What if the reason you're not exercising isn't laziness — it's that no one told you it could take five minutes?

In this episode of Why Isn't Everyone Doing This?, Emily sits down with Ulrich Dempfle, mechanical engineer and co-founder of Carol Bike, to explore a form of exercise most people have never heard of — and that science says is the most efficient workout on the planet.

Ulrich introduces ReHIT — Reduced Exertion High Intensity Interval Training — a five-minute workout with just two 20-second all-out sprints that has been clinically shown to produce a 12% improvement in VO2 max in just eight weeks with only two to three sessions per week. He breaks down why VO2 max is the single most important health marker for longevity, why low cardiorespiratory fitness causes more preventable deaths than smoking, diabetes, and obesity combined, and why the "no pain, no gain" belief is keeping most people from getting healthy at all.

Emily connects the science to her own experience — linking the fight-or-flight spike of a sprint to hormesis, mitochondrial biogenesis, and heart rate variability — and why intentional, acute stress is the perfect complement to the chronic stress release she's spent 17 years teaching through meditation.

In this episode, they explore:

Key Moments:

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