Scientific Triathlon (That Triathlon Show)

Physiological Profiling: The Triathlete's Guide to Smarter Training

The episode introduces physiological profiling as a systematic way to map a triathlete’s power‑duration and speed‑duration curves, linking those curves to underlying muscle‑fiber composition. By categorising athletes as fast‑twitch dominant, slow‑twitch dominant, or somewhere in between, coaches can align training zones—LT1, LT2, V̇O₂max, and fractional utilization—to each athlete’s natural strengths and weaknesses. Jack Hutchkins describes how his track background produced a glycolytic, fast‑twitch profile that required added tempo work, while Michael Ericson’s endurance‑oriented history favors high‑volume, threshold‑focused sessions. They stress that the shape of the curve dictates the balance of aerobic versus anaerobic work, and that fast‑twitch athletes fatigue more quickly and recover slower, making fatigue‑management heuristics essential. Practical examples include using race and training data to construct a power‑duration curve, then confirming it with a single‑day 5‑minute and 20‑minute critical‑power test or a 200‑meter and 800‑meter critical‑speed swim test. They also reference Phil Bellinger’s research linking muscle‑fiber typology to over‑reaching risk, underscoring the scientific basis for their approach. The takeaway for coaches and athletes is clear: profiling enables precise training prescriptions, optimises recovery, and reduces the likelihood of over‑training. By matching intensity distribution to an athlete’s physiological makeup, triathletes can improve performance across sprint, Olympic, and 70.3 distances while managing fatigue more effectively.