Trick up your workout with these simple techniques to burn more fat at the gym.      1. Aim for 3-7 repsTo boost metabolism, you want fewer reps with heavier weights according to the Norwegian University of Sport and Physical Education. To maximise calorie burn after your workout (a.k.a. excess post-exercise oxygen consumption or EPOC), aim for three to seven reps.   2. Combine loadsWhile lifting heavy and slow optimises afterburn, there’s something to be said for lighter weights. While they won’t buy you free on-couch calorie burn, researchers at the College of New Jersey say lighter weights may burn more kJs in session. The smart money’s on splicing heavy and light sets – try heavy for three to seven reps and light for 10 to 20. If that’s too easy, do two sets of heavy, two sets of light.   3. Rest lessTo elevate calorie burn by around 50 per cent, reduce rest time between sets from three minutes to 30 seconds, suggest College of New Jersey researchers.   4. Go hard or go homeWhile controlled moves demand more energy than loose ones, don’t take that as a cue to move in slow-mo. Lifting with explosive movements will engage more fast-twitch muscle fibres, which chew through more fuel than their slow-twitch peers according to a study at Ball State University. Choose a weight about 30 per cent of your 1 rep max (1RM), which means one you can lift 15 to 35 times per exercise. Complete four to five sets comprising two fast sets of three to eight reps and two to three at normal speed.   5. Rock the beatFiring up your Soundcloud before you hit the treadmill is a secret fat-burn weapon. In a study presented to the National Strength and Conditioning Association, those who worked out to their favourite playlist logged greater intensity and fat loss. Listening to tunes correlated with significantly higher reps than silence.   6. Reverse chargesIf you usually tack resistance onto the end of a cardio workout, you’re cutting off your nose to spite your fat loss. Fix? Switch the order. According to Japanese researchers, doing resistance before cardio results in greater fat burn. Better news: assuming it’s high intensity, you can cut your cardio to 15 minutes, which is the window in which the burn is highest.   7. Short circuitTo really make your cardio work, chunk it into short stints at near-maximum exertion. Try high-intensity interval training (HIIT) at 90 per cent of your maximum heart rate (MHR) augmented by stints at walking pace. Most steady-state cardio demands 60 to 70 MHR. Try the 20/10 rule (sprint for 20 seconds, walk or jog for 10).   8. Take a breakHaven’t got the endurance to stay on the bike for 30 minutes? Not an excuse to not work out. In fact, one study found that breaking your cardio into 10-minute bursts broken by 20-minute rests resulted in greater fat burn and higher EPOC.   9. Delay the playCan’t fathom getting up at the crack of dawn? Good, because you’ll burn more calories per session after work. In a University of Wisconsin study, participants who exercised for half an hour between 5 and 7pm raised metabolic rate more than morning exercisers – as measured by post-workout calorie burn. End-of-day sessions also trumped lunchtime workouts.   10. Ring a bellKettlebells can add a serious calorie burn premium to a HIIT workout. The combination of weight load, heart rate elevation and whole-body movement makes kettlebells an all-in-one winner according to exercise physiologist Richard Garard. Try using them in eight 20-second intervals, aiming for maximum swings per round. By round five or six you should be flagging. WARNING: If you’re new to kettlebells, enlist a trainer for a single session to teach you proper form. These things can be dangerous.   NEXT: How many calories are in your coffee? {nomultithumb}