Fitness myth busted: You can't control where on your body you lose weight from.

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In a dream world we’d get to choose exactly which areas on our body we shed excess weight from first.

It seems to make sense: you want to get rid of trouble spots on your thighs, so you take up jogging. Carrying some excess baggage around the midsection? Must be time to increase the sit-ups and throw in some planks for good measure.

Unfortunately, when it comes to fat loss, we don’t live a dream world. The human body is a complicated organism and we don’t have any say in where we lose — or gain — weight.

Even more annoyingly, for most of us, the first place we put fat on is usually the last place it comes off.

Fat as fuel.

For your body to burn fat as fuel, a complicated set of processes must first take place.

Fat is stored in our cells as triglycerides, but in order for your muscles to use it, your system needs to break it down into free fatty acids and glycerol, which are transported into your bloodstream to then be used as fuel.

The fat being used comes from anywhere and everywhere in your body, not the area you’re working at the time.

Studies on targeted fat loss date back to as far as the early 1970s, when University of California researchers compared the limbs of tennis players.

They discovered that despite the athletes being one-arm dominant, the subcutaneous (top layer) fat percentage between limbs was the same.

The University of Connecticut conducted a study in 2007 using resistance training and got a similar result.

Where your body loses fat from first comes down to your sex, genetics and body shape, explains exercise physiologist Brooke Norgate.

“Some women are apple-shaped (store fat around the midsection), some are pears (store fat around the waist and bum). Many men are apples as well,” she explains.

“There are probably many more women who are pear shaped because of our boobs, bums and hormones.

“We’re more likely to hold onto weight in those areas hormonally for child bearing.”

Trifecta of fat loss.

You might not be able to control where fat takes a hike from first, but you can make sure you’re doing enough exercise to lose weight from somewhere.

“To reduce body fat you need to be burning more calories than you’re consuming,” Ms Norgate explains.

“So if you’re doing something as little as a sit-up to lose belly fat, you’re not getting much burn at all.

“Essentially you’re just strengthening the muscle fibres underneath — not impacting the body fat tissue.”

Lifting heavy weights in certain areas through strength training, such as your lower-body, for example, will increase the muscle size, but it won’t make much difference to the subcutaneous fat that sits on top.

The most effective way to change your body shape, Ms Norgate explains, is by getting a decent mix of strength training, high-intensity interval training (HIIT) and cardio, such as walking, running, cycling or swimming.

Lifting weights will stop you from losing muscle when you’re dropping weight, plus lean muscle burns calories, even when you’re not exercising.

When lifting weights for fat loss, it’s best to do higher repetitions of full-body exercises, rather than those that use muscle at a time.

We burn the most calories through aerobic training, so to lose fat it’s important to do several sessions a week, with a mix of high-intensity and steady-state work.

There are many ways to do high-intensity training, but it’s important to get your heart rate to 90 per cent of its maximum.

One method, developed by Dr Tony Boutagy, adjunct associate lecturer at the University of the Sunshine Coast, is to work at 90 per cent for a minimum of 10 minutes.

For example, you could run for 30 seconds at 90 per cent, then rest for 30 seconds. Do this for eight minutes, then completely rest for two minutes. Repeat the eight minutes three more times.

If you’re new to HIIT, get the help of a personal trainer who can show you how to do them properly.

They’re hard to do and if not done right are either useless, because you’re not working hard enough, or you might find yourself injured.

Doing a good mix means you’re getting the best of both worlds, explains Ms Norgate.

“You’ll still have a spike in metabolism after training from the high-intensity and resistance training, plus you’ll get a high calorie burn from the cardio during your session,” she said.

If HIIT’s not your thing you can still lose weight from cardio, but you’ll have to put in more hours. The beauty of HIIT is that it’s time effective. You get the same calorie burn in half the time of going for a jog.

But overall, brisk walks, cycling or jogging, will improve your fitness and ensure you get more out of your training sessions.

Exercise aside, if you’re not eating a healthy, well-balanced diet, it doesn’t matter how many hours you put in at the gym.

So if you’re trying to lose weight, remember that you need to be burning more calories than you consume.

You know what they say: you can’t outrun a bad diet.

Do you get a good mix of exercises in when you’re working out?

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This post originally appeared on ABC News.