Take your workouts outside with rooftop barre classes and kayaks on the canal

It’s so hot that even if the ink on your newsprint is running, you most certainly are not. Your trainers have retired somewhere warm — the back of your cupboard.

Look, we’re really not complaining but how can anyone consider exercise when they’re already sweltering? Even the thought is exhausting. While the mercury rises, you’ve melted into a Tube seat, wondering if you’ll survive the journey, let alone 30 minutes in the gym. This is no longer a wave, it’s a full- blown heat invasion.

Adapt. Instead of pounding away on a treadmill inside, relish the parks , rivers and rooftops where lesser spotted gym fanatics migrate in the summer. Just make sure you take a water bottle.

The rooftop is your first port of call, where the air is thinner and the temperature cooler. This summer, the John Lewis roof in Oxford Street is populated by the lithe and Lycra-clad on Mondays, Wednesdays and Saturdays thanks to a pop-up by athleisure brand Pepper & Mayne (johnlewis.com). It hosts early morning Pilates, yoga and BodyBarre classes from 7.30am (10am on Saturday).

Across the city, yoga teacher Sophie Dear will be hosting a weekly hour-long Vinyasa flow class on the Madison restaurant bar’s rooftop, with breathtaking — then exhaling — views of St Paul’s Cathedral. The Bussey Building’s rooftop hosts drop-in yoga sessions six storeys up.

For something more down to earth, Train Dirty London’s bootcamps go into overdrive in the summer. These ferocious outdoor classes are set up in open spots across most of London, from Finsbury Park to Clapham Common (traindirtylondon.com). Combining high-intensity interval training (HIIT) with heavier weights, you’ll need all the fresh air you can get.

If your idea of a summer workout is less work, more play, try Frame’s low-impact Breakfast Barre class on the banks of the Regent’s Canal in King’s Cross. It’s a great way to start the day barefoot and sunkissed, set to Beyoncé and Britney Spears. Meanwhile, zorbing — the act of wilfully placing yourself within a plastic sphere and moving it around like a hamster wheel — has taken off.

You can walk, run or stumble on water at Merchant Square in Paddington Basin on August 10, taking your zorb out onto Regent’s Canal. It takes balls.

There’ll also be stand-up paddleboarding and one-off floating fitness sessions — more yoga, on a water stage to improve balance — with personal trainers (floated in specially).

Further down the canal, at St Mary’s Bridge on Thursday, the annual Dragon Boat race invites you to embrace your inner Viking and row hard for 100m. It’s also raising money for Children of St Mary’s Intensive Care, a local charity.

Rabble classes, in Finsbury Park and Clapham Common, disguise interval training as fun and games, instilling a “workout without noticing” approach. Dodgeball and British Bulldog games, train endurance, speed, agility and co-ordination. You can run up to 10K in a single class, so it’s not child’s play (joinrabble.com).

Tail-wagging? In Battersea Park, Barking Fit’s outdoor HIIT classes on Tuesdays are canine-friendly, building isometric exercises into your dog walk. Book through Move GB (movegb.com).

Make the outdoors great again. Get a move on.