Additional Clothing Increases Heat Load in Elite Female Rugby Sevens Players

Abstract

Purpose: To determine whether elite female rugby sevens players are exposed to core temperatures (Tc) during training in the heat that replicate the temperate match demands previously reported and to investigate whether additional clothing worn during a hot training session meaningfully increases the heat load experienced. Methods: A randomized parallel-group study design was employed, with all players completing the same approximately 70-minute training session (27.5°C–34.8°C wet bulb globe temperature) and wearing a standardized training ensemble (synthetic rugby shorts and training tee [control (CON); n = 8]) or additional clothing (standardized training ensemble plus compression garments and full tracksuit [additional clothing (AC); n = 6]). Groupwise differences in Tc, sweat rate, GPS-measured external locomotive output, rating of perceived exertion, and perceptual thermal load were compared. Results: Mean (P = .006, ) and peak (P < .001, ) Tc were higher in AC compared with CON during the training session. There were no differences in external load (F4,9 = 0.155, P = .956, Wilks Λ = 0.935, ) or sweat rate (P = .054, Cohen d = 1.09). A higher rating of perceived exertion (P = .016, Cohen d = 1.49) was observed in AC compared with CON. No exertional-heat-illness symptomology was reported in either group. Conclusions: Player Tc is similar between training performed in hot environments and match play in temperate conditions when involved for >6 minutes. Additional clothing is a viable and effective method to increase heat strain in female rugby sevens players without compromising training specificity or external locomotive capacity.

Heat Adaptation and Nutrition Practices: Athlete and Practitioner Knowledge and Use

“…These identified barriers require practice-facing solutions, such as the use of additional/thermal clothing and/or post-exercise thermal exposures [e.g. hot water immersion (HWI)] [22][23][24] . Indeed, a recent study showed that additional/thermal clothing, with or without post-exercise-HWI, were both shown to procure comparable performance improvements to those obtained from a 'classical' 10 day laboratory HA block in well-trained athletes 24 .…”

“…Perhaps reflective of these barriers and certainly indicative of technological advancement, ingestible telemetric temperature pills were commonly considered within the practice of practitioners in this study. Indeed, their use within elite sporting competition sees growth year on year 14,17,22,27,28 .…”

The relationship between physiological and performance variables during a hot/humid international rugby sevens tournament

“…Notably, some of these instances of T c ≥ 39.0°C occurred during warm‐ups, while four individuals reached a T c of > 39.0°C on more than one occasion. Previous investigations have demonstrated that playing minutes have a significant effect on individual post‐game T c during international rugby sevens tournaments in both male (Taylor et al, 2019) and female (Henderson et al, 2020b) athletes, even in modest environmental conditions. This relationship is also present in the current study ( p < 0.0001, η 2 p = 0.29), with game time being > 6 min on 16/17 occasions when post‐game T c was > 39.0°C.…”

“…There has been limited investigations into how HA would best fit into an elite rugby sevens environment due to the competing influences of other training demands, travel and tournaments (Casadio, Kilding, Cotter, & Laursen, 2017). With traditional HA recommendations being largely unfeasible in an elite rugby sevens setting, practical solutions, such as wearing additional clothing during training have been shown to provide an increased thermal stimulus, without impacting external running load during training sessions (Henderson et al, 2020b). In turn, utilising common pre-and per-cooling strategies such as the ingestion of ice slushy (Beaven et al, 2018;Brade, Dawson, & Wallman, 2014), application of icetowels (Duffield, Steinbacher, & Fairchild, 2009;Minett, Duffield, Marino, & Portus, 2012) and ice vests pre and during warm up (Taylor et al, 2019) has been suggested as best practice in team sports (Aldous et al, 2018;Tyler, Sunderland, & Cheung, 2015).…”

Responses to a 5-Day Sport-Specific Heat Acclimatization Camp in Elite Female Rugby Sevens Athletes

“…18 The e-Celsius TM system has also been used previously within elite rugby sevens matches 14,16 and training. 19,20 In the case of technological error or the capsule being passed prior to data collection [this occurred for 6 of the 38 attempted measures (19 participants x 2 measures each)], resting Tc data were not able to be collected. Cardiovascular fitness changes were indirectly monitored by tracking changes in HRex to a 4minute submaximal continuous run at 12 km•h -1 and recording the final 30 seconds mean value.…”