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

Effect of Repeated, On-Field Sprints on Kinematic Variables in Wheelchair Rugby Players

OBJECTIVE

The aim of the study was to evaluate the influence of repeated sprints on kinematic performance and propulsion variables during the acceleration and constant peak velocity phases in wheelchair rugby players classified as defensive (low point in defensive [LP-D]) or offensive players (high point in offensive [HP-O]).

DESIGN

Twenty-two players (13 LP-D and 9 HP-O) performed 6 × 20-m repeated sprint field tests. We calculated peak wheelchair velocities, propulsion phase times, deceleration phase times, cycle times, and left-right velocity asymmetry of the best and last sprints during the acceleration and constant peak velocity phases, the rate of decline in performance variables between the best and the last sprint and a fatigue index.

RESULTS

Peak velocities during the acceleration and constant peak velocity phases and mean velocity over the whole sprint were significantly higher during the best than last sprint. Peak velocities were higher during the acceleration and constant peak velocity phases for the best and last sprint for HP-O. The rate of decline in peak velocity during the constant peak velocity phase was higher for LP-D. Fatigue index and rate of decline in velocities and sprint time were higher for LP-D.

CONCLUSIONS

Performance variables and the rate of decline in performance variables depended on functional capacity and wheelchair type.

Impact of floor covering on wheelchair rugby players: analysis of rolling performance

Introduction

Despite the increased interest in indoor wheelchair sports in many countries, research on the effect of floor coverings on sports performance is limited. Currently, there are no specific guidelines for covering characteristics for wheelchair sports, whether for competitive or recreational purposes. This study aimed to determine the impact of floor coverings on the biomechanical parameters of manual wheelchair propulsion for wheelchair rugby practice.

Methods

Ten wheelchair rugby players performed 6 maximum-velocity sprints over 20 meters, with a 20-second recovery time between sprints, on 3 different coverings, using their personal sports wheelchairs. The coverings were: wood parquet, Gerflor TX System Endurance®, and a plastic synthetic covering (balatum). Performance and propulsion technique variables were collected using inertial measurement units (265 Hz, Kinvent, France). Additionally, rolling resistance quantification tests were conducted on each covering.

Results

Rolling resistance was lowest on the wood parquet, with an average value of 3.98 ± 0.97 N. Best sprint performance was achieved on the wood parquet. The fatigue index on the parquet was significantly lower than on the balatum (p < 0.05).

Discussion

Our results highlight that floor surface influences both performance and propulsion technique variables. Therefore, we recommend performing wheelchair rugby training on wood parquet to optimize performance. It is also important to consider the impact of different coverings on sprint performance when organizing player rotations to maintain a high level of competition during tournaments.

Reliability of anaerobic and aerobic mobility performance tests used in wheelchair rugby, wheelchair basketball and wheelchair tennis: A systematic review

BACKGROUND

Understanding the reliability and validity of field-based mobility and performance tests used within the wheelchair sports of basketball (WCB), rugby (WCR) and tennis (WCT) can assist in understanding an athletes' physiological state, training effects, and/or assist with optimising their wheelchair-user interface.

PURPOSE

To examine, evaluate and synthesize current aerobic and anaerobic field-based mobility and performance tests used in WCB, WCR and WCT.

METHODS

A systematic search was performed according to PRISMA guidelines. Studies were included if they investigated performance tests in WCB, WCR and WCT and reported reliability.

RESULTS

Twenty-one studies covering 45 mobility/performance tests were included (anaerobic, n = 35; aerobic, n = 10), with agility and repeated sprints (n = 13) being the most common, followed by linear-sprints (n = 11). Repeated sprint ability (n = 2) and submaximal field-tests (n = 2) were the least frequent. Intra-class correlations among all tests ranged from 0.62 to 0.99, with agility and repeated sprints being 0.65-0.98, followed by values of 0.62-0.99 for linear-sprint, 0.96-0.99 for repeated sprints and 0.85-0.97 for submaximal field-tests.

CONCLUSION

The most frequently measured performance tests were anaerobic tests focusing on agility and repeated sprints. Given the low number of aerobic tests in WCB, WCR and WCT, future research should focus on reliable and valid ways to measure and track performance.

Reliability of a Submaximal Field Test in Wheelchair Rugby

The aim was to investigate the test-retest reliability of performance and physiological variables of a submaximal wheelchair rugby field test. Eight trained wheelchair rugby athletes with a spinal cord injury (age: median 40, interquartile range 6.9 y; body mass: median 77.7, interquartile range 23.9 kg) performed a submaximal field test two times with a duration of 41 min, split up into four sets of eight min. Each set included eight laps with one eight-meter sprint (SP8) and one four-meter sprint (SP4). The absolute and relative reliability and the performance decrease (fatigue) across the sets were investigated. The examined variables were sprinting time, heart rate, and RPE. The measured parameters showed moderate (peak heart rate ICC3,1=0.663, peak rate of perceived exertion ICC3,1=0.718), good (SP4 ICC3,1=0.874), and excellent (mean heart rate ICC3,1=0.905, SP8 ICC3,1=0.985) test-retest reliability. Fatigue was observed for SP8 in test 2 between set 2/3 and set 2/4. For test 1 a significant decrease of performance for SP4 was found between set 2/3, set 2/4 and between set 3/4. In conclusion the submaximal field test showed moderate to excellent reliability for all measured parameters. The observed fatigue seems to be not clinically relevant. The test can be recommended to assess the effects of training or interventions.

Validity of a Wheelchair Rugby Field Test to Simulate Physiological and Thermoregulatory Match Outcomes

The purpose of the study was to verify the criterion-validity (concurrent) of an existing and reliable, submaximal wheelchair Rugby (WCR) field test by examining the correlations of selected measures of physical performance between the field test and real games. Therefore, ten WCR athletes were observed during two WCR real games and during completing the field test two times. Total distance, mean and peak velocity, playing time, number of sprints, sprints per minute, mean and maximal heart rate, body core temperature (Tc), sweat rate, body weight loss, rate of perceived exertion and thermal sensation were measured. Values were correlated with the data observed by completing the field test two times separated by seven days. The results showed significant correlations between games and field tests for sweat rate (r = 0.740, p < 0.001), body weight loss (r = 0.732, p < 0.001) and the increase of Tc (r = 0.611, p = 0.009). All other correlations were not significant. For perceptual responses Bland−Altman analysis showed data within the limits of agreement. Descriptive statistics showed similarity for mean velocity and total distance between tests and games. In conclusion the study provides the first indications that the submaximal field test seems comparable with the game outcomes in terms of increase in Tc, covered distance, mean velocity and perceptual responses. Nevertheless, more research and additional validation are required.

Influence of Wheelchair Type on Kinematic Parameters in Wheelchair Rugby

Introduction

In wheelchair rugby, players use either an offensive or defensive wheelchair depending on their field position and level of impairment. Performance of wheelchair rugby players is related to several parameters, however it is currently unclear if differences in performance are related to wheelchair type or no: the effect of wheelchair type on performance variables has not been evaluated. The aim of this study was to compare offensive and defensive wheelchairs on performance variables during a straight-line sprint.

Methods

Thirteen able-bodied people performed two 20 m sprint trials: one with an offensive and one with a defensive wheelchair. Data were collected using inertial measurement units fixed on the wheelchair. Peak wheelchair velocities and left-right asymmetries in peak wheel velocities were measured during the acceleration and constant peak velocity phases. Sprint time, cycle frequency, and mean and maximum velocity were calculated over the entire sprint.

Results

The peak velocities of the first 2 pushes (acceleration phase) were significantly higher with the defensive than the offensive wheelchair (p &lt; 0.04 and p &lt; 0.02). Mean and maximum sprint velocity were significantly higher (p &lt; 0.03 and p &lt; 0.04, respectively) with the defensive wheelchair. Cycle frequency and asymmetry did not differ between wheelchairs.

Conclusion

Performance was higher with the defensive than the offensive wheelchair, suggesting that the frequent finding that the higher performance of offensive as compared to defensive players is not related to the use of an offensive wheelchair.

A High-Intensity Warm-Up Increases Thermal Strain But Does Not Affect Repeated Sprint Performance in Athletes With a Cervical Spinal Cord Injury

PURPOSE

To compare the effects of typical competition versus high-intensity intermittent warm-up (WU) on thermoregulatory responses and repeated sprint performance during wheelchair rugby game play.

METHODS

An intermittent sprint protocol (ISP) simulating the demands of wheelchair rugby was performed by male wheelchair rugby players (7 with cervical spinal cord injury [SCI] and 8 without SCI) following 2 WU protocols. These included a typical competition WU (control) and a WU consisting of high-intensity efforts (INT). Core temperature (Tcore), thermal sensation, and thermal comfort were recorded. Wheelchair performance variables associated to power, speed, and fatigue were also calculated.

RESULTS

During the WU, Tcore was similar between conditions for both groups. During the ISP, a higher Tcore was found for SCI compared to NON-SCI (38.1 [0.3] vs 37.7 [0.3] °C: P = .036, d = 0.75), and the SCI group experienced a higher peak Tcore for INT compared with control (39.0 [0.4] vs 38.6 [0.6] °C; P = .004). Peak Tcore occurred later in the ISP for players with SCI (96 [5.8] vs 48 [2.7] min; P < .001). All players reported a higher thermal sensation and thermal comfort following INT (P < .001), with no differences between conditions throughout the ISP. No significant differences were found in wheelchair performance variables during the ISP between conditions (P ≥ .143).

CONCLUSIONS

The high-INT WU increased thermal strain in the SCI group during the ISP, potentially due to increased metabolic heat production and impaired thermoregulation, while not impacting on repeated sprint performance. It may be advisable to limit high-INT bouts during a WU in players with SCI to mitigate issues related to hyperthermia in subsequent performance.

Ice Slurry Ingestion Lowers Thermoregulatory Strain in Wheelchair Tennis Players During Repeated Sprint Intervals in the Heat

Purpose: To examine the efficacy of per-cooling via ice slurry ingestion (ICE) in wheelchair tennis players exercising in the heat. Method: Eight wheelchair tennis players undertook sprints (4 sets of 10 × 5 s over 40 min) in a hot environment (∼32 °C), interspersed by 3 boluses of 2.67 g·kg (6.8 g·kg total) ICE or drinking temperate water (control condition). Athletes performed an on-court test of repeated sprint ability (20 × 20 m) in temperate conditions immediately before and 20 minutes after the heat exposure, and time to complete each sprint as well as intermediate times were recorded. Gastrointestinal and weighted mean skin and forehead temperatures were collected throughout the heat exposure, as were thermal sensation, heart rate, and blood lactate concentration. Sweat rate was calculated from body mass changes and fluid/ice intakes. Results: Compared with the control condition, ICE resulted in a significantly lower gastrointestinal temperature (95% CI, 0.11–0.17 °C; P < .001), forehead temperature (0.58–1.06 °C; P < .001), thermal sensation (0.07–0.50 units; P = .017), and sweat rate (0.06–0.46 L·h−1; P = .017). Skin temperature, heart rate, and blood lactate concentration were not significantly different between conditions (P ≥ .598). There was no overall change preheating to postheating (P ≥ .114) or an effect of condition (P ≥ .251) on repeated sprint times. Conclusions: ICE is effective at lowering objective and subjective thermal strain when consumed between sets of repeated wheelchair sprints in the heat. However, ICE has no effect on on-court repeated 20-m sprint performance.

Wheelchair mobility performance of elite wheelchair tennis players during four field tests: Inter-trial reliability and construct validity

The purpose of the current study was to assess the inter-trial reliability and construct validity (talented juniors vs. international adult players) of four wheelchair tennis field tests using inertial measurement units (IMUs). Twenty-one elite wheelchair tennis players completed four tests, which evaluate the sprinting and manoeuvrability abilities in wheelchair tennis. During all tests 3 IMUs were attached to both wheels and the frame of the athlete's wheelchair. The IMUs enabled analysis of individual test dynamic characteristics, i.e. the linear/rotational velocity and acceleration data, as well as detected pushes. All tests showed high ICCs (0.95-0.99) for the inter-trial reliability for the IMU-based end times and also the construct validity was good, i.e. talented juniors could be discriminated from international adults. Also, velocities and accelerations during the tests could be consistently visualized, meaning that differences in test performance among participants could be designated. Within the experimental context, the field tests could be regarded as reliable and valid. With the use of IMUs it is possible to verify more detailed performance characteristics, visualize the test execution, as well as differentiate between a talented junior and international adult group and within individuals over time.

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.