You don't need a PhD to know that dragging your partner clothes shopping is a waste of time. But some things, like exercise, are worth a team approach. A University of Pittsburgh, US, study showed women who work out with a partner lose a third more weight than those going it alone. Plus, exercise can rev your sex drive due to the increased blood flow to your bits. But few couples are matches made in fitness heaven. (Him in step class? Er, no.) Don't despair. Try these tricks from trainers, physiologists and fitness pros to get your butts moving together in no time.

You... Love to work out
He... Hasn't broken a sweat since high school

DO-IT-TOGETHER STRATEGY

Plan of attack: get him motivated. "Men are goal-oriented, so set up rewards for meeting small goals," says psychologist Dr Eleanor Cole. (Like when you bought yourself that new Stella gym bag.) It takes about four weeks - or, say, 12 trips to the gym - for exercise to become a habit. Get him addicted by offering a small incentive after every four workouts, like movie tickets for Quantum Of Solace (you'll benefit, too - hello, Daniel Craig). After he makes it to week four, cement his new habit with the 4-gig Sandisk Sansa Clip, a workout-friendly MP3 player ($133, sandisk.com.au).

If the gym isn't his thing, look for a mixed sports team to provide a steady play date on the field or court, suggests sports psychologist Dr Kate Hays. Do a search for "sports" on au.local.yahoo.com to find athletic leagues in your area. "Pick something different to what you're already good at," Hays says. If you play tennis Molik-style, he may start to lose motivation when he can't even return your serves.

You... Want to tone up
He... Wants to bulk up (but not become a hulk)

DO-IT-TOGETHER STRATEGY

Don't worry, lifting weights isn't going to turn either of you into a bulging muscle freak - unless you really want it to. What weight lifting does for you depends on the approach. To simply get lean and strong with weights, work large muscle groups like the back, chest and legs. "They burn the most kilojoules," says exercise physiologist Sheila Kalas.

Join your bloke when he's doing the following fat-obliterating exercises: squats, leg extensions and leg curls for the lower body; chest presses, flies, lat pull-downs and rows for the chest and back. To tone up and kill kilojoules, do one to three sets of 12 to 15 reps, using enough weight that your muscles are fatigued (but not spent) when you get to the last rep. To build mass, he should do three to five sets of 8 to 10 reps, using enough weight so that by the end of the last set, he can't do one more rep. Sick of waiting for your turn on the machine? Finish with a few time-saving, kilojoule-busting tandem moves like the three at right from fitness pro Michael Curry.

You... Play to win
He... Plays to totally annihilate the enemy

DO-IT-TOGETHER STRATEGY

Researchers at Penn State University, US, found that when women anticipate competition they get a surge of testosterone, which boosts the libido - you do the maths. Choose a workout strategy that plays off your "I love you but I'm going to kick your sweet arse" nature - without killing each other in the process.

If you're all about weights, you can keep his Schwarzenegger-size ego in check with this tip from strength and conditioning specialist Rachel Cosgrove who owns a gym with her partner: divide the number of kilos you're each lifting by your respective body weights and, voila, suddenly the playing field is level.

If you're more about cardio, run or bike together three times a week. Day 1, let him pick the route. Day 2, you devise the workout plan. Day 3, play Simon Says: do intervals, alternating who gets to set time, distance and style. "Our bodies love routine, but that gets us into a rut," Curry says. Mixing it up "shocks the muscles and you start burning major kilojoules".