Coaching clinic

Britain's leading fitness experts answer your questions about training, injury prevention and diet

My knees hurt when I run. Should I give up?

No, not necessarily. You may need to reduce your mileage, change where you run or how often you run for a while, but once you have identified and rectified the cause of your knee pain, you should be able to return to regular running. A visit to a chartered physiotherapist who specialises in sport will help you do this. You may have increased your mileage too quickly or changed your route to include a lot more hills, for example - or you may have the wrong type of running shoes. These are simple things to change that could make a big difference to your symptoms.

The physiotherapist may also prescribe some specific stretching or strengthening exercises to restore flexibility or muscle balance that can affect the way you run.

• Dr Nicola Phillips, Team GB chief physiotherapist at the 2008 Olympic Games

I'm 12 years old and would love to be a runner. What's your advice about how to get started?

It is great to get involved with a good local club, where you can hook up with a junior running group. This makes your running more of a social experience, where you'll make good and lasting friendships. If injury or illness occurs, then these strong friendships will help you stay motivated and involved. Your training should be carefully thought about by a qualified coach. Take it gently and develop a good, solid foundation as a young runner. The key thing is not to get too excited about winning everything. Focus on enjoying your running and see where it takes you.

• Alex Stanton, Paula Radcliffe and Liz Yelling's coach

I seem to have reached a plateau with my training. Why aren't I improving any more?

Every runner hits a plateau in their training at some stage of their running career. It can be very frustrating, especially when you are still keen to improve. The secret to avoiding an ongoing plateau is to evaluate your performance regularly and identify what you can do to improve the situation. Every runner has areas that could be better, so be honest about your strengths and weaknesses. In my experience, some key areas to kickstart your improvement are greater strength - achieved through lots of hill work and cross-training - and good speed endurance, which requires efficient running at tempo pace for a good duration.

• Keith Anderson, former Commonwealth Games marathon runner and coach with Full Potential (fullpotential.co.uk)

I often use the treadmill. Is it as good as outdoor running?

The treadmill is a fantastic training tool, but it isn't identical to outdoor running, so if you plan to do any road races, it's advisable to do at least some of your training outside. The biomechanics and energy cost of running on a treadmill are not scientifically well understood, and some coaches believe it encourages a shorter stride length. The belt is moving beneath you, so in theory, it might be easier to cheat and put less effort into moving forward (the longer your flight time, the greater the belt rotation). A further factor is that there is no wind resistance indoors, which is why it's a good idea to set the treadmill's incline button to 1% to 2%, to more closely replicate the challenge of outdoor running. On the plus side, the treadmill allows you to monitor your performance easily, and it's a good option when conditions are unsafe or uninviting outside.

• Gavin Pavey, Jo Pavey's coach

What causes a stitch, and what can I do to prevent it?

There are several theories regarding what causes a stitch: the effect of food and fluid in the gut, changes in blood flow to the diaphragm as blood is shunted to the working muscles and irritation caused by two layers of membrane in the abdominal area rubbing against each other.

Here are a few suggestions to help prevent stitches:

• Allow two to four hours between eating a meal and training.

• Avoid high-fat foods: they take longer to digest.

• Ensure you are well hydrated before you start exercising.

• Drink little and often during training rather than large volumes all at once.

• Avoid highly concentrated drinks (fruit juice, soft drinks, hypertonic energy drinks) during training. Water or isotonic sports drinks are preferable.

• Increase training load gradually and warm up properly.

• If you do get a stitch while you are running, some popular relief options include slowing your pace, stopping altogether and bending forward, breathing deeply while pressing the painful area.

• Wendy Martinson, registered dietician and sports nutritionist to the British Olympic Association