Katharine E. Griggs

Thermoregulation During Intermittent Exercise in Athletes With a Spinal-Cord Injury

PURPOSE Individuals with a spinal-cord injury have impaired thermoregulatory control due to a loss of sudomotor and vasomotor effectors below the lesion level. Thus, individuals with high-level lesions (tetraplegia) possess greater thermoregulatory impairment than individuals with lower-level lesions (paraplegia). Previous research has not reflected the intermittent nature and modality of wheelchair court sports or replicated typical environmental temperatures. Hence, the purpose of this study was to investigate the thermoregulatory responses of athletes with tetraplegia and paraplegia during an intermittent-sprint protocol (ISP) and recovery in cool conditions. METHODS Sixteen wheelchair athletes, 8 with tetraplegia (TP, body mass 65.2±4.4 kg) and 8 with paraplegia (body mass 68.1±12.3 kg), completed a 60-min ISP in 20.6°C±0.1°C, 39.6%±0.8% relative humidity on a wheelchair ergometer, followed by 15 min of passive recovery. Core temperature (Tcore) and mean (Tsk) and individual skin temperatures were measured throughout. RESULTS Similar external work (P=.70, ES=0.20) yet a greater Tcore (P<.05, ES=2.27) and Tsk (P<.05, ES=1.50) response was demonstrated by TP during the ISP. CONCLUSIONS Despite similar external work, a marked increase in Tcore in TP during exercise and recovery signifies that thermoregulatory differences between the groups were predominantly due to differences in heat loss. Further increases in thermal strain were not prevented by the active and passive recovery between maximal-effort bouts of the ISP, as Tcore continually increased throughout the protocol in TP.

Effects of cooling before and during simulated match play on thermoregulatory responses of athletes with tetraplegia

OBJECTIVES Athletes with high level spinal cord injuries (tetraplegia) are under greater thermal strain during exercise than the able-bodied. The purpose of this study was to investigate the effectiveness of pre-cooling using an ice vest and the combination of pre-cooling and cooling during play using water sprays in athletes with tetraplegia. DESIGN Counter-balanced, cross-over design. METHODS Eight wheelchair rugby players with tetraplegia completed a 60min intermittent sprint protocol (ISP) on a wheelchair ergometer in 20.2°C±0.2°C and 33.0%±3.1% relative humidity. The ISP was conducted on three occasions; no cooling (NC), pre-cooling with an ice vest (P) and pre-cooling with an ice vest and water sprays between quarters (PW). Gastrointestinal (Tgi) temperature, mean skin temperature (Tsk) and perceptual responses were measured throughout. RESULTS At the end of pre-cooling, the change in Tgi was not significantly different between conditions (P>0.05) but the change in Tsk was significantly greater in P and PW compared to NC (P<0.001). The change in Tgi over the ISP was significantly lower in PW and P compared to NC (P<0.05), whilst the change in Tsk was lower in PW compared to P and NC (P<0.05). Cooling had no effect on performance or perceptual responses (P>0.05). CONCLUSIONS Water spraying between quarters combined with pre-cooling using an ice vest lowers thermal strain to a greater degree than pre-cooling only in athletes with tetraplegia, but has no effect on simulated wheelchair rugby performance or perceptual responses.

Thermoregulatory Responses during Competitive Wheelchair Rugby Match Play

The purpose of this study was to determine whether a players physical impairment or activity profile was related to the amount of thermal strain experienced during wheelchair rugby match play. 17 elite wheelchair rugby players played a competitive match, whilst activity profiles, measures of core and skin temperature, heart rate and perceptual responses were taken. Players were divided into 2 groups depending on their physical impairment: players with a cervical spinal cord injury, (n=10) or non-spinal related physical impairment (n=7). Total distance was lower (4 842±324 vs. 5 541±316 m, p<0.01, ES=2.2) and mean speed slower (1.13±0.11 vs. 1.27±0.11 m∙s-1, p<0.03, ES=1.3) in players with a spinal cord injury. Yet, the change in core temperature (1.6±0.4 vs. 0.7±0.3°C, p<0.01, ES=2.5) was significantly greater in players with a spinal cord injury. In conclusion, players with a spinal cord injury were under greater thermal strain during wheelchair rugby match play, as a result of their reduced heat loss capacity, due to their physical impairment and not because of their activity profile.

Supporting Paralympic wheelchair sport performance through technological, physiological and environmental considerations

This is an Accepted Manuscript of an article published by Taylor & Francis in Annals of Human Biology on 25 Sep 2016, available online: http://www.tandfonline.com/10.1080/03014460.2016.1234644.