Could going to the gym be making you fatter?

Remember your New Year's resolution to lose weight? Seems a long time ago, doesn't it. Maybe you cracked in the first week - or maybe, just maybe, you've stuck with it.

You've cut out the snacks, chocolate is but a memory, and you've dragged yourself to the gym every day. So why is it that instead of resembling Nicole Kidman, you still look like Dawn French?

The awful truth for every would-be slimmer is that going to the gym is unlikely to make you thin. It may even have the opposite effect: it could actually make you fatter. This will have personal trainers chewing their smelly insoles in fury, but there is sound science behind the theory that gym-going could actually impede weight loss.

The problem is the kind of exercise most dieters favour. Most eschew the weights area, inhabited by its hardcore of scary looking men.

'Women can have a block about weights,' says clinical psychologist Victor Thompson, who runs a specialist sports psychology practice. 'The fact is, many assume we have to be big and butch to lift weights, or, if we're not, that's how we'll end up looking.

'So your average dieter goes hell for leather on the treadmill, rowing machine or cross trainer. People see getting a sweat on as the way to burn calories.'

Dieters therefore tend to choose cardiovascular exercise, which works the big muscles of the body, for example the legs. It makes the heart work harder to pump more oxygenated blood to the muscles, so the lungs have to take in more air to provide this oxygen, which is why you feel out of breath.

However, while cardiovascular exercise might feel exhausting, the calories it burns are pretty pathetic. Thirty minutes on the rowing machine burns just 300 calories. That's 50 calories less than a 100g slice of pepperoni pizza.

Second, your appetite may adjust to a gym habit. 'Your appetite goes up when you start to exercise,' says David Archer, lecturer in exercise physiology at the University of Sunderland. 'Your body is telling you it needs more calories, so you eat more.'

What excess cardiovascular exercise may also do is cause us to break down important lean tissue as the body struggles to generate energy. This will then slow down our Basal Metabolic Rate (BMR) - the rate at which we burn calories just going about daily life.

'Fat is pretty inactive,' explains Archer. 'Lean tissue is four to five times more active, and burns more calories at rest.' So, the more muscle you have, the higher your BMR.

Losing lean tissue through excess cardiovascular exercise could set up the classic yo-yo dieting situation. You lose a huge amount of weight by going to the gym four times a week - but the moment you slacken off, the weight piles back on because you now have less muscle and a lower BMR.

And then there's the hormonal changes. 'Exercise causes rises in hormones, such as cortisol and growth hormones,' says Professor Paul Stewart, consultant endocrinologist at Queen Elizabeth Hospital in Birmingham.

Some experts have suggested a link between an excess of cortisol and fat storage.

The theory is that cortisol, as a stress hormone, is designed to prepare our bodies for 'fight or flight'. To do this, we need a ready supply of energy. So cortisol acts to raise our blood sugar through the production of new glucose (sugar) from protein and fat in the liver.

Raised blood sugar stimulates the release of the hormone, insulin, which can then lead to fat storage.

And that's just the start of your worries. Prof Stewart and his team at Birmingham University have been doing research into cortisol and its link to the body's metabolism. They have found that fat tissue itself, particularly the fat that many of us store round the middle, can actually manufacture cortisol, 'thereby promoting ongoing obesity'.

So, in theory, fat can actually make you even fatter.

You could at this point be forgiven for wanting to forget the whole gym thing. Still, there is a major caveat. Prof Stewart says: 'The gym culture is good for cardiovascular health.' So those punishing sessions on the treadmill or exercise bike are still important for our hearts and lungs.

And in terms of weight loss, it might not be time to throw in the gym towel, either. It could simply be a case of switching to the weights area of the gym.

Resistance exercise, such as lifting bar bells or working-out on weight machines, builds up lean tissue, therefore boosting BMR. Some of the hormonal responses to cardiovascular and resistance exercise may also differ.

Victor Thompson suggests three cardio and two resistance training sessions a week. He also advises steering clear of weight machines and going for dumb bells instead.

'With a machine, you don't have to use your core stability muscles. Aim for sets of 8 to 12 repetitions in each exercise.'

Prof Stewart has an even simpler solution: 'Long lasting weight reduction will only be achieved by a change in the balance between food intake and energy expenditure. What about a walk 30 minutes after every meal to help stabilise blood sugar? Gentle exercise may help us cope with the metabolic consequences of a meal.'

Now, doesn't that sound more attractive than half-killing yourself on the rowing machine?

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Devill said:

Very interesting.

It has been known for a while now that weight training burns more calories than cardio.

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blunomore said:

I was *told* that if you do a fair amount of cardio beforehand, your weight training will be more effective ... not sure if this was an untruth too ?

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cerebus said:

It's true you never see women at the weights section of the gym. They're all killing themselves on the rowing machines and stuff. I do about 15 minutes of running first. I find the stronger my running health is, the more energy I have. But I don't think it makes such a difference as free lifting to my body fat.

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blunomore said:

I was *told* that if you do a fair amount of cardio beforehand, your weight training will be more effective ... not sure if this was an untruth too ?

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Voicy said:

I can well imagine this to be true.

I lost 10kgs at the start of the year in 2 months while NOT going to gym. Purely by changing my diet and bodysurfing in the evenings after work. After joining up again, I plateau'd.

I used to do rowing for 45mins on the highest resistance, which absolutely killed me and did nothing else. Now I do resistance training after a 20min treadmill jog (because I suck at running with my treestomp legs )

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blunomore said:

3. It also helps doing cardio AFTER the weight or resistance training.

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blunomore said:

I was *told* that if you do a fair amount of cardio beforehand, your weight training will be more effective ... not sure if this was an untruth too ?

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Devill said:

Might help "warm" the muscles and get the blood pumping propperly but weight training (properly) keeps on working the muscles up to 6 hours after stopping IIRC.

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Mila said:

Blu i was told the same then:
I was *told* by the trainer that warming up before hand is important but after you do weights you should do 20 -40 min of cario. She said something about the muscles being warm and pumped form the weights make the cardio burn more after the weights than before. She is a Bio so she did a bit more studying than the avarage trainer so i think she might have a point?

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blunomore said:

Same here, Mila.

My trainer told me to warm up (10 mins or so), then do weights and then do 20 mins of cardio.

On my 'off' day - when I do not do weights - I do a full 40 mins of cardio.

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killadoob said:

I think there are many theories but nobody actually knows for sure.

So do what works for you and try different methods but i do not know which one is true all i know is that by doing cardio you do lose weight without a doubt.

Diet is more important than gym when trying to losing weight. Not more important as such but you will see bigger results by changing your diet than you would by going crazy at the gym and not changing it.

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