Activity profiles of elite wheelchair rugby players during competition

To quantify the activity profiles of elite wheelchair rugby and establish classification-specific arbitrary speed zones. Additionally, indicators of fatigue during full matches were explored. Methods: Seventy-five elite wheelchair rugby players from eleven national teams were monitored using a radio-frequency based, indoor tracking system across two international tournaments. Players who participated in complete quarters (n = 75) and full matches (n = 25) were included and grouped by their International Wheelchair Rugby Federation functional classification: group I (0-0.5), II (1.0-1.5), III (2.0-2.5) and IV (3.0-3.5). Results: During a typical quarter, significant increases in total distance (m), relative distance (m·minˉ¹), and mean speed (m·sˉ¹) were associated with an increase in classification group (P < 0.001), with the exception of group III and IV. However, group IV players achieved significantly higher peak speeds (3.82 ± 0.31 m·sˉ¹) than groups I (2.99 ± 0.28 m·sˉ¹), II (3.44 ± 0.26 m·sˉ¹) and III (3.67 ± 0.32 m·sˉ¹). Groups I and II differed significantly in match intensity during very low/low speed zones and the number of high-intensity activities in comparison with groups III and IV (P < 0.001). Full match analysis revealed that activity profiles did not differ significantly between quarters. Conclusions: Notable differences in the volume of activity were displayed across the functional classification groups. However, the specific on-court requirements of defensive (I and II) and offensive (III and IV) match roles appeared to influence the intensity of match activities and consequently training prescription should be structured accordingly

Validity and Reliability of an Inertial Sensor for Wheelchair Court Sports Performance

The purpose of the current study was to determine the validity and reliability of an inertial sensor for assessing speed specific to athletes competing in the wheelchair court sports (basketball, rugby, and tennis). A wireless inertial sensor was attached to the axle of a sports wheelchair. Over two separate sessions, the sensor was tested across a range of treadmill speeds reflective of the court sports (1.0 to 6.0 m/s). At each test speed, ten 10-second trials were recorded and were compared with the treadmill (criterion). A further session explored the dynamic validity and reliability of the sensor during a sprinting task on a wheelchair ergometer compared with high-speed video (criterion). During session one, the sensor marginally overestimated speed, whereas during session two these speeds were underestimated slightly. However, systematic bias and absolute random errors never exceeded 0.058 m/s and 0.086 m/s, respectively, across both sessions. The sensor was also shown to be a reliable device with coefficients of variation (% CV) never exceeding 0.9 at any speed. During maximal sprinting, the sensor also provided a valid representation of the peak speeds reached (1.6% CV). Slight random errors in timing led to larger random errors in the detection of deceleration values. The results of this investigation have demonstrated that an inertial sensor developed for sports wheelchair applications provided a valid and reliable assessment of the speeds typically experienced by wheelchair athletes. As such, this device will be a valuable monitoring tool for assessing aspects of linear wheelchair performance

Wheelchair tennis match-play demands: effect of player rank and result.

To examine the heart-rate (HR) response and court-movement variables during wheelchair tennis match play for high- (HIGH) and low- (LOW) performance-ranked players. Analysis of physiological and movement-based responses during match play offers an insight into the demands of tennis, allowing practical recommendations to be made. Fourteen male open-class players were monitored during tournament match play. A data logger was used to record distance and speed. HR was recorded during match play. Significant rank-by-result interactions revealed that HIGH winners covered more forward distance than HIGH losers (P < .05) and had higher average (P < .05) and minimum (P < .01) HRs than LOW winners. LOW losers had higher average (P < .01) and minimum (P < .001) HRs than LOW winners. Independent of result, a significant main effect for rank was identified for maximum (P < .001) and average (P < .001) speed and total (P < .001), reverse (P < .001), and forward-to-reverse (P < .001) distance, with higher values for HIGH. Independent of rank, losing players experienced higher minimum HRs (P < .05). Main effects for maximum HR and actual playing time were not significant. Average playing time was 52.0 (9.1) min. These data suggest that independent of rank, tennis players were active for sufficient time to confer health-enhancing effects. While the relative playing intensity is similar, HIGH players push faster and farther than LOW players. HIGH players are therefore more capable of responding to ball movement and the challenges of competitive match play. Adjustments to the sport may be required to encourage skill developmental in LOW players, who move at significantly lower speeds and cover less distance

Mucosal immune responses during court training in elite tetraplegic athletes

Closed Access. This article was published in the journal, Spinal Cord [© International Spinal Cord Society] and the definitive version is available from Nature Publishing Group at: http://dx.doi.org/10.1038/sc.2012.47Study design: Experimental study. Objectives: To examine salivary secretory immunoglobulin A (sIgA) responses and a-amylase activity during court training in highly trained tetraplegic athletes. Setting: Loughborough, UK. Methods: Seven highly trained wheelchair rugby athletes with tetraplegia performed two separate wheelchair rugby court training sessions, lasting 23 and 41.5min, respectively, with either an aerobic or an interval focus. Timed, unstimulated saliva samples were obtained pre, post and 30min post exercise and analysed for sIgA and a-amylase. Furthermore, blood lactate concentration and rating of perceived exertion (RPE) immediately after training were measured. Results: sIgA secretion rate and a-amylase were unaffected by exercise during both sessions. However, the increases of sIgA concentration (30 min post exercise: þ67±29%) during the aerobic session were accompanied by decreases in saliva flow rate ( 35±22%). Athletes’ physiological responses to exercise document the highly strenuous nature of the sessions, with blood lactate concentrations reaching 8.1±1.0 and 8.7±1.6mmol l 1 and RPE reaching 18(17,18) and 16(15,17) for the aerobic and the interval session, respectively. Conclusion: Acute bouts of highly strenuous exercise do not have negative impacts on the mucosal immune response in tetraplegic athletes, nor do they influence the production of a-amylase, a marker of sympathetic nervous activity. This contrasts responses previously observed in able-bodied athletes. The disruption of the sympathetic nervous system may prevent the downregulation of sIgA secretion rate following intense exercise, which is a response previously observed in able-bodied athletes