In this episode of Endurance Insights, Coach Mark Cullen breaks down several common myths and misconceptions in endurance training—from why runners shouldn’t cover the full marathon distance in training to why VO₂ max and heart rate are often misunderstood metrics. Mark explains how building consistent weekly volume, developing durability, and progressing through different training intensities creates a stronger aerobic foundation than chasing extreme workouts or metrics promoted by influencers.

He also dives into practical performance topics including marathon fueling strategy, why most runners shouldn’t change their natural foot strike, how lactate thresholds actually work, and why fractional utilization matters more than simply having a high VO₂ max. The episode closes with a discussion on the limits of heart-rate training and why pace, power, and perceived effort remain the most reliable metrics for training and racing success.