Running

She frequently sees what are termed stress fractures' - where a bone has been broken and soft tissue damaged as a result of over-exercise.

"Stress fractures are more common in females than males, and I have treated women with fractures on both their lower legs," she warned.

If women are overdoing it on the exercise front, one of the first things that will be affected will be their periods.

Doctor Newton, a rheumatologist specialising in sports medicine, explained: "A lot of women say that when they are running a lot, their periods become less regular or stop altogether."

"That is a sign that your body is not coping with the amount of exercise that you are doing," she cautioned.

Many women work out as a way of controlling their weight and according to Doctor Newton there is nothing wrong with that.

"If you are exercising to maintain a healthy weight and keep fit that is great but if you are doing it to stay unnaturally thin, that is not good," she said.

"We come across substitution', where people who used to have eating disorders have turned to over-exercising instead.

"I don't think it is a healthy look and it is not good for sporting performance to be that thin," she added.

She is also passionate about the fact that women should be mindful of the future health of their bones.

The main factor that determines whether or not you will suffer from the bone-thinning disease osteoporosis later in life is if you achieve a good peak bone mass in your teens and early 20s.

If you over exercise and your periods stop, you are much more at risk because, as you don't start off with as much bone mass, you haven't got as much to lose.

But when exercise routines stop being sensible and start being a liability, the solution does not have to be as dramatic as quitting exercise.

Often relatively minor adjustments in the amount and pace of training and diet can do the trick.

And on the basis that prevention is better than cure, if you haven't been physically active but want to take it up, it's a good idea to get professional advice, according to Doctor Newton.

"If you get it wrong it can put you off or even put you out of action. Then you decide you don't want to do it again and that is exactly what we don't want," she added.

Case studies Case A - Patient A was a woman runner who came to the clinic complaining of pains in her legs.

She explained she had upped her training distance quite considerably during a very short space of time.

An MRI scan revealed she was suffering from bone stress that would have certainly become stress fractures, had she not realised something was wrong and sought professional help.

On Doctor Newton's advice, she adjusted her training programme and was able to start running again within two or three weeks, instead of the three or four months it would have taken to recover from a stress fracture.

Case B - Patient B was a keen runner who had been trying to have a child for a long time but was unable to conceive.

When she attended the clinic and consulted Doctor Newton about problems with her legs, they discussed her training programme and diet.

As a result, she reduced the number of miles she ran each week and increased her food intake.

Much to her delight, she found she was pregnant shortly afterwards.

Here is Doctor Julia Newton's advice on how to exercise sensibly and to help avoid problems now and in later life: Running burns off approximately 90 calories a mile so it is important to replace that energy with calorie intake.

Training distance or levels shouldn't be increased by more than 10 percent each week.

Invest in proper footwear that will cushion the impact of the exercise.

Replace your training shoes every 500 miles. If you wait until they look ripped or very worn, they will have been useless for a long time.

With running, reduce the repetitive, sewing machine effect' on your bones by varying speeds and surfaces. Opt for a mixture of long, fast and cross country runs.

Concrete is the most unforgiving surface to run on. Tarmac is a bit kinder but cycle and off-road or grass tracks are better.

Listen to your body and ask yourself Have I increased my training programme too quickly?' or Am I getting lots of injury problems?' Make sure you have at least one exercise-free day each week to give your body time to recover.