Hot Water Immersion and Overtraining with Sam Oliver & Robbie McIntyre | KoopCast Episode 170
Episode overview:
Dr. Robbie McIntyre graduated from the University of Stirling with a BSc (Hons) degree in Sport and Exercise Science before going on to do his MSc in Exercise Physiology at Loughborough University. He then completed his PhD at Bangor University, where he specialized in preparatory strategies for exercise in hot environments.
Dr. Sam Oliver Reader (Assoc Prof) in Sport & Exercise Science, and Director of the Institute for Applied Human Physiology (IAHP) at Bangor University, Wales, UK. Much of his work focuses on developing strategies to improve the health and performance of those people required to operate in challenging environments, this includes athletes, but also armed and emergency services.
Episode highlights:
(20:12) Mean body temperature: a useful non-localized metric for investigating heat training, ice slushies as an example of localized temperature reduction, challenges of the ice slushie intervention, previous podcast discussing heat training protocols with Lindsay Golich
(24:15) Comfort in hot environments: hot water immersion improved perceptual comfort and RPE, emphasizing that reducing RPE in the heat is key, athletes should feel more prepared
(41:40) Hot water immersion protocol: immersing in 40° C water post-run, increasing duration from 20min, safety, 3-6 days of immersion
Our conversation:
(0:00) Introduction: introducing techniques for heat acclimation training, non-disruptive heat acclimation proves most effective, introducing Sam and Robbie
(2:39) Setup: environment can limit performance, ultrarunners historically contrive strange protocols
(4:00) Sam’s background: environmental physiology, optimizing health and performance in difficult environments, studying athletes and soldiers
(5:44) Robbie’s background: heat acclimation strategies, exercise physiology
(6:25) Study setup: thyroid hormones, balancing running training and heat training
(8:18) Study design: sample population, comparing hot water immersion with exercise heat acclimation over 12 days, investigating the mechanisms behind heat acclimation, standard exercise acclimation protocol
(12:39) Hot water immersion versus dry sauna: why the study focuses on hot water immersion, practicality for athletes without access to a sauna, convenience is key
(14:47) Measuring overtraining: sleep, cognitive function, performance testing, blood lactate, mood, encapsulating stress from heat training
(17:18) Study results: core temperature as a key metric of heat training, mean body temperature as a pioneering metric, greater reductions in core and mean body temperatures following hot water immersion
(20:12) Mean body temperature: a useful non-localized metric for investigating heat training, ice slushies as an example of localized temperature reduction, challenges of the ice slushie intervention, previous podcast discussing heat training protocols with Lindsay Golich
(24:15) Comfort in hot environments: hot water immersion improved perceptual comfort and RPE, emphasizing that reducing RPE in the heat is key, athletes should feel more prepared
(28:23) Overtraining results: athletes avoid interventions that reduce training, using many metrics to determine overtraining, no differences in overtraining between heat training methods
(31:37) Research limitations: amateur athletes are not at their maximum training load so all interventions help, at the elite level the tradeoff may not be worthwhile
(34:07) Heat training elite athletes: evidence for heat training sub-elite but high level athletes, heat training can be individualized, revisiting the difficulties in getting athletes to substitute training
(37:51) Heat acclimation timing: benefits of hot water immersion therapy last at least two weeks, this grants athletes and coaches flexibility for programming
(39:18) Two phase heat acclimation protocols: one heat protocol 8 weeks before the event, a lower intensity heat protocol 2 weeks before the event, course correction, individual variation, bookending hard training with heat acclimation
(41:40) Hot water immersion protocol: immersing in 40° C water post-run, increasing duration from 20min, safety, 3-6 days of immersion
(44:42) Hot water immersion safety: heat immersion after moderate exercise, stand up slowly after immersion, stay within recommended bounds, take it easy
(46:30) More is not better: immersion duration is limited by core temperature and safety, examples
(49:34) Safety-related programming considerations: avoiding elevating your core temperature too high, incorporating rest days after 4 baths
(51:40) Most adaptations are chronic: endurance takes months or years to build, getting the best bang for your buck with relatively acute heat interventions, diminishing returns
(53:27) Wrap-up: giving thanks, where to find Sam and Robbie, reach out with questions, extrapolating the research
(56:36) Outro: heat acclimation is an effective tool, the intervention can be simple, share the KoopCast
Additional resources:
Podcast with Lindsay Golich
Buy Training Essentials for Ultrarunning on Amazon or Audible
Information on coaching-
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Twitter/Instagram- @jasonkoop