Characterizing the Thermal Demands and Mobility Performance During International Wheelchair Rugby Competition.

Objective: To determine the thermoregulatory responses and mobility performance of wheelchair rugby (WCR) players during international competition. Methods: Eleven male National Team WCR players volunteered for the study. Testing occurred during a four game series against international competition (temp 24.7 ± 0.7°C, relative humidity 50.1 ± 3.6%), with movement time (MT) and gastrointestinal temperature (Tgi) recorded continuously. Results: The mean maximal Tgi was 38.6 ± 0.6°C (37.9-39.7) and did not significantly differ among Low-Class, Mid-Class, and High-Class athletes (p > 0.05). Moreover, there was a strong and significant relationship between minutes (min) played per quarter of the game and change in Tgi (r = 0.36, p = 0.01). Athletes moved a total of 27:43 ± 9:40 min:seconds (s), spent a total of 15:02 ± 8.23 min:s in Zone 1 (53.5%), 8:19 ± 3:20 min:s in Zone 2 (31.7%), and 5:59 ± 1:51 min:s in Zone 3 (21.3%). There were no differences among classification in total movement time (p = 0.169) or for speed in Zone 1, Zone 2, or Zone 3 (p > 0.05). The relationship between peak forward speed and total movement time was strong (p = 0.021, r = 0.68). Conclusion: This study demonstrated that the time spent in absolute movement zones is not classification dependent, the change in core temperature is related to movement time per quarter. Furthermore, peak speeds obtained on-court were linked to overall movement time which suggests athletes should warm-up before going on court.

Cardiovascular responses to heat acclimatisation in athletes with spinal cord injury.

OBJECTIVES: To determine the effect of heat acclimatisation (HA) training on blood profile and resting cardiac function in elite athletes with spinal cord injury (SCI). DESIGN: Quasi-experimental. METHODS: Eleven athletes (10m, 1f) with SCI (C5-T3) completed a five-day isothermic HA protocol whereby gastrointestinal temperature (Tc) was elevated to and maintained at ∼38.5 degrees Celsius (°C) via intermittent exercise for sixty minutes each day. Blood samples were collected pre- and post-HA to determine changes in plasma volume (PV). Doppler ultrasound of the left-ventricular outflow tract and 2-d speckle tracking echocardiography were performed in a subset of athletes (n=5) to determine changes in indices of resting left-ventricular function and mechanics, respectively. RESULTS: Ten athletes were successfully able to raise and maintain Tc to 38.5°C. There was a non-significant increase in PV with HA training (ΔPV%: 3.0±5.4%, p=0.086). Following HA, resting HR decreased (63±4 pre-HA vs. 58±5 bpm post-HA, p=0.020), velocity time integral (21.4±2.7 vs. 23.7±3.0cm, p=0.045) and stroke volume increased (64.8±7.6 vs. 70.2±10.5mL, p=0.055). CONCLUSIONS: Our findings suggest a short-term HA protocol in athletes with SCI is safe and may induce beneficial changes in indices of resting left-ventricular function - however results are highly individualized. Future studies on HA in athletes with SCI should focus on determining mechanisms of adaptation and performance outcomes.

Physiological Considerations to Support Podium Performance in Para-Athletes.

The twenty-first century has seen an increase in para-sport participation and the number of research publications on para-sport and the para-athlete. Unfortunately, the majority of publications are case reports/case series or study single impairment types in isolation. Indeed, an overview of how each International Paralympic Committee classifiable impairment type impact athlete physiology, health, and performance has not been forthcoming in the literature. This can make it challenging for practitioners to appropriately support para-athletes and implement evidence-based research in their daily practice. Moreover, the lack of a cohesive publication that reviews all classifiable impairment types through a physiological lens can make it challenging for researchers new to the field to gain an understanding of unique physiological challenges facing para-athletes and to appreciate the nuances of how various impairment types differentially impact para-athlete physiology. As such, the purpose of this review is to (1) summarize how International Paralympic Committee classifiable impairments alter the normal physiological responses to exercise; (2) provide an overview of "quick win" physiological interventions targeted toward specific para-athlete populations; (3) discuss unique practical considerations for the para-sport practitioner; (4) discuss research gaps and highlight areas for future research and innovation, and (5) provide suggestions for knowledge translation and knowledge sharing strategies to advance the field of para-sport research and its application by para-sport practitioners.

Effect of Unintentional Boosting on Exercise Performance in a Tetraplegic Athlete.

Boosting is the induction of autonomic dysreflexia (AD) to reflexively activate otherwise dormant thoracolumbar sympathetic circuitry to "boost" the capacity of the cardiovascular system and enhance exercise performance. AD is a life-threatening condition unique to individuals with spinal cord injury (SCI) characterized by a sudden increase in sympathetic activity below the level of the SCI. Here we report on the temporal HR response to an episode of unintentional boosting during a validated field-based exercise performance test in an athlete with tetraplegia.An athlete with SCI (C6 motor-complete, sensory-incomplete) completed a 20 ×20 m repeated sprint field test on two consecutive days. During the 13th sprint on day 2, the athlete unintentionally boosted via bladder overdistension. Average HR when boosted (i.e., sprints 14-20) was considerably higher than before boosting (141 ± 4 vs 116 ± 7 bpm) and compared with corresponding sprints on day 1 (141 ± 4 bpm vs 120 ± 1 bpm). Average time to complete 20 m sprints when boosted was also faster than the corresponding sprints on day 1 (6.70 ± 0.05 s vs 6.87 ± 0.05 s).This case report highlights the immediate effect of boosting on HR and field-based exercise performance and supports the suggestion that exercise performance in athletes with SCI is limited by cardiovascular capacity.

A 20×20m repeated sprint field test replicates the demands of wheelchair rugby.

OBJECTIVES: To assess the physiological responses to, and the agreement between, a 20×20m repeated sprint field test and wheelchair rugby game play, as well as the reliability of the test. DESIGN: Cross-sectional and longitudinal. METHODS: Heart rate (HR), blood lactate ([La-]B), and ratings of perceived exertion (RPE) were collected in nineteen elite wheelchair rugby athletes before, during, and after a 20×20m repeated sprint field test and game play. Times to complete 5, 10, and 20m during the field test were also collected. RESULTS: Peak HR and peak [La-]B were positively correlated during the field test (r=0.470, p=0.043), as were peak HR and peak speed (r=0.493, p=0.031), and peak [La-]B and peak speed (r=0.559, p=0.013). During game play, peak [La-]B was correlated with peak RPE (rho=0.703, p=0.001). Intra-class correlations (ICCs) between the field test and game play were significant for peak HR (ICC=0.922, p<0.001) and peak [La-]B (ICC=0.845, p<0.001). Bland-Altman analysis revealed good agreement between HR and [La-]B obtained during the field test and game play and excellent between-day reliability of the 20×20m sprint test. CONCLUSIONS: The physiological demands of a 20×20m repeated sprint field test are similar to those of elite wheelchair rugby game play and the test is highly reliable. This simple to implement field test may be useful as a component of team selection and in assessing the effectiveness of training interventions or monitoring athletes across training phases.