The fitnesses classes where everyone can see your results in real time.

There are some workouts you don’t log on your Fitbit and share. The sort of efforts that are better kept as your own private fitness failure. However, that’s not really an option if you’re in a group session where everyone can see your results in real time, watch you plummet down the leaderboard, and call you out by name should you bolt for the door. Welcome to the word of the data-driven fitness class.

“There is no hiding,” says Mr Chris Elms, founder of heart-rate training studios YourZone45. The company launched its first studio in 2014; by the end of this year there will be nine in the UK, including one in London. “You’re in competition with yourself, but the heart rates provide a constant reference point to keep you motivated and allow the trainer to encourage people to work harder,” he says. Classes are 45 minutes (the optimum time to experience the benefits without fatigue) and members wear a heart-rate monitor throughout. The results burn bright on the studio data screen. The approach encourages excess post-exercise oxygen consumption (EPOC), which means your body will continue to burn calories after you’ve stopped exercising – studies have shown EPOC can last for up to 24 hours.

YourZone45 sessions feature cardio intervals, with at least 20 minutes of the class in the high-intensity “yellow zone”, which encourages weight loss, muscle mass gains and helps build strength and endurance, and technically equates to 80 to 90 per cent of your maximum heart rate for the session.

“Monitoring your fitness data gives you a better understanding of your performance over time and within a workout,” says Ms Catey Mark, director of strategy at Equinox, the London gym behind data-driven cycling class The Pursuit. “It’s only as useful as your ability to interpret and respond to it. Pursuit uses riders’ real-time data to push them to their max performance.” Ms Mark expects a new wave of data-tracking workout gear soon, such as “wireless headphones that capture your heart rate or clothing that gives you real-time haptic feedback on your form”, which allows your clothes and body to interact kinesthetically.

Last month, Third Space in London launched Poweride, a spin class that tests members’ power versus bodyweight and pits them against each other on a screen. “This is not for the faint hearted,” says class co-creator and master cycle trainer Ms Susie Millen. “It’s an endurance-based class with minimal recoveries. It’s for improving stamina and exertion.” Ms Millen recommends the class “for people training to do a leg of the Tour De France, a marathon or triathlons”.

You won’t find a slower pace at F45. The interval-training studios launched in 2014 in Australia, and there are now hundreds around the world, with 15 studios in the UK, and another 35 due to open by the end of 2018. Members wear its custom-made LionHeart heart-rate monitor, which feeds into a data screen, and sends a breakdown to them post workout. “We want the focus to be entirely on you, the moment and the workout, which is why there are no mirrors in F45 studios,” says founder Mr Rob Deutsch. “The screens demonstrate each exercise, how long to do it for, when to go, when to stop and even when to hydrate.”

Competition is at the heart of this fitness trend. These classes are built for those who like to dissect their workout, and for people who are already relatively fit. What if you’re not? “Ask for an introduction to learn the proper technique, and give yourself two to three weeks of settling in,” says Mr David Jordan, co-founder of London gym The Fitting Rooms. “Aim to increase your output by 5 to 10 per cent each week.”

If you don’t want to join a group in the real world you could take part virtually. New York-based Peloton will set you up with everything you need to create your own private cycling studio, with the teacher-led class, your stats and leaderboard displayed on a screen attached to your bike. Still in beta mode, UK-founded Flex offers a similar experience for group Hiit workouts via your TV and Apple Watch.

If you thought you needed determination to stick out a punishing data-driven workout IRL, you’ll need to find a whole new level of it to stop you switching off a virtual workout and collapsing on the sofa.