Episode Details

This week, Corrine Malcolm and Keely Henninger nerd out on what actually happens inside your body during — and after — an ultramarathon. Using recent research alongside what we already know about endurance physiology, they work system by system through the muscle damage, inflammation, kidney stress, cardiovascular changes, neurological fatigue, immune response, metabolic shifts, and GI issues that can come with pushing your body for hours on end.

They also dig into the difference between normal post-race weirdness and something worth paying closer attention to, why recovery can take much longer than simply waiting for sore legs to disappear, and what we still don’t know about the long-term effects of repeatedly racing and training at ultra-endurance volumes. Along the way, they talk about CK and rhabdo, acute kidney injury, post-race hypotension, heart remodeling, cognitive fatigue, RED-S, GI distress, and why fueling, hydration, sleep, and adequate recovery matter so much.

It’s a science-heavy conversation about what your body is actually managing when you ask it to run really, really far — and why understanding that process can help you recover better and keep doing this sport for the long haul.

That last paragraph is the framing I like most for this one: not “ultrarunning is secretly killing you,” but “this is an enormous physiological event, so maybe give your body some respect afterward.”