This stationary bike delivers the same cardio benefit of a 45-minute run in an intense 8-minute ride — it took me just one session to realize the concept works, too

• With the AI-powered CAR.O.L exercise bike, you can get almost the same health benefits in an 8 minute, 40-second workout as you would in a standard 45-minute jog.
• The process starts with six introductory rides during which the bike gets to know your health and fitness baseline; after that, the challenges and progression system begins.
• By monitoring your biometrics in real-time and cross-referencing data it collects, the CAR.O.L bike customizes every session to ensure you get the most effective workout possible.

Bad news, folks: The whole "I don't have time for exercise" excuse won't work anymore. That's because with the new CAR.O.L at-home training bike, you can get the same cardio benefits that come from a moderately paced 45-minute jog in less than 10.

This innovative concept comes down to two key concepts: science and what can only be summed up as 40 seconds of hell. I decided to put both to the test to see if the bike can deliver on its seemingly far-out fitness claim. To my surprise, it mostly delivered.

Let's talk about the science first.

The science behind the CAR.O.L bike

When you eat food, particularly anything carb-rich, your body breaks down some of the nutrients into sugar glucose and stores most of it in your muscles as glycogen. Glycogen is, in simplest terms, muscle fuel – it's the stuff your muscles use when you lift, jog, or sprint (or do pretty much anything, really).

The more glycogen you have at the ready, the more you're able to exercise (aka, the better shape you're in). And the way to get more glycogen is to burn up as much of it as you can during frequent exercise sessions.

Serious exercise helps your muscles grow physically larger as they repair the little tears created in their fibers and signals your body to store more of that muscle fuel at the ready. This kind of intense exercise can take two basic shapes: a long, continuous exercise period, or a short and intense period.

The CAR.O.L bike hopes that, after a few months of using the bike regularly (three to four times a week), your body will have undergone a fundamental change. It's goal is to have your body adjust to rapid glycogen depletion and become instead become more efficient at turning to another energy source once glycogen runs low. That other energy source? Fat.

Setting up and using the CAR.O.L

My wife and I took the CAR.O.L bike out of its packaging, down into the laundry room, and fully assembled in just about an hour. The process was rather involved but there's a step-by-step instruction booklet and available video that make it hard mess it up. There's even a great customer service team, as well that helped us configure the bike out of some odd stand-by mode it was set to. Someone from the team walked me through the fix minutes after I reached out despite being UK-based.

The first time you use the CAR.O.L bike, the ride really won't be that hard — nor will it the second, third, fourth, fifth, or sixth time. Ride seven is where things start to get intense. The bike (more specifically, the computer within) has enough data by that time to establish your ideal heart rate for warm up, intense training, recovery, and cool down. It uses this to create a workout that's customized to be as challenging and productive as possible.

Here's how the primary eight-and-a-half-minute workout is broken down:

• Warm up: 2 minutes
• All-out sprint: 20 seconds
• Recovery: 3 minutes
• All-out sprint: 20 seconds
• Cool down: 3 minutes

And that's it. Eight minutes of relatively easy pedaling and two 20-second periods of the most difficult time on a bike possible. It even tells you via on-screen prompts exactly what to do, be it to pedal harder and faster, or when it's time to back down, and even when to take a big breath.

Do that three or four times a week for a few months and you just might be in the best shape of your life — that's the goal of the brand, at least. There are also tailored HIIT (high intensity interval training) workouts, like the 15-minute Fat Burn or, if you have the time, a longer 30-minute program.

A few nitpicks

There is one drawback to the CAR.O.L: the workout is almost too fast. I get it, that's the point (and this is likely an unpopular opinion). The bike saves you time and lets you get in a great training session, even when you're rushed but I personally love a long run or an hour-long gym class. So, sometimes being on and off the bike in less than 10 minutes makes using it less appealing (to me) rather than more appealing.

That said, on those days I want a longer exercise session to clear my head and enjoy an extended period of activity, it's not like I can't just go for a run or head out for a longer bike ride.

Another drawback is that the bike isn't exactly cheap, sporting a price tag of close to $3000. This puts it in a similar price bracket to other interactive stationary bikes like Peloton or NordicTrack, so if you're in the market for something like the CAR.O.L, it's probably not all that surprising.

The bottom line

I've been jogging, doing calisthenics, and lifting weights for more than a decade, and have gone to gym classes for the better part of a year, and I've never experienced a workout as efficient as what this bike offers. Though it doesn't do much of anything for your upper muscle groups or core, it's an incredible exercise that's impressively effective for your legs and cardiovascular system. If you're looking for an interactive stationary bike that offers a wholly different approach to what's currently available, CAR.O.L delivers.

• Should you buy it? Yes, as long as you actually think you'll use it. If it's going to sit there untouched one week, ridden four times the next, then untouched for a month, don't bother. You know yourself, so be honest – the whole approach only works with commitment. That said, if you can commit nine minutes thrice weekly, by all means dive in.

• What are your alternatives? This is a unique system given the amazing efficiency of the workout but there are other HIIT bikes out there that will give comparable results if you're willing to spend a bit more time. A Peloton bike is a fine alternative, especially if you like the idea of riding with others in a class. If you want the same intense exercise but don't love stationary biking, a smart rower like Hydrow or Ergatta offers custom workouts of varying intensity based on your fitness and goals — and row machines are an excellent source for a full-body workout.

Pros: Amazingly efficient bike that requires less than 10 minutes per session and just three sessions weekly for an effective cardio workout, customized workouts change as you get fitter, easy to setup and move as needed

Cons: Expensive, not an ideal fitness tool for people not already in decent shape