You love lifting. You love the plain challenge and the simple rewards – beating your previous best and feeling a great pump afterwards. And maybe you hate cardio. Devoting gym time to cardiovascular exercise feels as if you’re burning away hard-earned muscle. But you’re not – you’re revealing it.

If gaining mass is all you focus on, soon no-one will be able to distinguish your traps from your deltoids. For a lean and chiselled physique, you need cardio work. Relax – no distance running involved.

Besides, you know you need aerobic exercise for a healthy heart. And a fit heart is more efficient at transporting blood and oxygen to working muscles. The stronger your heart, the stronger each of its contractions. That means more oxygenated blood is pumped out with each beat.

What follows is a set of rules to help lifters build healthy hearts. You don’t need much cardio work and most of what you do need should be at high intensity, as befits a man with a lifter’s mind-set. It’ll help you see more muscle definition without wasting time in the gym spinning your wheels.

RULE #1: CHANGE THE CYCLE

You don’t lift the same way all year, so why should the frequency, intensity and duration of your cardiovascular work-outs stay the same? They shouldn’t.

When you’re trying to add muscle, keep your aerobic work to a minimum – say, once or twice a week for 15 to 20 minutes. This will limit your energy expenditure and allow your body to concentrate on building muscle.

When you’re trying to get lean, increase your cardio training to two to four times a week to help strip away excess body fat.At all times, alternate your cardio methods so your work-out’s not too boring – treadmill running one day, rowing or elliptical training the next, cycling the day after that.

RULE #2: SEPARATE CARDIO FROM LIFTING

Serious lifters worry that cardiovascular training will impede their ability to recover from intense strength work. However, it all depends on when and how you do your cardio training.

Keep your cardio days and strength days as far removed from each other as possible. That way your cardio won’t hinder gains in strength and size. For instance, doing a tough cycling work-out after you hammer your legs with squats and lunges isn’t a good idea if your goal is to build bigger legs. Save your cardio for the next day or even two days later, to rest your legs.

If you must do cardio and weights on the same day, choose a form of aerobic work that emphasises body parts your weight-lifting didn’t focus on that day.

So, if your cardio choice is rowing, which works your upper body as much as it does your legs, hit the rower on a day when your weights session doesn’t concentrate on your upper body.

Whichever route you choose, just be sure to do the weights first. You don’t want to wipe yourself out before your weights routine – you won’t get the most out of your session and lifting when you’re tired can be dangerous.

RULE #3: DON’T MAKE AN IMPACT

Your body has enough to contend with in repairing the damage that lifting heavy weights inflicts on it. The last thing you need to do is break it down further with high-impact cardio training.

Concentrate on cardio work-outs that minimise microtrauma – the small tears to muscle fibres that are part of the process of building new muscle. Running on hard surfaces like asphalt or concrete can be traumatic to muscles and joints. Skipping can cause similar problems.

Your best bets for low-impact exercise are swimming, cycling and using an elliptical machine.

RULE #4: IGNORE THE “FAT-BURNING ZONE”

It’s a myth that you have to work out continuously for 20 minutes before you begin burning fat. The thinking once was that you needed to exercise in a range between 60 per cent and 80 per cent of your maximum heart rate. Any lower was too easy and any higher made it too difficult to efficiently use fat for fuel.

Ignore that theory. Your body uses more energy overall when training at high intensities – just look at the physique of a sprinter. Going all out also makes better use of your time. You can finish your cardio in an intense 10- to 15-minute work-out.

Stick to interval work-outs that feature short bursts of high-intensity movement followed by active recovery periods. (See the sample work-outs below.) This approach is best for your heart and for fat loss.

RULE #5: CHOOSE THE PATH OF MORE RESISTANCE

Changing the gears on a bike and altering the gradient on a treadmill, for instance, are great ways to increase intensity. Just be careful to find a level of resistance that won’t reduce the amount of work you’re able to do when you return to the weights room.

Now that you know the rules, follow these guidelines, depending on your goals: