It’s not surprising there’s a buzz around HIIT. In our time-poor world, it offers a lot of bang for the buck.

As Gede Foster, creative master trainer of boutique operator, Frame, explains: “HIIT classes offer the opportunity to get a lot of exercise done in a short amount of time. Intense intervals challenge the body and you carry on burning calories after the workout, due to high post-exercise energy-consumption.

Due to its popularity, HIIT isn’t an off-peak option and many operators are reporting the need to keep upping the number of classes to satisfy demand.

Early morning, lunchtime and evening slots are optimal, as HIIT appeals to people who want to fit exercise around their work. Generally, HIIT appeals to the exercise-savvy; it’s not an entry-level activity.

Marco Coppola, head of health and fitness at GLL which runs more than 400 classes a week across its portfolio, reports constant demand for HIIT all year round, with a spike in the summer months. “Participants are typically from our pre-paid member base. Around three quarters of them are female, with the average age of participants around 27 years of age,” he says.

Pure Gym offers HIIT classes at all of its 200 sites. “Members love the fact they can get a great workout in less time and we try to educate them on the wider benefits of HIIT, such as an increase in metabolism and the all-important ‘after burn’ effect,” says Dave Cross, head of group exercise. “Generally we offer at least three Pure Fatburn classes per club each week at varying times, as well as incorporating HIIT principles into other classes.”

Refreshing the concept
As with all concepts, the classes need to be regularly refreshed in order to retain appeal and audiences. Local authority operator, Everyone Active, launched its HIIT offering – called EA 30 – in 2016. “We’ve found having our HIIT sessions in a smaller group environment is really appealing to customers, as it means more one-on-one time for participants and allows instructors to adapt exercises, so each person is working to their own ability,” says Mark Talley, group fitness development manager. “They’re also great for customers who might feel slightly intimidated by a larger group environment.”

In order to create a buzz in the gym and ease waiting time for equipment during peak hours, Everyone Active runs its HIIT sessions on the gym floor. The HIIT format of a 30-minute class with a warm up, cool down and two rounds of exercises in between has proven so popular that Everyone Active now runs some of its other group exercise classes in the same format.

Introducing equipment
The Gym Group introduced HIIT in early 2016. Initially, using classes from external providers, but then decided to create its own range of four 30-minute concepts using functional training equipment such as kettlebells. “Customers love it because it offers group training in a motivational environment, appeals to all fitness levels, and only takes 30 minutes,” says Gym Group's head of regions – north, Jon Baker.

Classes take place in a large, designated functional training zone, using 14 exercise stations. “There are classes for aerobic and muscular endurance; fat loss; strength and power and one which is a very challenging mix of all fitness components,” says Baker.

“Rather than being a generic offering, with minimal coaching, we allow members to choose which class suits their current fitness goals and then tailor each circuit station to their abilities. No two classes are the same. This specificity is the key to our class concept, and why they’re so effective and popular, as we tune in to the individual and really engage with them,” says Baker.

New fusions
Frame has also played with the HIIT concept, incorporating weights, treadmills and rowing into classes. “We have several formats – we run classes like Frame Cardio and Box Train, which consist of speed and incline intervals on the treadmill; speed and distance on the rower; body weight or weighted, floor-based intervals and boxing combos,” says Foster. “HIIT strength consists of compound strength-based weighted exercises, teamed with body-weight, fast-paced moves. Our latest addition is HIIT & Chill, which mixes speed, strength, plyometric and isometric movements to create the HIIT element and then follows this with a sound bath with binaural beats therapy and a meditation session to work right across all the energy systems.”

David Lloyd Leisure uses Les Mills GRIT, at its 30 UK clubs. The full-service operator has also launched a heart rate zone training, boutique studio class called Blaze, which incorporates treadmill, strength and combat conditioning intervals. “The short duration and promise of a high calorie burn, makes these classes very popular,” says Elaine Denton, DLL’s group health and fitness support manager.

Going forward, Denton predicts HIIT will penetrate other genres of group exercise. David Lloyd Clubs already offers Les Mills Sprint and HIIT cycling, which are both based on indoor bikes, but Denton believes there will also be more hybrid classes emerging, such a Frame's HIIT & Chilll, which fuse HIIT and things like holistic concepts for the ultimate yin and yang experience.