Long-distance triathlon glossary·Fat Max

Fat adaptation: fat oxidation during exercise

Load

Ability to burn fat as primary fuel, key for long-distance endurance performance.

Fat adaptation refers to physiological adaptations that increase the body's capacity to oxidise fatty acids at moderate intensity (Z2). It develops through high Z2 volume, occasional fasted training, and low-carbohydrate nutrition on easy days. In an Ironman, a well-adapted athlete can burn over 1 g of fat per minute, sparing glycogen for high-intensity moments, especially the final run.

In TriPaced:

In TriPaced, long Z2 sessions (70-80 % of total volume) directly build fat adaptation. The planner prioritises this aerobic base in the Base and Build phases before introducing threshold blocks.

Source Volek et al., 2016: Metabolic characteristics of keto-adapted ultra-endurance athletes, Metabolism

Related terms

  • TSS : Training Stress Score
  • CTL : Chronic Training Load (fitness)
  • ATL : Acute Training Load (fatigue)
  • TSB : Training Stress Balance (freshness)
  • Sweet spot : the efficiency zone
  • Threshold : the upper sustainable limit