The Science of Aerobic Efficiency And How to Train It

In this episode of the Athletes Compass podcast, the team breaks down aerobic efficiency—what it is, why it matters, and how it may be more important than VO2 max for long-term endurance performance. They explore the physiology behind efficiency, including mitochondrial development and capillary density, and explain practical ways to measure it using metrics like efficiency factor and aerobic decoupling. The conversation highlights the importance of low-intensity training, strength work, and recovery, while challenging the common “go hard all the time” mindset. The takeaway: slowing down and building a strong aerobic base is the key to unlocking sustainable speed and performance.Key TakeawaysAerobic efficiency = how much speed or power you produce per unit of oxygenImprovements come from mitochondrial growth, capillary density, and fiber-type adaptationsEfficiency Factor (EF) and Aerobic Decoupling are key metrics to track progressLower heart rate at the same pace/power = improved efficiencyZone 1–2 training is the most effective way to build aerobic efficiencyToo much high-intensity training can limit long-term progressStrength training improves efficiency by increasing force productionExternal stress (heat, altitude, life stress) can negatively impact efficiency metricsConsistency matters more than intensity spikesGains can happen at any age—but require patience and repetitionPaul Warloski - Simple Endurance CoachingMarjaana Rakai | Nordic Performance Lab