The best way to lose fat? Torch calories lying down. No, that doesn’t mean the bench press. Rather, by stoking your fat furnace to shed blubber even when you’re not in the gym.

Confused? Consider your car. An idling engine burns fuel even when it’s still. Ditto for your body. You might be asleep, but your cells aren’t; they need energy to rebuild, to digest food = all those little processes that ensure you’ll actually wake up tomorrow.

This energy – the calories you need to not die – goes by the snappy moniker of basal metabolic rate (BMR). And the average man needs around 1,600 a day – about three times what you’d torch in a spin class.

To reverse back to our motoring metaphor, any time you’re not lying in bed, your foot’s on the accelerator. Walk the dog? That’s 20 minutes at 2,000 revs. Run to work? You rev harder for longer – and need to visit the pumps sooner. Then when you stop moving, your body goes back to ticking over. The smart man puts a brick on the pedal.

Train right and your body goes into ‘oxygen debt’: your muscles work harder than your lungs can supply, so they turn to new fuels for energy, says Dylan Jones, celebrity personal trainer and the founder of P4 Body. The burn you feel is lactic acid, the byproduct of working beyond your body’s comfort zone. For the next two days, it needs more oxygen – and burns more calories – to recover, a process called excess post-exercise oxygen consumption (or EPOC).

The result is a revved up metabolism that lasts for up to 48 hours. Translation? “You burn more calories even when you’re in bed,” says Jones. But this fat-frying win doesn’t come easy. “You can’t just do 45 minutes on the cross trainer. You have to work as hard as you possibly can.” As in, can’t-get-enough-oxygen-into-your-heaving-lungs hard. But the ends justify the cruel and unusual means. You’ll bid adieu to a few hundred extra calories a day, doing absolutely nothing.

The 20-Minute Afterburn Circuit

Bicep curls won’t produce afterburn. “The more muscles you use, the more oxygen you require,” says Jones. With total-body moves, demand outstrips supply. But effort is all. If you can chat, work harder, bro. You should be sucking down air like you’ve just surfaced from a freedive.

Perform 40 seconds of each move at maximum intensity, take 20 seconds rest, then move onto the next exercise. Complete the entire circuit four times. If it’s too hard, shift to 30 seconds of work, 30 seconds of rest. If it’s too easy, then 50 on, 10 off.

Ice Skaters

Stand with your feet together. Squat down, then jump explosively off your right leg and land on your left. Repeat each side for the full time.

“Most people focus on forward-backward movements, but this works your body in a lateral plane,” says Jones. Focus on bending your legs and driving up explosively, to fire up your big leg muscles – and get that all-important oxygen debt.

Diver Bomber Press-Up

Start in a downward dog position – bent at the waist with your feet and palms on the floor. Your back should be straight, your glutes in the air. From here, tip your weight forward so your chest swoops towards the floor. Focus on keeping your legs and back as straight as possible. Hold at the bottom, then press your torso up but keep your hips near the ground.

“This hits more muscles than an ordinary press-up,” says Jones. “Your chest and arms but also your back, your legs, your core.”

Ali Shuffle

Tap The Greatest for this heart rate-spiking shadow box. Stand with your feet together, arms in a boxer’s guard. Throw a punch with your right hand, simultaneously jumping into a lunge with your left foot back.

Throw punches – and swap legs – for the full time. Your shoulders should sting like a swarm of bees.

Bag Throws

Stand with a sandbag on the ground between your legs. Squat down, grab it, then drive up through heels and hips to launch it over your head. Run to where it lands and repeat.

“This works all the muscles in your posterior chain,” says Jones. That burn in your back now means afterburn for your belly tomorrow.

Core Leg Sweeps

Eddy Gordo – favourite of Tekken button-mashers and owner of a fat-free physique. Channel his battle-ready breakdance by getting in a press-up position, then rotate your torso to bring your right leg under your body and up towards your left hand. You should finish with both hands behind you and your leg extended in front. Return and repeat with the left leg.

“This is the real killer,” says Jones. “You’ll definitely be in afterburn at this point.” The next three rounds are just fuel on the fire.