Short
The whole ride is done in 5 minutes — warm-up, two sprints, cooldown. Three rides a week is all the habit asks of you.
5:00 ridePodcast listener offer
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Chris Williamsonon CAROL Bike
Why it works
The most efficient workout there is.
Short and easy to fit into your life, smart enough to meet you exactly where you are, and proven in peer-reviewed research.
Smart
AI-personalized workouts calibrate resistance to you at every moment — simple to perform and suitable for any age and fitness level.
Any fitness levelScientific
Scientifically proven to deliver superior health and fitness benefits in 90% less time compared to regular cardio.
−90% timeInside the ride
Two 20-second sprints. That’s the workout.
Developed by leading scientists, Reduced Exertion HIIT (REHIT) creates the most powerful training stimulus from the shortest possible ride. CAROL’s AI applies exactly the right resistance at exactly the right moment — here is every second of it.
Pedal slowly for up to 2 minutes to prep for your first sprint.
AI applies Instant Resistance. You push to your limits for 20 seconds, forcing 25-30% mobilization of muscular glycogen, releasing key signaling molecules.
Pedal slowly for 3 minutes, clearing lactate and preparing for your second sprint.
Push again to your limits for 20 seconds to activate the signaling molecules released in Sprint 1. This tells your body it must get fitter, stronger.
Light pedalling for 3 minutes, so blood pressure, heart rate, and breathing go back to normal.
The research
Your results, backed by science.
CAROL Bike is scientifically researched and proven to improve your fitness and health. Just 3x5-minute REHIT rides a week.
+12%cardio fitness (VO2max) in just 8 weeks
10 yrsa 12% VO2max gain is like turning your fitness age back a decade
−62%risk of type 2 diabetes; blood pressure down 5%
2×more calories burned on a 15-minute CAROL ride than a 30-minute run
More on the science
Beyond REHIT, CAROL is a fully customizable indoor bike: Free Ride with control over timing, resistance and target power, plus Zwift, YouTube and Netflix integration.
Rider results
Hear it from our riders.
Our riders are at the heart of everything we do — and their fitness scores do the talking. Join our 35,000+ rider community.
All rider reviewsI’ve been training for a half marathon and since adding CAROL Bike to my daily routine in the past 2 weeks, my VO2max has gone up 5% already.
My CAROL Bike has been great to help me achieve greater fitness and power without the time investment but with all the fun!
In just 4 months, my VO2max has increased by about 12 points, and my heart rate has decreased by 10 bpm. For someone with a history of heart issues, these improvements are huge!
Dropping 2.6% bodyfat in ~8 weeks for someone who prioritizes a healthy lifestyle is no easy feat. I’d go so far as to label it as a gamechanger.
It’s easy to fit a quick 5-minute workout in, especially if you don’t need to shower after your workout!
I get more cardiovascular benefit in 5 minutes than I used to get from 30-minute runs, and my recovery is faster too.
The offer
Good habits start here.
Order CAROL Bike now, try it at home for 100 days, and build a habit that lasts.
100-day trial
Feel the benefits risk-free for 100 days. Not for you? Return it, no questions asked.
Delivery from $99
Delivered to your door, ready for your first calibration ride.
0% APR financing
Pay just $232.92/month at 0% APR, with Affirm.
Fitness Advisors
All our experts have MScs in Exercise Science — here to help you reach your goals.
CAROL Bike — $2,795
Save $300 with code MODERNWISDOM at checkout
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