For decades, VO2 max, movement economy, and fractional utilization of VO2max have been widely presented as three key determinants of endurance performance. But how strong is the evidence for that third piece?

Yannick Sondermann and Dr Lars Schwalm join us this week to challenge some long standing assumptions around fractional utilization and explore whether it truly deserves the weight it has been given in traditional endurance performance models.

Drawing on their recently published work, they unpack what fractional utilization actually represents, whether it changes meaningfully with training, and why improvements in the metric may not always mean what we think they do. They also explore VO2max, movement economy, durability, strength training, and what coaches should actually focus on when trying to improve performance.

The conversation ultimately comes back to a simple question: are we focusing on the variables we can actually change?

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Today's Speakers:

Prof Paul Laursen https://www.paullaursen.com/

Yannick Sondermann: https://www.linkedin.com/in/yannick-sondermann/

Dr. Lars Schwalm: https://www.linkedin.com/in/dr-lars-schwalm-223ab2420/

Resources:

https://journals.humankinetics.com/view/journals/ijspp/aop/article-10.1123-ijspp.2026-0039/article-10.1123-ijspp.2026-0039.xml