Limiting the Rise in Core Temperature During a Rugby Sevens Warm-Up With an Ice Vest

Purpose: To determine how a cooling vest worn during a warm-up could influence selected performance (countermovement jump [CMJ]), physical (global positioning system [GPS] metrics), and psychophysiological (body temperature and perceptual) variables. Methods: In a randomized, crossover design, 12 elite male World Rugby Sevens Series athletes completed an outdoor (wet bulb globe temperature 23–27°C) match-specific externally valid 30-min warm-up wearing a phase-change cooling vest (VEST) and without (CONTROL), on separate occasions 7 d apart. CMJ was assessed before and after the warm-up, with GPS indices and heart rate monitored during the warm-ups, while core temperature (Tc; ingestible telemetric pill; n = 6) was recorded throughout the experimental period. Measures of thermal sensation (TS) and thermal comfort (TC) was obtained pre-warm-up and post-warm-up, with rating of perceived exertion (RPE) taken post-warm-ups. Results: Athletes in VEST had a lower ΔTc (mean [SD]: VEST = 1.3°C [0.1°C]; CONTROL = 2.0°C [0.2°C]) from pre-warm-up to post-warm-up (effect size; ±90% confidence limit: −1.54; ±0.62) and Tc peak (mean [SD]: VEST = 37.8°C [0.3°C]; CONTROL = 38.5°C [0.3°C]) at the end of the warm-up (−1.59; ±0.64) compared with CONTROL. Athletes in VEST demonstrated a decrease in ΔTS (−1.59; ±0.72) and ΔTC (−1.63; ±0.73) pre-warm-up to post-warm-up, with a lower RPE post-warm-up (−1.01; ±0.46) than CONTROL. Changes in CMJ and GPS indices were trivial between conditions (effect size < 0.2). Conclusions: Wearing the vest prior to and during a warm-up can elicit favorable alterations in physiological (Tc) and perceptual (TS, TC, and RPE) warm-up responses, without compromising the utilized warm-up characteristics or physical-performance measures.

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Additional Clothing Increases Heat Load in Elite Female Rugby Sevens Players

International Journal of Sports Physiology and Performance ◽

10.1123/ijspp.2020-0620 ◽

2020 ◽

pp. 1-8

Author(s):

Mitchell J. Henderson ◽

Bryna C.R. Chrismas ◽

Christopher J. Stevens ◽

Andrew Novak ◽

Job Fransen ◽

...

Keyword(s):

Heat Load ◽

Perceived Exertion ◽

Sweat Rate ◽

Training Session ◽

Rating Of Perceived Exertion ◽

Compression Garments ◽

Wet Bulb Globe Temperature ◽

Parallel Group ◽

Globe Temperature ◽

Hot Environments

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.

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Heat Added to Repeated-Sprint Training in Hypoxia Does Not Affect Cycling Performance

International Journal of Sports Physiology and Performance ◽

10.1123/ijspp.2020-0676 ◽

2021 ◽

pp. 1-9

Author(s):

Myles C. Dennis ◽

Paul S.R. Goods ◽

Martyn J. Binnie ◽

Olivier Girard ◽

Karen E. Wallman ◽

...

Keyword(s):

Oxygen Saturation ◽

Core Temperature ◽

Perceived Exertion ◽

Thermal Sensation ◽

Rating Of Perceived Exertion ◽

Sprint Training ◽

Active Recovery ◽

Repeated Sprint ◽

Air Temperatures ◽

Desirable Outcome

Purpose: This study aimed to assess the influence of graded air temperatures during repeated-sprint training in hypoxia (RSH) on performance and physiological responses. Methods: Ten well-trained athletes completed one familiarization and 4 experimental sessions at a simulated altitude of 3000 m (0.144 FIO2) above sea level. Air temperatures utilized across the 4 experimental sessions were 20°C, 25°C, 30°C, and 35°C (all 50% relative humidity). The participants performed 3 sets of 5 × 10 seconds “all-out” cycle sprints, with 20 seconds of active recovery between sprints and 5 minutes of active recovery between sets (recovery intensity = 120 W). Core temperature, skin temperature, pulse oxygen saturation, heart rate, rating of perceived exertion, and thermal sensation were collected. Results: There were no differences between conditions for peak power, mean power, and total work in each set (P > .05). There were no condition × time interaction effects for any variables tested. The peak core temperature was highest at 30°C (38.06°C [0.31°C]). Overall, the pulse oxygen saturation was higher at 35°C than at 20°C (P < .001; d < 0.8), 25°C (P < .001; d = 1.12 ± 0.54, large), and 30°C (P < .001; d = 0.84 ± 0.53, large). Conclusion: Manipulating air temperature between 20°C and 35°C had no effect on performance or core temperature during a typical RSH session. However, the pulse oxygen saturation was preserved at 35°C, which may not be a desirable outcome for RSH interventions. The application of increased levels of ambient heat may require a different approach if augmenting the RSH stimulus is the desired outcome.

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Core Temperature Responses in Elite Cricket Players during Australian Summer Conditions

Sports ◽

10.3390/sports6040164 ◽

2018 ◽

Vol 6 (4) ◽

pp. 164

Author(s):

Sharon Stay ◽

Michelle Cort ◽

David Ward ◽

Alex Kountouris ◽

John Orchard ◽

...

Keyword(s):

Core Temperature ◽

Air Temperature ◽

Perceived Exertion ◽

Wet Bulb Globe Temperature ◽

Exertional Heat Illness ◽

Increased Risk ◽

Globe Temperature ◽

Temperature Responses ◽

Breaks In Play ◽

Australian Summer

This study aimed to observe core temperature responses in elite cricket players under match conditions during the summer in Australia. Thirty-eight Australian male cricketers ingested capsule temperature sensors during six four-day first-class matches between February 2016 and March 2017. Core temperature (Tc) was recorded during breaks in play. Batters showed an increase in Tc related to time spent batting of approximately 1 °C per two hours of play (p < 0.001). Increases in rate of perceived exertion (RPE) in batters correlated with smaller elevations in Tc (0.2 °C per one unit of elevation in RPE) (p < 0.001). Significant, but clinically trivial, increases in Tc of batters were found related to the day of play, wet bulb globe temperature (WBGT), air temperature, and humidity. A trivial increase in Tc (p < 0.001) was associated with time in the field and RPE when fielding. There was no association between Tc and WBGT, air temperature, humidity, or day of play in fielders. This study demonstrates that batters have greater rises in Tc than other cricket participants, and may have an increased risk of exertional heat illness, despite exposure to similar environmental conditions.

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Limiting Rise in Heat Load With an Ice Vest During Elite Female Rugby Sevens Warm-Ups

International Journal of Sports Physiology and Performance ◽

10.1123/ijspp.2020-0833 ◽

2021 ◽

pp. 1-8

Author(s):

Mitchell J. Henderson ◽

Bryna C.R. Chrismas ◽

Christopher J. Stevens ◽

Job Fransen ◽

Aaron J. Coutts ◽

...

Keyword(s):

Confidence Interval ◽

Phase Change ◽

Core Temperature ◽

Temperature Rise ◽

Training Session ◽

Warm Up ◽

Wet Bulb Globe Temperature ◽

Globe Temperature ◽

Simulated Match ◽

Cool Conditions

Purpose: To determine the effect of wearing a phase-change cooling vest in elite female rugby sevens athletes during (1) a simulated match-day warm-up in hot conditions prior to a training session and (2) a prematch warm-up during a tournament in cool conditions. Methods: This study consisted of 2 randomized independent group designs (separated by 16 d) where athletes completed the same 23- to 25-minute match-day warm-up (1) in hot conditions (range = 28.0°C to 35.1°C wet bulb globe temperature [WBGT]) prior to training and (2) in cool conditions (range = 18.8°C to 20.1°C WBGT) prior to a World Rugby Women’s Sevens Series match. In both conditions, athletes were randomly assigned to wearing either (1) the standardized training/playing ensemble (synthetic rugby shorts and training tee/jersey) or (2) the standardized training/playing ensemble plus a commercial phase-change athletic cooling vest. Group-wise differences in core temperature rise from baseline, global positioning system–measured external locomotive output, and perceptual thermal load were compared. Results: Core temperature rise during a match warm-up was lower in the hot condition only (−0.65°C [95% confidence interval = −1.22°C to −0.08°C], [95% confidence interval = .00 to .51], P = .028). No differences in various external-load variables were observed. Conclusions: Phase-change cooling vests can be worn by athletes prior to, and during, a prematch warm-up in hot conditions to limit excess core temperature rise without adverse effects on thermal perceptions or external locomotion output.

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Effects of Adding Small Combat Games to Regular Taekwondo Training on Physiological and Performance Outcomes in Male Young Athletes

Frontiers in Physiology ◽

10.3389/fphys.2021.646666 ◽

2021 ◽

Vol 12 ◽

Author(s):

Ibrahim Ouergui ◽

Emerson Franchini ◽

Hamdi Messaoudi ◽

Hamdi Chtourou ◽

Anissa Bouassida ◽

...

Keyword(s):

Perceived Exertion ◽

Lactate Concentration ◽

Blood Lactate Concentration ◽

Random Order ◽

Performance Outcomes ◽

Rating Of Perceived Exertion ◽

Control Group ◽

Metabolic Demand ◽

Before And After ◽

Post Hoc

This study investigated the effect of area sizes (4 × 4, 6 × 6, and 8 × 8 m) and effort-pause ratios (free combat vs. 1:2) variation on the physiological and perceptive responses during taekwondo combats (Study 1). In a second study, the effects on physical performance of 8 weeks of small combat-based training added to regular taekwondo training were investigated (Study 2). In random order, 32 male taekwondo athletes performed six (i.e., two effort-to-pause ratios × three area sizes conditions) different 2-min taekwondo combats (Study 1). Thereafter (Study 2), they were randomly assigned to three experimental groups (4 × 4, 6 × 6, and 8 × 8 m) and an active control group (CG). Regarding Study 1, blood lactate concentration [La] before and after each combat, mean heart rate (HRmean) during each combat, and rating of perceived exertion (CR-10) immediately after each combat were assessed. Regarding Study 2, progressive specific taekwondo (PSTT) to estimate maximum oxygen consumption (VO2max), taekwondo-specific agility, and countermovement jump (CMJ) tests were administered before and after 8 weeks of training. Study 1 results showed that 4 × 4 m elicited lower HRmean values compared with 6 × 6 m (d = −0.42 [small], p = 0.030) and free combat induced higher values compared with the 1:2 ratio (d = 1.71 [large], p < 0.001). For [La]post, 4 × 4 m area size induced higher values than 6 × 6 m (d = 0.99 [moderate], p < 0.001) and 8 × 8 m (d = 0.89 [moderate], p < 0.001) and free combat induced higher values than 1:2 ratio (d = 0.69 [moderate], p < 0.001). Higher CR-10 scores were registered after free combat compared with 1:2 ratio (d = 0.44 [small], p = 0.007). For Study 2, VO2max increased after training [F(1, 56) =30.532, p < 0.001; post-hoc: d = 1.27 [large], p < 0.001] with higher values for 4 × 4 m compared with CG (d = 1.15 [moderate], p = 0.009). Agility performance improved after training [F(1, 56) = 4.419, p = 0.04; post-hoc: d = −0.46 [small], p = 0.04] and 4 × 4 m induced lower values in comparison with 6 × 6 m (d = −1.56 [large], p = 0.001) and CG (d = −0.77 [moderate], p = 0.049). No training type influenced CMJ performance. Smaller area size elicited contrasting results in terms of metabolic demand compared with larger sizes (i.e., lower HRmean but higher [La] and CR-10), whereas free combat induced variables' consistently higher values compared with imposed 1:2 ratio (Study 1). Taekwondo training is effective to improve VO2max and agility (Study 2), but small combat training modality should be investigated further.

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Core temperature up to 41.5ºC during the UCI Road Cycling World Championships in the heat

British Journal of Sports Medicine ◽

10.1136/bjsports-2018-099881 ◽

2018 ◽

Vol 53 (7) ◽

pp. 426-429 ◽

Cited By ~ 21

Author(s):

Sebastien Racinais ◽

Sebastien Moussay ◽

David Nichols ◽

Gavin Travers ◽

Taoufik Belfekih ◽

...

Keyword(s):

Heart Rate ◽

Core Temperature ◽

Power Output ◽

Temperature Response ◽

Time Trial ◽

Ambient Conditions ◽

Wet Bulb Globe Temperature ◽

Road Cycling ◽

Road Race ◽

Globe Temperature

ObjectiveTo characterise the core temperature response and power output profile of elite male and female cyclists during the 2016 UCI Road World Championships. This may contribute to formulating environmental heat stress policies.MethodsCore temperature was recorded via an ingestible capsule in 10, 15 and 15 cyclists during the team time trial (TTT), individual time trial (ITT) and road race (RR), respectively. Power output and heart rate were extracted from individual cycling computers. Ambient conditions in direct sunlight were hot (37°C±3°C) but dry (25%±16% relative humidity), corresponding to a wet-bulb globe temperature of 27°C±2°C.ResultsCore temperature increased during all races (p<0.001), reaching higher peak values in TTT (39.8°C±0.9°C) and ITT (39.8°C±0.4°C), relative to RR (39.2°C±0.4°C, p<0.001). The highest temperature recorded was 41.5°C (TTT). Power output was significantly higher during TTT (4.7±0.3 W/kg) and ITT (4.9±0.5 W/kg) than RR (2.7±0.4 W/kg, p<0.001). Heart rate increased during the TTs (p<0.001) while power output decreased (p<0.001).Conclusion85% of the cyclists participating in the study (ie, 34 of 40) reached a core temperature of at least 39°C with 25% (ie, 10 of 40) exceeding 40°C. Higher core temperatures were reached during the time trials than the RR.

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Practical Torso Cooling During Soccer-Specific Exercise in the Heat

Journal of Athletic Training ◽

10.4085/1062-6050-417-17 ◽

2018 ◽

Vol 53 (11) ◽

pp. 1089-1097 ◽

Cited By ~ 1

Author(s):

Kirstie Parris ◽

Christopher J. Tyler

Keyword(s):

Perceived Exertion ◽

Intermittent Exercise ◽

Thermal Sensation ◽

Sprint Performance ◽

Rating Of Perceived Exertion ◽

Sprint Speed ◽

Minute Period ◽

Improve Exercise Performance ◽

C 50 ◽

Cool Conditions

Context Precooling and midevent cooling of the torso using cooling vests can improve exercise performance in the heat with or without physiological changes; however, the effects of such cooling during intermittent exercise in the heat are unknown. Objective To investigate the effects of torso cooling during intermittent exercise in the heat (35°C, 50% relative humdity) on sprint performance and the physiological and perceptual responses to the exercise. Design Crossover study. Setting Walk-in environmental chamber. Patients or Other Participants Ten non–heat-acclimated, male soccer players (age = 25 ± 2 years, height = 1.77 ± 0.06 m, mass = 72.9 ± 7.6 kg). Intervention(s) Two 90-minute bouts of soccer-specific intermittent running in the heat: 1 trial with a cooling vest worn during the exercise and 1 trial without a cooling vest. Each trial comprised two 45-minute periods separated by approximately 15 minutes of seated rest in cool conditions (approximately 23°C, 50% relative humdity). Main Outcome Measure(s) Peak sprint speed, rectal temperature (Tr), mean-weighted skin temperature (Tsk), heart rate (HR), rating of perceived exertion (RPE), and thermal sensation (TS) were measured every 5 minutes. Results Peak sprint performance was largely unaffected by the cooling vest. The Tr, Tsk, HR, RPE, and TS were unaffected in the cooling-vest trial during the first 45 minutes, but Tr rose at a slower rate in the cooling-vest trial (0.026°C.min–1 ± 0.008°C.min–1) than in the no-vest trial (0.032°C.min–1 ± 0.009°C.min–1). During the second 45-minute period, Tr, Tr rate of rise, Tsk, RPE, and TS were lower in the cooling-vest trial (Hedges g range, 0.55–0.84), but mean HR was unaffected. Conclusions Wearing a cooling vest during soccer-specific intermittent running in the heat reduced physiological and perceptual strain but did not increase peak sprint speed.

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Consecutive Days of Prolonged Tennis Match Play: Performance, Physical, and Perceptual Responses in Trained Players

International Journal of Sports Physiology and Performance ◽

10.1123/ijspp.2014-0329 ◽

2015 ◽

Vol 10 (7) ◽

pp. 913-920 ◽

Cited By ~ 31

Author(s):

Danielle T. Gescheit ◽

Stuart J. Cormack ◽

Machar Reid ◽

Rob Duffield

Keyword(s):

Effect Size ◽

Perceived Exertion ◽

Voluntary Contraction ◽

Rating Of Perceived Exertion ◽

Perceptual Training ◽

Match Play ◽

Tennis Players ◽

Playing Time ◽

Distress Scale ◽

Tennis Match

Purpose:To determine how consecutive days of prolonged tennis match play affect performance, physiological, and perceptual responses.Methods:Seven well-trained male tennis players completed 4-h tennis matches on 4 consecutive days. Pre- and postmatch measures involved tennis-specific (serve speed and accuracy), physical (20-m sprint, countermovement jump [CMJ], shoulder-rotation maximal voluntary contraction, isometric midthigh pull), perceptual (Training Distress Scale, soreness), and physiological (creatine kinase [CK]) responses. Activity profile was assessed by heart rate, 3D load (accumulated accelerations measured by triaxial accelerometers), and rating of perceived exertion (RPE). Statistical analysis compared within- and between-days values. Changes (± 90% confidence interval [CI]) ≥75% likely to exceed the smallest important effect size (0.2) were considered practically important.Results:3D load reduced on days 2 to 4 (mean effect size ± 90% CI –1.46 ± 0.40) and effective playing time reduced on days 3 to 4 (–0.37 ± 0.51) compared with day 1. RPE did not differ and total points played only declined on day 3 (–0.38 ± 1.02). Postmatch 20-m sprint (0.79 ± 0.77) and prematch CMJ (–0.43 ± 0.27) performance declined on days 2 to 4 compared with prematch day 1. Although serve velocity was maintained, compromised postmatch serve accuracy was evident compared with prematch day 1 (0.52 ± 0.58). CK increased each day, as did ratings of muscle soreness and fatigue.Conclusions:Players reduced external physical loads, through declines in movement, over 4 consecutive days of prolonged competitive tennis. This may be affected by tactical changes and pacing strategies. Alongside this, impairments in sprinting and jumping ability, perceptual and biochemical markers of muscle damage, and reduced mood states may be a function of neuromuscular and perceptual fatigue.

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