phenotype. Despite this, early adaptations such as lowered core temperature ( T c ) and exercise heart rate (HRex) can be obtained in as little as a few days. 5 While prolonged HA protocols are understood to be the most effective in achieving the desired outcomes, team sport practitioners seeking heat
Search Results
Responses to a 5-Day Sport-Specific Heat Acclimatization Camp in Elite Female Rugby Sevens Athletes
Mitchell J. Henderson, Bryna C.R. Chrismas, Job Fransen, Aaron J. Coutts, and Lee Taylor
Core Temperature and Sweating in Men and Women During a 15-km Race in Cool Conditions
Coen C.W.G. Bongers, Dominique S.M. ten Haaf, Nicholas Ravanelli, Thijs M.H. Eijsvogels, and Maria T.E. Hopman
/fatness-related factors . J Appl Physiol . 2015 ; 119 ( 9 ): 982 – 989 . doi:10.1152/japplphysiol.00281.2015 26316511 8. Gagnon D , Dorman LE , Jay O , Hardcastle S , Kenny GP . Core temperature differences between males and females during intermittent exercise: physical considerations . Eur J Appl
Heat Added to Repeated-Sprint Training in Hypoxia Does Not Affect Cycling Performance
Myles C. Dennis, Paul S.R. Goods, Martyn J. Binnie, Olivier Girard, Karen E. Wallman, Brian T. Dawson, and Peter Peeling
30°C to 35°C can increase acute repeated-sprint performance without deleterious heat stress. 10 This effect generally occurs if the core temperature (Tc) is kept below 38.5°C. However, it remains unclear how hypoxic exposure may affect these recommendations. The literature has independently
Effect of Wetsuit Use on Body Temperature and Swimming Performance During Training in the Pool: Recommendations for Open-Water Swimming Training With Wetsuits
Tomomi Fujimoto, Yuiko Matsuura, Yasuhiro Baba, and Reira Hara
swimming in low T w (≤25 °C), wearing a wetsuit has been reported to have advantages, such as maintaining body temperature and improving propelling proficiency. 5 , 10 – 13 On the other hand, during training in swimming pools ( T w : 26–30 °C) with a wetsuit on, their body core temperature may
Additional Clothing Increases Heat Load in Elite Female Rugby Sevens Players
Mitchell J. Henderson, Bryna C.R. Chrismas, Christopher J. Stevens, Andrew Novak, Job Fransen, Aaron J. Coutts, and Lee Taylor
) promotes physiological adaptations likely to benefit physical capacity/performance in such environments (eg, reduced resting/exercising core temperatures [Tc] and heart rates [HR], earlier and greater sweat response, greater plasma volume and exercise capacity 2 ). Typical physiological responses to match
Environmental and Psychophysical Heat Stress in Adolescent Tennis Athletes
Maria Misailidi, Konstantinos Mantzios, Christos Papakonstantinou, Leonidas G. Ioannou, and Andreas D. Flouris
minutes of warm-up and free fluid consumption. Three new tennis balls were used for each set with the players retrieving balls between points. Head–neck precooling included wearing a cooling cap (Welkinsmed, Downers Grove, IL) before warm-up until core temperature dropped by 0.5°C from its baseline value
Continuous Thermoregulatory Responses to a Mass-Participation 89-km Ultramarathon Road Race
Christopher Byrne, Aurelien Cosnefroy, Roger Eston, Jason K.W. Lee, and Tim Noakes
Ultramarathons, defined as running events longer than the marathon distance of 42.195 km, are characterized by a diversity of distance, duration, topography, and environmental conditions. 1 A key consideration for the ultramarathon runner is the regulation of body core temperature ( T c ), as the
Mild Dehydration Does Not Influence Performance Or Skeletal Muscle Metabolism During Simulated Ice Hockey Exercise In Men
Matthew S. Palmer, George J.F. Heigenhauser, MyLinh Duong, and Lawrence L. Spriet
This study determined whether mild dehydration influenced skeletal muscle glycogen use, core temperature or performance during high-intensity, intermittent cycle-based exercise in ice hockey players vs. staying hydrated with water. Eight males (21.6 ± 0.4 yr, 183.5 ± 1.6 cm, 83.9 ± 3.7 kg, 50.2 ± 1.9 ml·kg-1·min-1) performed two trials separated by 7 days. The protocol consisted of 3 periods (P) containing 10 × 45-s cycling bouts at ~133% VO2max, followed by 135 s of passive rest. Subjects drank no fluid and dehydrated during the protocol (NF), or maintained body mass by drinking WATER. Muscle biopsies were taken at rest, immediately before and after P3. Subjects were mildly dehydrated (-1.8% BM) at the end of P3 in the NF trial. There were no differences between the NF and WATER trials for glycogen use (P1+P2; 350.1 ± 31.9 vs. 413.2 ± 33.2, P3; 103.5 ± 16.2 vs. 131.5 ± 18.9 mmol·kg dm-1), core temperature (P1; 37.8 ± 0.1 vs. 37.7 ± 0.1, P2; 38.2 ± 0.1 vs. 38.1 ± 0.1, P3; 38.3 ± 0.1 vs. 38.2 ± 0.1 °C) or performance (P1; 156.3 ± 7.8 vs. 154.4 ± 8.2, P2; 150.5 ± 7.8 vs. 152.4 ± 8.3, P3; 144.1 ± 8.7 vs. 148.4 ± 8.7 kJ). This study demonstrated that typical dehydration experienced by ice hockey players (~1.8% BM loss), did not affect glycogen use, core temperature, or voluntary performance vs. staying hydrated by ingesting water during a cycle-based simulation of ice hockey exercise in a laboratory environment.
Responses of Motor-Sport Athletes to V8 Supercar Racing in Hot Conditions
Matt B. Brearley and James P. Finn
Background:
Despite the thermal challenge of demanding workloads performed in high cabin temperatures while wearing heavy heat-retardant clothing, information on physiological responses to racing V8 Supercars in hot conditions is not readily available.
Purpose:
To describe the thermal, cardiovascular, and perceptual strain on V8 Supercar drivers competing in hot conditions.
Methods:
Thermal strain was indicated by body-core temperature using an ingested thermosensitive pill. Cardiovascular strain was assessed from heart rate, hydration status, and sweat rate. Perceptual strain was estimated from self-rated thermal sensation, thermal discomfort (modified Gagge scales), perceived exertion (Borg scale), and perceptual strain index.
Results:
Prerace body-core temperatures were (mean ± SD) 37.7°C ± 0.4°C (range 37.0°C to 38.2°C), rising to 39.0°C ± 0.4°C (range 38.4°C to 39.7°C) postrace. Driver heart rates were >160 and >170 beats/min for 85.3% and 46.7% of racing, respectively. Sweat rates were 1.06 ± 0.12 L/h or 13.4 ± 1.2 mL · kg−1 · h−1, and postrace dehydration was 0.6% ± 0.6% of prerace body mass. Drivers rated thermal sensation as hot (10.3 ± 0.9), thermal discomfort as uncomfortable (3.1 ± 1.0), and perceived exertion as very hard to very, very hard (8.7 ± 1.7) after the races. Overall physiological and perceptual strain were 7.4 ± 1.0 and 7.1 ± 1.2, respectively.
Conclusions:
Despite the use of cooling, V8 Supercar drivers endure thermal, cardiovascular, and perceptual strain during brief driving bouts in hot conditions.
Warm-Up Practices in Elite Snowboard Athletes
Ben C. Sporer, Anita Cote, and Gordon Sleivert
Purpose:
The purpose of this project was to observe current warm-up practices in snowboard athletes and evaluate their physiological impact before competition.
Methods:
An observational design was used to monitor 4 athletes (2 female) at an Open National Snowboard Cross Championships. Activity patterns, core temperature, heart rate (HR), and time between warm-up and competition were measured. Athlete ratings of thermal comfort (TC) and thermal sensation (TS) were recorded before competition.
Results:
Significant barriers and challenges to an optimal warm-up included delays, environment, and logistics. Time gaps between structured warm-up and competition start time were in excess of 1 h (median = 68.8 min). Median average HR for 10 min (HR10) did not exceed 120 beats/min in the hour preceding competition, suggesting a suboptimal warmup intensity. Athletes rated their TC between comfortable and slightly uncomfortable and TS as neutral to slightly warm before the start of qualifications and finals.
Conclusions:
The observations of this project suggest significant gaps in current warm-up strategies used in snowboarding. These include inadequate general aerobic warm-up (based on intensity and duration), excessive time between warm-up and competition, and lack of a consistent and structured warm-up protocol. Future work is needed to evaluate the effectiveness of different warm-up strategies on muscle temperature and performance while determining the optimal length of time between warm-up and competition.
