking as compared to control birds injected with saline. However, chickens that had received injections of cycloheximide and were subsequently tested in an open-field apparatus took longer to leave the first square, defaecated more, and pecked, preened and moved about less than controls. They also showed longer durations of tonic immobility. Those injected with glutamate inhibited similar behaviour but were not significantly different from controls in the open field latency to leave the first square, defaecation, or tonic immobility tests. The above treatments have previously been described as producing permanent slowed learning in chickens on a pebble-floor task. Our results suggest that learning mechanisms may not be disrupted as shown by normal performance in a simple operant task but that enhanced emotionality or fear of novelty as revealed in the open field tests may interfere with the expression of learning behaviour in some situations.

Lateralisation of function in the chicken fore-brain.

There is lateralisation of function in the chicken fore-brain. This was revealed by examining the behavioural modifications produced by administration of cycloheximide into the left or right hemisphere on Day 2 of post-hatched life. Visual discrimination learning of a task requiring a search for food was found to be performed either entirely or, at least, to a greater extent by the left hemisphere. Visual habituation learning was not found to be lateralised. The left hemisphere is more involved in auditory habituation than is the right; administration of cycloheximide to the left hemisphere slowed auditory habituation, as did bilateral administration, but treatment of the right hemisphere was ineffective. There are indications that the right hemisphere plays a more important role in response to novelty. A side-preference for response to stimuli seen by the left eye was demonstrated. These results are discussed with reference to head orientation during development in the egg.