The Science Of Energy System Training

This video is the latest iteration of a talk I’ve been giving over the past few years on the science of energy system training. Specifically, this talk debunks many of the common assumptions about how energy systems work and presents you with an updated model of bioenergetics that is informed by contemporary scientific research.

Below you’ll find timestamps and cliff notes corresponding to the various discussion topics I covered:

• [00:00 - 01:35]- Intro to Bioenergetics

• [00:00 - 05:00]- Classic Bioenergetics

  • Support of muscle contraction requires continuous PCr breakdown.

  • PCr consumption is >40x greater than previously believed

  • Traditional PCr measurements fail to capture continuous depletion and restoration on millisecond time scales.

• [05:00 - 05:45]- PCr & O2 Kinetics During Exercise

  • PCr and oxygen measurements are strongly correlated during and after exercise.

  • PCr and lactate hydrolysis are initiated at the onset of muscle contraction.

• [05:45 - 10:15]- Muscle Energetics

  • A review of the contemporary model of bioenergetics.

• [10:15 - 12:45]- All Training Is Aerobic

  • Blood lactate reflects the balance of production and consumption, not absolute lactate levels.

  • Oxygen utilization responds immediately to load at the onset of exercise.

  • Glycolysis is an inefficient method of energy production and reliance on glycolysis is secondary to oxygen depletion.

• [12:45 - 14:30]- Lactate and Fatigue

  • The role (or lack thereof) of lactate in fatigue.

• [14:30 - 18:00]- A United Model Of Bioenergetic Demands In Sport

  • Sprinting and distance running are both aerobic, but they differ in their respective maximal rates of oxygen utilization.