Why Your VO₂ Max Isn’t Rising

VO₂ max is one of endurance sport’s most closely watched metrics, but what does it mean when the number refuses to rise? Paul Warloski and Dr. Paul Laursen explain why a plateau—particularly for experienced and older athletes—can actually indicate successful training. They explore the roles of aging, genetics, aerobic volume, Zone 1 and Zone 2 work, high-intensity intervals, fat oxidation, recovery, nutrition, and life stress. The central message is that VO₂ max development isn’t about finding a shortcut or completing ever-harder workouts. A strong aerobic foundation, carefully controlled intensity, consistency, and sufficient recovery matter more—and improvements in fitness and performance can occur even when the VO₂ max number itself barely changes.

Key Episode TakeawaysMaintaining VO₂ max can be a win. Because VO₂ max tends to decline with age, an older athlete who keeps the same number may actually be outperforming the expected age-related trajectory.Your training history matters. Someone relatively new to endurance training may have considerable room to improve VO₂ max, while a lifelong, highly trained athlete is likely much closer to their ceiling.Aerobic volume comes first. Laursen describes consistent low-intensity training as the foundation, with HIIT being more like the “icing on the cake.”Zone 1 and Zone 2 help prepare you to absorb hard training. Greater aerobic development supports recovery and may make subsequent high-intensity work more productive.Both long and short intervals can work. Examples include 2–5 minute VO₂ max intervals, 1 km running repeats, 4 x 4-minute sessions, and 30/30 intervals.Five-minute power or pace can be a useful external marker. Laursen describes maximal sustainable output around five minutes as closely associated with VO₂ max.Don’t chase heart rate during short VO₂ max intervals. Because heart rate responds with a lag, pace or power is a more useful variable for controlling the session.Going harder isn’t automatically better. Starting too aggressively can reduce the total quality work you accumulate. The aim is controlled time above threshold rather than a “hero workout.”Fat oxidation may matter even at high intensity. A study discussed in the episode found fat oxidation distinguished elite orienteers from recreational athletes despite other measures being similar.Older athletes may need more recovery. One or perhaps two hard sessions per week may be more appropriate than the three an athlete could tolerate when younger, depending on individual recovery.Be skeptical of dramatic VO₂ max “hacks.” The episode argues that consistent progressive training, aerobic volume, HIIT, nutrition, and recovery remain the major levers.Life stress counts as training stress. Poor recovery and elevated overall stress may interfere with adaptations, making sleep, relaxation, and workload management part of the performance equation.

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