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carol bike

The CAR.O.L. Bike is a new exercise bike and workout program package designed to give you a full workout in just 40 seconds. (Well, 40 seconds of hard work, within a total of nine minutes per workout session.) Let’s see if it works and if it’s worth it – or if it’s absolutely ridiculous.

What is the CAROL AI Bike?

So many new exercise bikes have been promoted in recent years, it’s hard to stand out. But I found this bike claiming to provide an effective workout in just 40 seconds without breaking a sweat. And that caught my attention immediately!

The bike itself looks like any modern, high-end exercise bike: the Peloton, the Keiser M3i, or one of the nicer models from Schwinn or NordicTrack.

And it’s priced to match. The Carol bike starts at $2,595.

The key differentiator here is the AI software that calibrates your workout to be exactly what your body needs.

The Carol name is the name of the software, but they didn’t just choose “Carol” for no reason. And this is not, “Hey Carol, set a timer for 20 seconds.”

CAROL stands for Cardiovascular Optimization Logic. This AI-powered bike is sort of like a cycling coach, training plan, and power meter rolled into one.

It’s not just time-based workout regimens. Somehow the software determines the proper resistance for you, for each and every workout, based on your current fitness and fatigue levels.

You don’t have to worry about being in the proper gear ratio or watching your wattage. Just ride hard and let the AI do everything else.

What about the 40-second workout?

The claimed results – such as “improve cardio fitness by 12% in just 8 weeks” – are entirely realistic.

What’s hard to believe is how can you even do a workout in just 40 seconds?!

Well, you can’t. The prescribed workout is actually nine minutes long. But within those nine minutes, you do a lengthy warmup and cooldown. The actual high intensity work? A mere 40 seconds!

Here’s how it works out:

  • Two-minute warmup
  • 20-second sprint
  • Three-minute recovery interval
  • 20-second sprint
  • Three-minute cooldown

Yeah, it’s a little misleading.

But an entire workout in under 9 minutes and you actually see results? Impressive!

How can this work?

As it turns out, the claims of doing a workout in just 40 seconds are mainly for the “wow” factor.

They’re hoping you don’t read the details!

Because not only does that 40-second workout take 9 minutes, a lot of the claims are based on an entirely different 15 minute workout.

Here’s how they get you.

So they rope you in with these claims of how you can do a very brief workout and you won’t even break a sweat. But then whenever they make claims of how many calories you’re going to burn, those are based on this other 15 minute workout.

The big difference in the 15-minute workout is that you do 30 8-second sprints.

By my calculations, that is 240 seconds of intense exercise. An extra 200 seconds!

That is a legitimate workout. And that’s where they get most of their numbers.

Like this claim: “Burn more calories on a 15-minute CAROL ride than on a 30-minute run.”

Again, the claim is entirely realistic… depending on the intensity of the run!

You have to dig into the research study to find this info.

They actually did a scientific study on the CAROL Bike. It was published in the peer-reviewed journal, International Journal of Research in Exercise Physiology.

This allows them to say “science-based” or “backed by science” frequently. Well, what is the “science” here?

In a nutshell, the workouts on the CAROL Bike are interval workouts. It’s high intensity anaerobic work instead of long, slow, boring cardio. You’re working hard rather than racking up junk miles.

Related: Junk Miles: What They Are, And Why You Should Avoid Them

The problem is, that “interval workout vs junk miles” is how they designed their experiment. That’s an apples to oranges comparison if I’ve ever seen one!

They had participants do intense rides on the CAROL bike, and then “moderate intensity rides” (basically a 30 minute recovery ride) and “vigorous intensity rides” (20 minutes of junk miles) to facilitate the comparisons.

Are you the least bit surprised the CAROL bike workouts were more effective?

(Plus, they say the workouts are “rides” but later refer to them as “treadmill exercise” so it’s all a bit misleading. Or at least, confusing!)

This is High Intensity Interval Training (HIIT)

The reason this works is not by anything special about the bike or even because of the AI software involved.

It works because intense exercise works.

It’s mostly based on the same High Intensity Interval Training (HIIT) principles you’re already familiar with. Where weight loss is not so much about calories burned during the workout, but because you burn extra calories throughout the day after your workout (EPOC).

This time it’s a variation: Reduced-Exertion High-Intensity Interval Training (REHIT).

At a high level, REHIT is the same as HIIT, but doing less of it.

(Put in cycling terms, HIIT would be your 30-120 second work intervals. REHIT would be your sprint training with 8-20 second intervals.)

Most of the credit for this goes to Dr. Niels Vollaard. He performed a meta-analysis of existing research and determined you could likely see impressive VO2 Max improvements with less actual work than typical HIIT workouts.

Part of the idea is that most people are incapable of HIIT. Outside of competitive athletes, people don’t have the physical strength – and definitely not the willpower – to push their bodies at that intensity for that long (with “that long” being not really that long).

That’s great that this can open up the health benefits of high intensity training to a wider audience, but does it really necessitate the creation of this overpriced exercise bike?

CAROL Bike Pricing

Exercise bikes are expensive. Let’s see where the CAROL bike fits in.

What does the CAROL Bike cost?

With pricing starting at $2,595, the CAROL Bike is way overpriced. It’s actually more expensive than the Peloton bike, and you do basically the same workout every time. There are no fitness classes with spunky instructors as part of the CAROL AI software.

What really blows my mind is how you have to pay a $15/month membership fee to get access to the AI software responsible for customizing the workouts.

Shelling out the $2500 for the bike gets you… a stationary bike. The AI software, which calculates the exact right amount of resistance to provide during your sprints – and is the main selling point for the bike – is not included. You have to pay monthly if you want to access it.

Maybe it’s a good value?

While expensive, it’s possible the bike is a good value. The value would come from you actually using the bike and seeing results, whether that be improved fitness or weight loss (or both).

The bike does have good customer reviews on TrustPilot. And I don’t doubt the “before and after” success stories you see on Reddit. It’s fairly evident that some people achieve their weight loss goals thanks to this bike.

After all, spending thousands of dollars on workout equipment and monthly membership fees is a pretty good motivator to actually put in the work!

But it doesn’t seem cost effective to me.

Just get a traditional stationary bike + the Peloton app and you’ll get better workouts for much less money.

CAROL Bike Alternatives

If you’re looking for general fitness, you can get similar bikes for less money.

If you’re a cyclist, there are much better options for riding indoors.

The best CAROL Bike alternatives.

There are plenty of other options to do basically the same thing and spend less money. You could even spend less and still get a better bike.

If money is no concern, pick up a Keiser M3i. This is a very, very high-quality stationary bike. And you can buy the bike with accessories like a mat and tablet holder, for less than the price of the CAROL Bike. (The package is roughly $2500.)

A less expensive alternative is the NordicTrack S22i. This is a commercial-quality exercise bike like you’d find in a fancy health club. This bike has a 22″ HD touchscreen display that truly puts the CAROL Bike to shame. (Priced around $1500.)

There are other nice bikes from Schwinn, Echelon, and others. There is no shortage of stationary bikes!

The key is to find one where you can program your own workouts. Just program a custom interval setup using the same REHIT method that’s found in the Carol Bike.

What about a CAROL app?

Maybe someday they’ll release a Carol bike app that integrates with existing smart trainers or other connected exercise bikes. Then you could get the benefits of their AI at a more reasonable price (say, $15/month).

It would be a lot more sensible to just be a software business anyway. I mean, just look at the state of Peloton (the business). They offer great classes, a great experience, and have raving fans because of that. But they can’t make the bikes and make a profit at the same time.

I bet some talented coder will whip something up – if they haven’t already! And then you can do your 40 second workout on any smart/connected stationary bike.

Bottom line: It’s Ridiculous

After browsing the CarolBike.com website, reviewing their scientific research study, and doing some price comparisons, I have determined the CAROL Bike is ridiculous.

It comes down to two main reasons:

1. The sheer lack of workload in their Intense workout (it’s just two 20 second sprints, for a total of 40 seconds of work).
2. Why would you need fancy AI for that?

You simply can’t think of this bike as a form of training for a competitive athlete.

It’s not even a worthy Peloton alternative.

If you’re capable of – and willing to endure – 45+ minute workouts with high intensity, you have no use for this bike.

I guess what we need to keep in mind is that cyclists are definitely not the target market for this bike. This is product that’s going to appeal to non-cyclists.

Regardless, what is the point of AI right here?

There is no point. You can do this REHIT workout on any stationary bike, or on your regular bike on a stationary trainer.

There are many great uses for AI in the world, but this is not one of them.

There is only one potential customer I see for this bike.

Perhaps a former competitive athlete who is now a super busy business executive. One who needs a bike in their office and a workout they can do quickly, without changing clothes.

They could use the CAROL Bike and do the 40 second workouts right there, without breaking a sweat, and without worrying about a greasy chain. Their time is so valuable that it’s worth relying on the AI to make the decisions on resistance level.

This could be just enough training during the week that they can make the most of a big Zwift workout or real bike ride on Sunday.

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