'You'll never lose weight going to the gym and exercise DOESN'T boost your mood': Leading expert busts common fitness myths

Dr Michael Mosley told ITV's This Morning the myths harm health and morale

Says our 'reward culture' after the gym means we're likely to gain weight

There is 'no evidence' that endorphins can travel through the brain barrier

And only 20% of us see a big difference in our fitness from regular exercise



Warning: Dr Michael Mosley appeared on ITV's This Morning to dispel common fitness myths

We're constantly being told that exercise is the panacea to many of life's ills.



Not only will it make us fitter, it will help us lose weight and boost our mental health.



But it seems this may have been wrong all along.



Exercise can actually cause us to gain weight - and there's no such thing as an 'endoprhin rush', one expert claims.

Dr Michael Mosley, the brains behind the popular 5:2 diet, says countless myths surrounding physical activity are hampering our health - and morale.



'A lot of people think that when you exercise, you can eat what you want - and that the gym will make you happy,' he told ITV's This Morning. 'But this is wrong.'

During the programme, he discussed the common myths that could do more harm than good.

Here, MailOnline outlines his key points...

GOING TO THE GYM CAN MAKE YOU FAT

The key problem is that we reward ourselves with 'treats' after exercise - or have the 'I've been to the gym, so I can eat what I want mentality', says Dr Mosley.

'Exercise is a good way to keep weight off - but it's not a good way to lose it.

'Going to the gym will burn calories - but way less than we think.



'1lb of fat is 3,500 calories - and fat is more energy-dense than dynamite' - so to burn 1lb of fat you'd need to run about 38 miles.'



He cites the example of a muffin and latte - which many of us underestimate the calorie content of.

'If you run one mile, you burn roughly 100 calories,' he told presenters Ruth Langsford and Eamonn Holmes.

'A muffin contains around 500 calories - so you would have to run for five miles or walk for 10 miles to burn it off.'

And when it comes to a latte - which has around 150 calories - it would be 1.5 miles of running or a three-mile (hour long) walk.

'That is why people never lose weight going to the gym in the long-run.'

Bad reward: 'A muffin contains around 500 calories - so you would have to run for five miles or walk for 10 to burn it off,' says Dr Mosley. A typical latte contains around 150 calories - and would take 1.5 miles of running or a three-mile (hour long) walk to shift



NOT EVERYONE GETS FITTER WITH EXERCISE

'There was an experiment which followed 100 people exercising for 30 minutes, five days a week,' Dr Mosley told viewers.

Over time, their metabolic fitness - the strength of their heart and lungs - was measured.

'While 20 per cent became significantly fitter, most didn't change that much and 20 per cent saw no change at all - they just didn't have the right genes,' he said.



'It is true - some people have a genetic make up that means they just can't lose weight.

'It can very demoralising and these people feel like a failure.'

He added that gym bunnies tend to be the 20 per cent of people who see significant improvements in their fitness.





Myth: While exercise can relieve symptoms of depression, this is more to do with being out in the fresh air rather than the release of 'feel-good' endorphins, Dr Mosley claims

EXERCISE DOESN'T RELEASE 'FEEL GOOD' ENDORPHINS

We're always being told this, but again, there is no scientific evidence for it, Dr Mosely told Ruth Langsford.



'The endorphin molecules are simply too big to cross the blood-brain barrier.



'I personally find exercise doesn't boost my mood at all.'

And while studies have shown exercise can relieve symptoms of depression, this is more to do with being out in the fresh air, he says.



'It's about getting out, clearing your head - whether that's walking the dog, playing golf, whatever,' he said.

FORGET SLOGGING IT OUT FOR AN H OUR - YOU CAN MAKE A DIFFERENCE IN MINUTES

In fact, evidence is increasingly showing that short bursts of high-intensity exercise are much more beneficial, he said.

Indeed, research published last week showed just two one-minute sessions a week for six weeks dramatically improved the health and physical fitness of men and women over 65.

Blood pressure dropped and everyday tasks such as getting out of a chair or carrying shopping became easier.

Although they began by doing six six-second sprints, by end of the study, they were able to do ten per session – adding up to 60 seconds of activity.

After just six weeks, blood pressure fell by 9 per cent and day-to-day activities were easier, the Journal of the American Geriatrics Society reports.

'Despite fears that high-intensity exercise could be dangerous for elderly people or those with existing heart conditions, it actually has a protective effect,' Dr Mosley said today.



BUT EXERCISE DOES REDUCE THE RISK OF CANCER

Half of people are unaware that lack of exercise can increase the risk of cancer – with as many wrongly blaming stress. A survey shows most people do not know that just 30 minutes of physical activity a day could reduce the risk of bowel, breast and womb cancer. But the YouGov poll commissioned by World Cancer Research Fund UK (WCRF) found 46 per cent of people believed stress increases the risk of cancer – despite the lack of scientific evidence. The survey showed 56 per cent of the 2,535 people questioned are in the dark about the link between too little physical activity and a greater risk of cancer. Professor Martin Wiseman, medical and scientific adviser at the WCRF, said: ‘For many people, stress makes them aware of problems that they had formerly ignored, or is a reason for seeking advice. ‘Stress might prompt them to become acutely conscious of an irritation or pain that they had previously tolerated. ‘It’s this stress that often pushes them to seek their doctor’s advice, and many automatically link the outcome to the recent stress and believe it to be the cause. ‘However, there is no sound scientific evidence that stress causes cancer.’ Professor Wiseman said as well as cutting weight gain, research shows activity has a direct role in preventing some cancers possibly by maintaining healthy hormone levels.