Swimskins, Power Duration Curves and Best Bike Sessions for Runner Turned Cyclist | Q&A

Listener Q&A, covering nine different questions/topics from building bike power as a runner and a collegiate swimmer moving back into triathlon, through what actually makes us fatigue during a threshold effort, to swimskins, power duration curves and lots more. We do listener Q&As monthly, the last Thursday every month. HIGHLIGHTS AND KEY TOPICS: Building the bike as a runner: why heart rate sits lower on the bike than on the run, whether that gap matters, and what it says about where the limiter is. Plus how to use a daily 20 km ride towing a 25 kg dog trailer. A 193 cm, 100 kg collegiate swimmer moving back into triathlon: the engine-stronger-than-the-chassis problem, a run progression specified down to the minute, and why Mikael gets more conservative every time he coaches this profile. Why the maximal lactate steady state is a steady state for lactate and not for the whole body, what keeps drifting while lactate holds flat, and what one study found when it looked for the system that fails at exhaustion. How long you can actually hold MLSS, against the 40 minutes the question assumed, how much that varies between athletes, and where critical power sits relative to it. Swimskins: whether they give you any of the buoyancy a wetsuit does, the performance, drag and energy cost numbers from the closest pool research, and the thing that matters more than the brand and price tag. Whether a swimskin does more for a fast swimmer or a slow one. Reading your own power duration curve with nobody to compare against: the TrainingPeaks chart to start from, why a flat profile means something different for a triathlete than a cyclist, and Strava as a stand-in database. Mikael's W’ bands for male and female age group triathletes, on record for the first time, plus the critical power ratio from close to a hundred of his own athletes' tests. Quickfire round on altitude, heat and the CORE sensor, run volume by intensity, and vegan nutrition. SHOWNOTES, LINKS, RESOURCES AND RELATED EPISODES: Jack Hutchens is a triathlon and endurance performance coach with Scientific Triathlon and a professional long course triathlete. Follow Jack on his coach page 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: The "Best Practices" We Stand By That the Research Does Not Support | EP#711 Beginner Series 7 - Running for beginner triathletes Related studies: Why does exercise terminate at the maximal lactate steady state intensity? - Baron et al. 2007 Slow-Twitch Fiber Glycogen Depletion Elevates Moderate-Exercise Fast-Twitch Fiber Activity and O2 Uptake - Krustrup et al. 2004 Time to Exhaustion at Traditional Physiological Indicators in Runners: Between-Subject and Between-Day Variability - Pallares et al. 2026 Effect of Fastskin Suits on Performance, Drag, and Energy Cost of Swimming - Chatard and Wilson 2008 Comparison of buoyancy, passive and net active drag forces between Fastskin and standard swimsuits - Benjanuvatra et al. 2002 Reliability and Validity of the CORE Sensor to Assess Core Body Temperature during Cycling Exercise - Verdel et al. 2021 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. Rouvy is hands down the most complete indoor cycling platform for triathletes. Among their thousands of beautiful bike courses from all around the world, all filmed in stunning quality, they have over 75 IRONMAN and IRONMAN 70.3 race courses plus 20+ Challenge Family courses, so you can pre-ride your race from home. Real gradients, real visuals, and real feel! Head to rouvy.com and use the code TTS to get your first month free on top of a 7-day free trial. Effortless Swimming produce the best swim goggles for triathletes and open water swimmers. Their NanoClear anti-fog lenses give you clear, fog-free vision that lasts and doesn't wear off. Don't let foggy or leaky goggles ruin another swim. 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