Whether it's five km, a half marathon or a full marathon, more and more people across Sussex are getting involved in running.

Many of them are new to long-distance events and health experts are warning people to follow a series of measures to make sure they do well.

The key is to prevent overtraining from inexperienced runners and avoid injury which can make what was supposed to be a fun-run, agony.

Andy Ellis, exercise physiologist for Bupa in Sussex, said: "Whether you're preparing for a half marathon or are new to running, you could feel quite tired and sore as your training progresses.

"If so, it is important to remember your body needs to build up muscle between each training session.

"If you don't give your body the time it needs to recover after exercising, you will increase your chance of an injury."

There are several ways to avert injuries.

Avoid over-training. It is extremely important to increase your workload slowly when you start a new exercise regime.

Runners should not increase their weekly mileage at a rate faster than 15 per cent.

Beware over-developing just one aspect of your fitness.

Mr Ellis said: "You are less likely to get injured if you have a good level of overall fitness, including muscular strength, flexibility, aerobic capacity and general conditioning.

"Overall fitness is best achieved by cross-training in a number of different activities. For example if you are a runner, adding sessions of cycling, stretching and weight-training will help to develop your fitness without overworking the muscles and joints involved in running."

Use the right equipment and ensure you have well-fitting shoes. They help to protect your feet from the impact of landing and can also correct and balance any biomechanical errors in your running technique.

The training shoes you need depend on the sport.

Running requires shoes that support forward motion, while tennis needs shoes that support side-to-side movement.

Eating well and staying hydrated will help your body to meet the demands of a rigorous exercise programme.

You should follow standard healthy eating guidelines.

For most people, this means choosing lower fat cuts of meat, lower fat versions of common foodstuffs, eating more whole-grain foods such as bread, pasta and potato and eating more fruit and vegetables.

People should also drink enough water before, during and after exercise to prevent dehydration.

Warming up and down is also important.

Mr Ellis said: "A warm-up gradually adjusts your body to exercise, making it less prone to injury.

"After you've finished your exercise, a warm-down will remove waste products such as lactic acid from your system, gradually lower your heart rate, and help prevent muscle soreness."

A warm-up and warmdown should involve stretching and light aerobic exercise such as a gentle jog.

All kinds of running will improve the heart and lungs.

It can be done very slowly (jogging) or at an all-out sprint.

Sprinting is an anaerobic activity and requires a great deal of power output from the muscles, whereas long distance running is an aerobic activity and requires a lot of muscular endurance.

Running is a high impact activity and therefore may maintain or increase bone density helping to offset osteoporosis.

However, because it is high impact, it puts more stress on the joints than low-impact activities such as walking, swimming and cycling.

Running is available to everyone as long as they are healthy and start out gently and build up gradually.

If a person has a history of diabetes, chest pain, angina, asthma, epilepsy, high blood pressure, have had recent surgery, or you are pregnant then they should consult their GP first.

Beginners who are new to exercise can also look for an aerobics class suitable for their level of fitness and expertise. The club or the instructor will be able to advise on this.

For further details go to www.bupa.co.uk/running.

A GOOD RUN: The health benefits of running are numerous but be sure to approach the activity sensibly