That Triathlon Show is the podcast for triathletes of all levels who want to train smarter and race faster. With over 600 episodes and millions of downloads since 2017, this show cuts through the noise and misinformation, delivering practical, no-nonsense advice rooted in both the art and science of training and performance.
The podcast features in-depth interviews with the world’s best coaches, top sports scientists, and elite athletes. Each episode dives into the nuances of training methodology, performance optimization, and race-day execution, providing insights you can apply right away. Whether you’re preparing for a supersprint or an Ironman, or focusing on a single sport like swimming, cycling, or running, you’ll find expert guidance and relevant content here.
The podcast is hosted by Mikael Eriksson, a former engineer now coaching professional and age-group athletes. Mikael is a Level III certified coach with over a decade of experience in coaching.
Join a global community of dedicated triathletes and take your performance to the next level. Learn more at www.scientifictriathlon.com/podcast.
With the Ironman World Championship in Kona this Saturday, this Research Roundup is a heat and humidity special for triathletes and other endurance athletes, built around four big topics instead of four single studies. How much heat and humidity each slow you down when you separate the two, what the largest reviews say about heat acclimation and whether sauna and hot baths work as well as active methods, how fast heat adaptations arrive and how fast they fade, and which in-race cooling strategies work, while also being practically feasible.
HIGHLIGHTS AND KEY TOPICS:
- Separating heat from humidity: a study that held the vapour pressure of the air constant from 18°C to 27°C and 36°C, then doubled it at 36°C, and why dew point is the number you want to check before a hot race.
- A meta-analysis of 135 studies and 1,531 participants: how short, medium and long heat acclimation protocols compare, and which of four approaches (constant work, isothermal, self-regulated and passive) comes out ahead.
- Sauna and hot baths after training: what a stricter meta-analysis of 10 controlled studies found, why the control groups matter so much, and the case for active heat training when time is short.
- How many heat sessions, how long and how hot: a review of 211 papers, the free online predictor that comes with it, and whether the sessions need to be on consecutive days.
- Five weeks of home-trainer heat sessions in 20 elite cyclists: when haemoglobin mass starts to move, how quickly the gains decay, and how to plan around these dynamics before racing.
- Four days of 90-minute heat sessions: what changed after such a short protocol, why time-to-exhaustion results look so much bigger than time trials, and whether feeling adapted without being adapted could backfire in an all-day race like an Ironman.
- Ice caps, a cooling neck collar, the Omius headband and water dousing in running studies: which ones improved performance, what they did to core temperature, and why Mikael ends up defending a gadget.
SHOWNOTES, LINKS, RESOURCES AND RELATED EPISODES:
- Follow Daniel Rowland on his website, Substack and Instagram
- The shownotes for today’s episode can be found here.
- The full podcast episode archives (including category filters) can be found here.
- Related episodes:
- How to Race the IRONMAN World Championship in Kona: A Complete Guide | Tomasz Kowalski
- Heat adaptation and triathlon performance with Stephen Cheung | EP#138
- Bent Rønnestad, PhD | EP#386
- Alistair Brownlee, Two-Time Olympic Champion | Everyone Was Surprised by How Slow I Trained
- Swimskins, Power Duration Curves and Best Bike Sessions for Runner Turned Cyclist | Q&A
- The “Best Practices” We Stand By That the Research Does Not Support
- 10 Triathlon Race Day Tips That Actually Make a Difference
- Strength and Speed Training Methods of Norwegian Endurance Coaches | Research Roundup
- The 10% Rule Applies to Your Long Run, Not Your Week | Research Roundup
- New Research on Torque Training, Ketones, Carb Loading and Pacing | Daniel Rowland
- Studies discussed:
- Delineating the impacts of air temperature and humidity for endurance exercise – Jenkins et al. 2023
- Effects of Heat Adaptation on Physiology, Perception, and Exercise Performance in the Heat: An Updated Meta-Analysis – Tyler et al. 2024 (ResearchGate link here)
- The effect of post-exercise heat exposure (passive heat acclimation) on endurance exercise performance: a systematic review and meta-analysis – Solomon and Laye 2025
- Influence of Exercise Heat Acclimation Protocol Characteristics on Adaptation Kinetics: A Quantitative Review With Bayesian Meta-Regressions – McDonald et al. 2025
- Time-course for onset and decay of physiological adaptations in endurance trained athletes undertaking prolonged heat acclimation training – Cubel et al. 2024
- Heat Training Efficiently Increases and Maintains Hemoglobin Mass and Temperate Endurance Performance in Elite Cyclists – Rønnestad et al. 2022
- Effectiveness of short-term isothermic-heat acclimation (4 days) on physical performance in moderately trained males – Shaw et al. 2022
- Effects of a Head-Cooling Cap on 5-Km Running Performance in the Heat – Spannagl et al. 2023
- Cooling the Neck Region During Exercise in the Heat – Tyler and Sunderland 2011
- Assessment of the Omius™ cooling headband effectiveness during a 70-min submaximal running effort followed by a 5-km time-trial in hot/humid conditions – Desroches et al. 2024
- The Effect of Water Dousing on Heat Strain and Performance During Endurance Running in the Heat – Anderson et al. 2024
- Tools mentioned:
SPONSORS:
- Precision Fuel & Hydration produce our favourite gels, sports drinks, and electrolyte and carbohydrate products here at That Triathlon Show and Scientific Triathlon. Use the free Fuel & Hydration Planner to get a personalised plan for your carbohydrate, sodium and fluid intake in your next event, and get 15% off your first 2026 order by using the code TTS2026 at checkout.
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LEARN MORE ABOUT SCIENTIFIC TRIATHLON:
- The Scientific Triathlon website is the home of That Triathlon Show and everything else that we do
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