This episode was originally recorded for Dr Kate Baldwin’s podcast, The Distance Dr: In Practice, and is republished here with permission.

In this conversation, Kate and I unpack one of the most persistent ideas in endurance sport — that lighter is always faster. We explore where this belief comes from, how it has been reinforced through measurement culture and why it is often oversimplified or misapplied in practice.

The discussion spans body composition, adipose tissue physiology, muscle mass, bone health, injury risk and the limitations of common measurement tools. We also challenge the notion of “race weight,” reframing the conversation around performance readiness - the capacity to train consistently, recover well, remain healthy and perform when it matters.

While this conversation is relevant across endurance sport, there are particularly important implications for open water swimming, where buoyancy, insulation, thermoregulation, robustness and fatigue resistance all interact with the aquatic environment. Many of the assumptions carried over from land‑based sports simply don’t translate directly into the water.

This episode will be relevant not only to open water swimmers, but also to triathletes, runners, cyclists, coaches and clinicians who work with endurance athletes and want to take a more contextual, health‑first approach to performance.

You can find more of Kate’s work on her podcast, The Distance Dr: In Practice or via Instagram @thedistancedr