In this ground-breaking, tell-all episode, Kolie needles Kyle before he pulls at a thread, and Kyle's yarn untangles the skein of reality and explains how you can use the underlying fabric of the universe to bring your cycling performance to the next level.
Former national time trial champion Cory Lockwood fields questions from Kolie and podcast listeners about the ins and outs of time trialing, including his #1 tip for time trialists of all levels. We cover pacing, gearing and equipment selection, and mental focus. Plus we talk about how Cory's current training is going, fueling for big workout days, the team behind a big performance, and the unexpected usefulness of mirrors and plastic wrap. All while his cats try to steal mic time.
Does your training zone determine the fiber type used? Does fiber type determine aerobic or anaerobic pathways, carbs or fats? We answer these questions by looking at evidence and concepts that show that fast twitch fibers can be just as aerobically capable as slow twitch fibers, nearly as good at burning fats, and why that might be. We dissect a paper on elite cross-country skiers, and another paper on whether or not fast twitch fibers had been recruited at relatively low intensity. In-depth discussion follows on fiber type distribution, muscle mass recruitment and force availability, why endurance athletes defy the expected metabolic properties of fast twitch fibers, and why these expectations may have started with cats.
XC Skiers paper
The Muscle Fiber Profiles, Mitochondrial Content, and Enzyme Activities of the Exceptionally Well-Trained Arm and Leg Muscles of Elite Cross-Country Skiers
Ramp test muscle recruitment paper
Progressive metabolite changes in individual human muscle fibers with increasing work rates
Kolie makes his case that power meters are rendering lactate testing obsolete for most cyclists. After some background about lactate and why lactate testing was (and still is) historically crucial for science, we compare lactate test values in ramp and MLSS tests between individuals from an excellent but under-appreciated study. We also dig deep into more recent data, from the lactate test of a former world champion and Kolie's own surprising MLSS test, and the physiology explaining these results. We conclude with practical considerations about what threshold means, and why power meters are our best way to measure it.
Justification of the 4mmol/L lactate threshold
Lactate kinetics in human tissues at rest and during exercise (contains figure from episode cover art)
The maximal metabolic steady state: redefining the 'gold standard'
Alterations of the lactic acid content of the blood as a result of light exercise, and associated changes in the CO2 -combining power of the blood and in the alveolar CO2 pressure (Owles paper)
Lactate kinetics and individual anaerobic threshold