The hypocretin/orexin antagonist almorexant promotes sleep without impairment of performance in rats.

The hypocretin receptor (HcrtR) antagonist almorexant (ALM) has potent hypnotic actions but little is known about neurocognitive performance in the presence of ALM. HcrtR antagonists are hypothesized to induce sleep by disfacilitation of wake-promoting systems whereas GABAA receptor modulators such as zolpidem (ZOL) induce sleep through general inhibition of neural activity. To test the hypothesis that less functional impairment results from HcrtR antagonist-induced sleep, we evaluated the performance of rats in the Morris Water Maze in the presence of ALM vs. ZOL. Performance in spatial reference memory (SRM) and spatial working memory (SWM) tasks were assessed during the dark period after equipotent sleep-promoting doses (100 mg/kg, po) following undisturbed and sleep deprivation (SD) conditions. ALM-treated rats were indistinguishable from vehicle (VEH)-treated rats for all SRM performance measures (distance traveled, latency to enter, time within, and number of entries into, the target quadrant) after both the undisturbed and 6 h SD conditions. In contrast, rats administered ZOL showed impairments in all parameters measured compared to VEH or ALM in the undisturbed conditions. Following SD, ZOL-treated rats also showed impairments in all measures. ALM-treated rats were similar to VEH-treated rats for all SWM measures (velocity, time to locate the platform and success rate at finding the platform within 60 s) after both the undisturbed and SD conditions. In contrast, ZOL-treated rats showed impairments in velocity and in the time to locate the platform. Importantly, ZOL rats only completed the task 23-50% of the time while ALM and VEH rats completed the task 79-100% of the time. Thus, following equipotent sleep-promoting doses, ZOL impaired rats in both memory tasks while ALM rats performed at levels comparable to VEH rats. These results are consistent with the hypothesis that less impairment results from HcrtR antagonism than from GABAA-induced inhibition

Physical characteristics underpinning lunging and change of direction speed in fencing

Lunge velocity (LV) and change of direction speed (CODS) are considered fundamental to success during fencing competitions; investigating the physical characteristics that underpin these is the aim of this study. Seventy fencers from the British Fencing National Academy took part and on average (± SD) were 16.83 ± 1.72 years of age, 178.13 ± 8.91 cm tall, 68.20 ± 9.64 kg in mass and had 6.25 ± 2.23 years fencing experience. The relationship between anthropometric characteristics (height, arm-spam and adductor flexibility) and measures of lower-body power (bilateral and unilateral countermovement jump height and reactive strength index) were examined in their ability to influence LV and CODS. In testing the former, fencers lunged (over a self-selected distance) to and from a force plate, where front leg impact and rear leg propulsive force was quantified; the lunging distance was divided by time to establish LV. CODS was measured over 12 m involving shuttles of between 2 and 4 m. Results revealed that LV and CODS averaged at 3.35 m/s and 5.45 s respectively and in both cases, standing broad jump was the strongest predictor (r = 0.51 and -0.65 respectively) of performance. Rear leg drive and front leg impact force averaged at 14.61 N/kg and 3-times bodyweight respectively, with single leg jumps revealing an asymmetry favoring the front leg of 9%. In conclusion, fencers should train lower-body power emphasizing horizontal displacement, noting that this seems to offset any advantage one would expect fencers of a taller stature to have. Also, the commonly reported asymmetry between legs is apparent from adolescence and thus also requires some attention

Ecological validity of Session RPE method for quantifying internal training load in Fencing

Session rating of perceived exertion (sRPE) is known to significantly relate to heart rate (HR) based methods of quantifying internal training load (TL) in a variety of sports. However, to date this has not been investigated in fencing and was therefore the aim of this study. TL was calculated by multiplying the session rating of perceived exertion (sRPE) with exercise duration, and through Heart rate (HR) -based methods calculated using Banister’s and Edward’s TRIMP. Seven male elite foil fencers (Mean ± SD: Age = 22.3 ± 1.6 years, height = 181.3 ± 6.5 cm, body mass = 77.7 ± 7.6 kg) were monitored over the period of one competitive season. The sRPE and HR of 67 training sessions and three competitions (87 poule bouts and 12 knockout rounds) were recorded and analysed. Correlation analysis was used to determine any relationships between sRPE and HR-based methods, accounting for individual variation, mode of training (footwork drills vs. sparring sessions) and stage of competition (poules vs. knockouts). Across two footwork sessions, sRPE, Banister’s and Edward’s TRIMP were found to be reliable, with coefficient of variation values of 6.0, 5.2 and 4.5% respectively. Significant correlations with sRPE for individual fencers (r = 0.84 – 0.98) and across mode of exercise (r = 0.73 – 0.85) and competition stages (r = 0.82 – 0.92) were found with HR-based measures. sRPE is a simple and valuable tool coaches can use to quantify TL in fencing

The ball in play demands of international rugby union

Objectives: Rugby union is a high intensity intermittent sport, typically analysed via set time periods or rolling average methods. This study reports the demands of international rugby union via global positioning system (GPS) metrics expressed as mean ball in play (BiP), maximum BiP (max BiP), and whole match outputs. Design: Single cohort cross sectional study involving 22 international players, categorised as forwards and backs. Methods: A total of 88 GPS files from eight international test matches were collected during 2016. An Opta sportscode timeline was integrated into the GPS software to split the data into BiP periods. Metres per min (m.min-1), high metabolic load per min (HML), accelerations per min (Acc), high speed running per min (HSR), and collisions per min (Coll) were expressed relative to BiP periods and over the whole match (>60min). Results: Whole match metrics were significantly lower than all BiP metrics (p < 0.001). Mean and max BiP HML, (p < 0.01) and HSR (p < 0.05) were significantly higher for backs versus forwards, whereas Coll were significantly higher for forwards (p < 0.001). In plays lasting 61s or greater, max BiP m.min-1 were higher for backs. Max BiP m.min-1, HML, HSR and Coll were all time dependant (p < 0.05) showing that both movement metrics and collision demands differ as length of play continues. Conclusions: This study uses a novel method of accurately assessing the BiP demands of rugby union. It also reports typical and maximal demands of international rugby union that can be used by practitioners and scientists to target training of worst-case scenario's equivalent to international intensity. Backs covered greater distances at higher speeds and demonstrated higher HML, in general play as well as 'worst case scenarios'; conversely forwards perform a higher number of collisions

Competition intensity and fatigue in elite fencing

As yet, no studies have characterised fencing competitions. This was investigated in nine elite male foilists across two competitions, where countermovement jump (CMJ) height, testosterone (T), cortisol (C), alpha-amylase (AA) and immunoglobulin A (IgA), were obtained. Heart rate (HR) was measured throughout competitions and blood lactate (BL) and rating of perceived exertion (RPE) were measured post bouts. Average (± SD) scores for RPE, BL and HR (average, max and percentage of time ≥ 80% HRmax) were highest in the knockout bouts compared to poules (8.5 ± 1.3 vs. 5.7 ± 1.3, 3.6 ± 1.0 vs. 3.1 ± 1.4 mmol/L, 171 ± 5 vs. 168 ± 8 bpm, 195 ± 7 vs. 192 ± 7 bpm, 74 vs. 68%) however, only significant (p .05), increased throughout competition and dropped thereafter. While responses of C, AA and IgA showed a tendency to increase during competition and drop thereafter (T and T:C doing the opposite), no significant differences were noted for any analyte. Results suggest that fencing is a high-intensity anaerobic sport, relying on alactic energy sources, however, some bouts evoke BL values of ≥ 4 mmol/L and thus derive energy from anaerobic glycolysis. High HR’s appear possible on account of ample within and between-bout rest. The small competition load associated with fencing competitions may explain the non-significant findings found

The effects of a single whole-body cryotherapy exposure on physiological, performance and perceptual responses of professional academy soccer players following repeated sprint exercise

In professional youth soccer players, the physiological, performance and perceptual effects of a single whole body cryotherapy (WBC) session performed shortly after repeated sprint exercise were investigated. In a randomized, counter-balanced and crossover design, 14 habituated English Premier League academy soccer players performed 15 x 30 m sprints (each followed by a 10 m forced deceleration) on two occasions. Within 20 min of exercise cessation, players entered a WBC chamber (Cryo: 30 s at -60°C, 120 s at -135°C) or remained seated (Con) indoors in temperate conditions (~25°C). Blood and saliva samples, peak power output (countermovement jump) and perceptual indices of recovery and soreness were assessed pre-exercise and immediately, 2 h and 24 h post exercise. When compared to Con, a greater testosterone response was observed at 2 h (+32.5 ± 32.3 pg·ml-1, +21%) and 24 h (+50.4 ± 48.9 pg·ml-1, +28%) post-exercise (both P=0.002) in Cryo (trial x treatment interaction: P=0.001). No between trial differences were observed for other salivary (cortisol and testosterone/cortisol ratio), blood (lactate and Creatine Kinase), performance (peak power output) or perceptual (recovery or soreness) markers (all trial x treatment interactions: P>0.05); all of which were influenced by exercise (time effects: all P<0.05). A single session of WBC performed within 20 min of repeated sprint exercise elevated testosterone concentrations for 24 h but did not affect any other performance, physiological or perceptual measurements taken. While unclear, WBC may be efficacious for professional soccer players during congested fixture periods