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Science

Your results, supported by science.

CAROL Bike was developed with leading exercise researchers to deliver the shortest, most effective workouts. Our signature REHIT workout creates the most potent training stimulus with just 2×20-second sprints. It’s scientifically proven to deliver superior health and fitness benefits compared to regular cardio exercise—in 90% less time.

How the REHIT adaptation pathway works

CAROL’s AI-personalization helps you push to your limits during the sprints. Like in a ‘fight or flight’ situation, your muscles are forced to mobilize about 25-30% of muscular glycogen—your emergency energy reserve—releasing key signalling molecules (AMPK and PGC-1a), telling your body it must get fitter and stronger.


You develop more mitochondria, your blood plasma volume increases, and your heart gets stronger. Resulting in increased aerobic and anaerobic capacity.

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