Wheelchair sport: pushing from Atlanta to Rio, the sports science journey

In order to develop and implement safe and effective training programmes for a wheelchair athlete an understanding of the physical impairment is essential. This article will focus on the wheelchair athlete to describe how the training prescription for the non-disabled may be challenged in terms of its use for athletes with a spinal cord injury (SCI); describe the approach taken to optimise wheelchair set-up and finally describe how a multi-disciplinary sports science team prepares athletes for competition in the heat

Mixed active and passive, heart rate-controlled heat acclimation is effective for Paralympic and able-bodied triathletes

Purpose To explore the effectiveness of mixed, active and passive heat acclimation (HA), controlling the relative intensity of exercise by heart rate (HR) in paratriathletes (PARA) and determine adaptation differences to able-bodied (AB) triathletes.Methods Seven elite paratriathletes and thirteen AB triathletes undertook an 8-d HA intervention consisting of five HR-controlled sessions and three passive heat exposures (35oC, 63% relative humidity). On the first and last day of HA, heat stress tests were conducted whereby thermoregulatory changes were recorded during at a fixed, submaximal workload. The AB group undertook 20 km cycling time trials pre- and post-HA with performance compared to an AB, non-acclimated control group.Results During the heat stress test, HA lowered core temperature (PARA: 0.27 ± 0.32oC; AB: 0.28 ± 0.34oC), blood lactate concentration (PARA: 0.23 ± 0.15 mmol∙l-1; AB: 0.38 ± 0.31 mmol∙l-1) with concomitant plasma volume expansion (PARA: 12.7 ± 10.6; AB: 6.2 ± 7.7%) (p≤0.047). In the AB group, a lower skin temperature (0.19 ± 0.44oC) and HR (5 ± 6 bpm) with a greater sweat rate (0.17 ± 0.25 l∙h-1) was evident post-HA (p≤0.045) but this was not present for the PARA group (p≥0.177). The AB group improved their performance by an extent greater than the smallest worthwhile change based on the normal variation present with no HA (4.5 vs. 3.7%).Conclusions Paratriathletes are capable of displaying partial HA, albeit not to same extent as AB triathletes. The HA protocol was effective at stimulating thermoregulatory adaptations with performance changes noted in AB triathletes.</div

Current perspectives on profiling and enhancing wheelchair court-sport performance

Despite the growing interest in Paralympic sport, the evidence-base for supporting elite wheelchair sport performance remains in its infancy when compared to able-bodied (AB) sport. Subsequently, current practice is often based on theory adapted from AB guidelines, with a heavy reliance on anecdotal evidence and practitioner experience. Many principles in training prescription and performance monitoring with wheelchair athletes are directly transferable from AB practice, including the periodisation and tapering of athlete loads around competition. Yet, a consideration for the physiological consequences of an athlete’s impairment and the interface between athlete and their equipment are vital when targeting interventions to optimise in-competition performance. Researchers and practitioners are faced with the challenge of identifying and implementing reliable protocols that detect small but meaningful changes in impairment-specific physical capacities and on-court performance. Technologies to profile both linear and rotational on-court performance are an essential component of sports science support in order to understand sport-specific movement profiles and prescribe training intensities. In addition, an individualised approach to the prescription of athlete training and optimisation of the ‘wheelchair/user interface’ is required, accounting for an athlete’s anthropometrics, sports classification and positional role on court. As well as enhancing physical capacities, interventions must also focus on the integration of the athlete and their equipment as well as techniques for limiting environmental influence on performance. Taken together, the optimisation of wheelchair sport performance requires a multi-disciplinary approach based on the individual requirements of each athlete

Improvements in cycling but not handcycling 10 km time trial performance in habitual caffeine users

Caffeine supplementation during whole-/lower-body exercise is well-researched, yet evidence of its effect during upper-body exercise is equivocal. The current study explored the effects of caffeine on cycling/handcycling 10 km time trial (TT) performance in habitual caffeine users. Eleven recreationally trained males (mean (SD) age 24 (4) years, body mass 85.1 (14.6) kg, cycling/handcycling peak oxygen uptake (V peak) 42.9 (7.3)/27.6 (5.1) mL·kg·min−1, 160 (168) mg/day caffeine consumption) completed two maximal incremental tests and two familiarization sessions. During four subsequent visits, participants cycled/handcycled for 30 min at 65% mode-specific V peak (preload) followed by a 10 km TT following the ingestion of 4 mg·kg−1 caffeine (CAF) or placebo (PLA). Caffeine significantly improved cycling (2.0 (2.0)%; 16:35 vs. 16:56 min; p = 0.033) but not handcycling (1.8 (3.0)%; 24:10 vs. 24:36 min; p = 0.153) TT performance compared to PLA. The improvement during cycling can be attributed to the increased power output during the first and last 2 km during CAF. Higher blood lactate concentration (Bla) was reported during CAF compared to PLA (p < 0.007) and was evident 5 min post-TT during cycling (11.2 ± 2.6 and 8.8 ± 3.2 mmol/L; p = 0.001) and handcycling (10.6 ± 2.5 and 9.2 ± 2.9 mmol/L; p = 0.006). Lower overall ratings of perceived exertion (RPE) were seen following CAF during the preload (p < 0.05) but not post-TT. Lower peripheral RPE were reported at 20 min during cycling and at 30 min during handcycling, and lower central RPE was seen at 30 min during cycling (p < 0.05). Caffeine improved cycling but not handcycling TT performance. The lack of improvement during handcycling may be due to the smaller active muscle mass, elevated (Bla) and/or participants’ training status

Exercise intensity and its impact on relationships between salivary immunoglobulin A, saliva flow rate and plasma cortisol concentration

Introduction Salivary secretory immunoglobulin A (sIgA), saliva flow rate and plasma cortisol concentrations have been shown to be influenced by exercise, particularly the intensity exercise is performed at, and circadian variation. The autonomic nervous system partly regulates salivary secretion, but it is not yet known whether cortisol also explains some variation in salivary parameters. Methods Twelve moderately trained male individuals (V̇ O2peak legs: 46.2±6.8 mL·kg−1·min−1) performed three 45-min constant load exercise trials in the morning: arm cranking exercise at 60%V̇ O2peak arms; moderate cycling at 60%V̇ O2peak legs; and easy cycling at 60%V̇ O2peak arms. Timed saliva samples and blood samples for plasma cortisol concentration determination were obtained before, post, 2 h post, and 4 h post-exercise. Saliva was collected in an additional resting trial at the same time points. Results At each time point for each exercise trial, negative correlations between cortisol and saliva flow rate (explaining 25±17% of the variance, R2=0.002–0.46) and positive correlations between cortisol and sIgA concentration (explaining 8±8% of the variance R2=0.002–0.24) were found. Saliva flow rate increased over time, whereas sIgA concentration and cortisol decreased over time for all trials (P<0.05), there was no effect of time for sIgA secretion rate (P=0.16). Conclusion These results show a relationship between cortisol and saliva flow rate, which directly impacts on the concentration of salivary analytes. This study further confirms circadian variations in salivary parameters which must be acknowledged when standardising salivary data collection

Expert users’ perceptions of racing wheelchair design and set up: The knowns, unknowns and next steps

This paper demonstrates how a qualitative methodology can be used to gain novel insights into the demands of wheelchair racing and the impact of particular racing chair configurations on optimal sport performance via engagement with expert users (wheelchair racers, coaches and manufacturers). We specifically explore how expert users understand how wheels, tires and bearings impact upon sport performance and how they engage, implement or reject evidence-based research pertaining to these components. We identify areas where participants perceive there to be an immediate need for more research especially pertaining to the ability to make individualized recommendations for athletes. The findings from this project speak to the value of a qualitative research design for capturing the embodied knowledge of expert users and also make suggestions for ‘next step’ projects pertaining to wheels, tires and bearings drawn directly from the comments of participants

Spinal cord injury: known and possible influences on the immune response to exercise

A spinal cord injury (SCI) can increase the risk of infection by impacting on many aspects of immune function; one particularly well-documented observation is a reduction in lymphocyte numbers. The vast majority of lymphoid cells express adrenergic receptors. Therefore, autonomic function loss and concomitant alterations in resting and post-exercise catecholamine concentrations, particularly so in individuals with a tetraplegia, may impact directly on immune cells and depress immunity. Other factors are further likely to contribute, examples including altered muscular, endocrine and cardiovascular function following SCI. However, some alterations, such as increases in natural killer cell cytotoxicity following exercise in those with a tetraplegia, are unrelated to the catecholamine response. Likewise, mucosal immunity in individuals with a tetraplegia appears to be similarly influenced by exercise as in the able-bodied population. Indeed, rehabilitation therapy and exercise can increase some measures of immunity and autonomic function in those with an SCI. It is therefore possible that compensatory mechanisms offset disability-related detriments. This may be by way of sympathetic reflex activity, receptor hypersensitivity, or parasympathetic and neuroendocrine adjustments. Future work needs to explore these mechanisms further to clarify the implications of an SCI on the immune response to exercise and susceptibility to infection. In this article, we review the impacts of an SCI on immune, and specifically, exercise immune function. The relevant anatomical and physiological foundations of the immune system are first briefly laid out in order to understand the potential impacts of neural and neuroendocrine dysfunction on the immune system. With the limited number of human studies available, we have then aimed specifically to gather all relevant existing literature on exercise immunology in individuals with an SCI in patient, recreationally active and athlete populations. We believe that an understanding of the impacts of exercise can provide a tool to help maintain or improve health in individuals with an SCI

A multi-factorial assessment of elite paratriathletes’ response to two weeks of intensified training

Purpose: In able-bodied athletes, several hormonal, immunological and psychological parameters are commonly assessed in response to intensified training due to their potential relationship to acute fatigue and training/non-training stress. This has yet to be studied in Paralympic athletes. Methods: Ten elite paratriathletes were studied for five weeks around a 14-day overseas training camp whereby training load was 137% of pre-camp levels. Athletes provided: six saliva samples (one pre-camp, four during camp, one post-camp) for cortisol, testosterone and secretory immunoglobulin A; weekly psychological questionnaires (POMS and RESTQ-S); daily resting heart rate and subjective wellness measures including sleep quality and quantity. Results: There was no significant change in salivary cortisol, testosterone, cortisol:testosterone ratio or secretory immunoglobulin A during intensified training (p≥0.090). Likewise, there was no meaningful change in resting heart rate or subjective wellness measures (p≥0.079). Subjective sleep quality and quantity increased during intensified training (p≤0.003). There was no significant effect on any POMS subscale other than lower anger (p=0.049) whilst there was greater general recovery and lower sport and general stress from RESTQ-S (p≤0.015). Conclusions: There was little to no change in parameters commonly associated with the fatigued state which may relate to the training camp setting minimising external life stresses and the careful management of training loads from coaches. This is the first evidence of such responses in Paralympic athletes

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

Understanding the impact of trunk and arm impairment on wheelchair rugby performance during competition

Purpose: To determine the effect of trunk and arm impairment on physical and technical performance during wheelchair rugby (WR) competition. Methods: Thirty-one highly trained WR players grouped according to their trunk (no trunk [NT]; some trunk [T] function) and arm impairment (poor [PAF]; moderate [MAF]; good [GAF] arm function) participated in 5 WR matches. Player’s physical (wheelchair mobility) and technical (ball handling) activities were analysed using an indoor tracking system and video analysis respectively. Results: Trunk impairment explained some of the variance in physical (10.6–23.5%) and technical (16.2–33.0%) performance. T covered more distance, had more possession, scored more goals, received and made more passes, yet spent less time at low speeds and performed fewer inbounds than NT (≤ 0.05). Arm impairment explained some of the variance in all physical (16.7–47.0%) and the majority of technical (13.1–53.3%) performance measures. MAF and GAF covered more distance, reached higher peak speeds, spent more time in higher speed zones, scored more goals, had more possession, received and made more passes, with a higher percentage of one-handed and long passes than PAF. GAF also received more passes and made a higher percentage of one-handed passes and defensive blocks than MAF (P ≤ 0.05). Conclusions: Arm impairment impacts a greater number of physical and technical measures of performance specific to WR than trunk impairment during competition. Having active finger function (GAF) yielded no further improvements in physical performance but positively influenced a small number of technical skill