VO2max : the aerobic ceiling
LoadThe maximum amount of oxygen your body can consume per minute (in ml/kg/min).
VO2max is the ceiling of your aerobic capacity. A beginner sits around 35-40 ml/kg/min, a trained age-group triathlete 55-65, world elite 75-85. Genetics and training contribute equally: you can gain 10-20% over your starting value with specific work across 1-2 seasons.
In TriPaced:
TriPaced prescribes short, intense VO2max sessions (3-5 min Z5 per block) during build phases. Not during taper (Friel ch.13: VO2max intervals are swapped for shorter Z3-Z4 activation sessions there).
Source Bassett & Howley, 2000 : Limiting factors for maximum oxygen uptake