Exercise in environments such as hypoxia or heat acutely increases physiological strain and reduces performance capacity. 1 – 3 Repeated exposure to hypoxia drives hematological and muscular adaptations to improve aerobic capacity in both hypoxic and normoxic environments. 4 Heat training and
Erin L. McCleave, Katie M. Slattery, Rob Duffield, Philo U. Saunders, Avish P. Sharma, Stephen Crowcroft and Aaron J. Coutts
Samuel Chalmers, Adrian Esterman, Roger Eston and Kevin Norton
Athletes often seek the minimum required time that might elicit a physiological or performance change. It is reasonable to suggest that heat training may improve aerobic-based performance in mild conditions. Therefore, rather than providing a traditional heat-exposure stimulus (ie, 7–10 × 60–100 min sessions), the current article details 2 studies that aimed to determine the effect of brief (≤240 min exposure) heat training on the second lactate threshold (LT2) in mild conditions.
Forty-one participants completed 5 (study 1, n = 18) or 4 (study 2, n = 23) perceptually regulated treadmill exercise training sessions in 35°C and 30% relative humidity (RH) (experimental group) or 19°C and 30% RH (control group). Preincremental and postincremental exercise testing occurred in mild conditions (19°C and 30% RH). Linear mixed-effects models analyzed the change in LT2.
Heat training did not substantially change LT2 in either study 1 (+1.2%, d = 0.38, P = .248) or study 2 (+1.9%, d = 0.42, P = .163). LT2 was not substantially changed in the control group in study 1 (+1.3%, d = 0.43, P = .193), but a within-group change was evident in study 2 (+2.3%, d = 1.04, P = .001).
Brief heat training was inadequate to improve the speed at LT2 in mild conditions more than comparable training in mild conditions. The brief nature of the heattraining protocol did not allow adaptations to develop to the extent required to potentially confer a performance advantage in an environment that is less thermally stressful than the training conditions.
Martin Buchheit, Yannick Cholley and Philippe Lambert
To examine in elite soccer players after traveling across 6 time zones some psychometric and physiological responses to a competitive camp in the heat.
Data from 12 elite professional players (24.6 ± 5.3 y) were analyzed. They participated in an 8-d preseason summer training camp in Asia (heat index 34.9°C ± 2.4°C). Players’ activity was collected during all training sessions and the friendly game using 15-Hz GPS. Perceived training/playing load was estimated using session rating of perceived exertion (RPE) and training/match duration. Psychometric measures of wellness were collected on awakening before, during, and after the camp using simple questionnaires. Heart-rate (HR) response to a submaximal 4-min run (12 km/h) and the ratio between velocity and force-load (accelerometer-derived measure, a marker of neuromuscular efficiency) response to four ~60-m runs (22–24 km/h) were collected before, at the end of, and after the camp.
After a large increase, the RPE:m/min ratio decreased substantially throughout the camp. There were possible small increases in perceived fatigue and small decreases in subjective sleep quality on the 6th day. There were also likely moderate (~3%) decreases in HR response to the submaximal run, both at the end of and after the camp, which were contemporary to possible small (~8%) and most likely moderate (~19%) improvements in neuromuscular efficiency, respectively.
Despite transient increases in fatigue and reduced subjective sleep quality by the end of the camp, these elite players showed clear signs of heat acclimatization that were associated with improved cardiovascular fitness and neuromuscular running efficiency.
David N. Borg, Ian B. Stewart, John O. Osborne, Christopher Drovandi, Joseph T. Costello, Jamie Stanley and Geoffrey M. Minett
-based training, using session-RPE as the primary indicator of TL. It was hypothesized that (1) cold-water recovery would reduce session-RPE TL and (2) hot-water immersion would increase session-RPE TL, compared with heat training with passive recovery. Methods Subjects Eight healthy males (Table 1 ), classified
Philo U. Saunders, Laura A. Garvican-Lewis, Robert F. Chapman and Julien D. Périard
complete an acclimatization regimen as close as possible to the competition being held in the heat. Heat Training for Improved Performance in Temperate Conditions In recent years, there has been a noticeable shift in trying to use heat acclimation to provide an added benefit to performance in cool
Blake D. McLean, Kevin White, Christopher J. Gore and Justin Kemp
. As previous longitudinal data show that PV is suppressed during colder months, 11 this cold exposure may have contributed to lower PV. In addition to cold environments, positive heat adaptations can be blunted when heat training interventions are combined with living in hypoxia. 12 McCleave et
Christopher John Stevens, Megan L. Ross, Julien D. Périard, Brent S. Vallance and Louise M. Burke
-hot (25°C–35°C) weather training for at least one month, before a further 3-week heat training camp prior to race 4, which involved regular training sessions in T air between 35°C and 45°C. Design The study investigated the rectal temperature ( T re ) response of the athletes across 4 outdoor events
Cyril Schmit, Rob Duffield, Christophe Hausswirth, Jeanick Brisswalter and Yann Le Meur
option to maintain training intensity over a HA training camp could be to schedule high-intensity HA protocol including recovery days or low-intensity heat training after a high-intensity exercise session in temperate conditions. 29 , 30 A limit of the present study was that only one performance test
Louise M. Burke, Linda M. Castell, Douglas J. Casa, Graeme L. Close, Ricardo J. S. Costa, Ben Desbrow, Shona L. Halson, Dana M. Lis, Anna K. Melin, Peter Peeling, Philo U. Saunders, Gary J. Slater, Jennifer Sygo, Oliver C. Witard, Stéphane Bermon and Trent Stellingwerff
of altitude training camps to improve their sea-level performance. Similarly, the use of heat acclimation/acclimatization to optimize performance in hot/humid environmental conditions (e.g., 2019 IAAF Doha World Championships) is a common and well-supported practice. However, the use of heat training
Alan J. McCubbin, Bethanie A. Allanson, Joanne N. Caldwell Odgers, Michelle M. Cort, Ricardo J.S. Costa, Gregory R. Cox, Siobhan T. Crawshay, Ben Desbrow, Eliza G. Freney, Stephanie K. Gaskell, David Hughes, Chris Irwin, Ollie Jay, Benita J. Lalor, Megan L.R. Ross, Gregory Shaw, Julien D. Périard and Louise M. Burke
heat acclimation is the most important intervention that athletes can undertake in preparation for competing in the heat ( Racinais et al., 2015 ), the process of becoming acclimated can be challenging. Notably, athletes may need to adjust absolute training intensity and volume during heat training