Summer is the time of year when many people become more active and take up a new fitness regime, but the risk of injury may be high unless people take preventative steps.

According to Dr William Levine, chief of sports medicine at New York-Presbyterian Hospital, it is important to prevent injuries before they happen by starting off slow.

Dr Levine says that people returning to racquet sports, such as squash, should not expect to be in the same playing condition as they were last year, even if they have managed to maintain their overall fitness over the winter.

"New activities require muscles and joints to respond in a different way. This may result in minor soreness while your body adjusts. If you push yourself too hard too soon, that minor soreness could turn into something more serious," he warned.

The expert also emphasised the importance of warming up, pointing out that the muscles need a chance to go through the motions and get the blood pumping before the actual activity begins, and stretching properly at the end of the activity.

"The single most important thing you can do is pay attention to your body," he concluded.

"Don't ignore the little aches and pains in the joints and muscles. They are early signals that could help you prevent more serious injuries."

Employers should encourage their workers to improve their fitness, experts have said.

New guidance from the National Institute for Health and Clinical Excellence (Nice) suggests that employers should encourage physical activity as this will improve workers' overall health and reduce absenteeism.

According to Nice, the average worker does not do enough exercise to benefit their health and this contributes to sickness absence and decreased productivity, costing an estimated £8.2 billion a year in England.

Exercise can also help to prevent obesity, heart disease, diabetes and some cancers, so Nice is advising companies to encourage employees to walk or cycle to work and use stairs instead of lifts.

Dr Matt Kearney, a GP and member of the institute's Public Health Interventions Advisory Committee, commented: "Physically active employees are less likely to suffer from major health problems, less likely to take sickness leave and less likely to have an accident at work.

"The guidance will help improve employees' activity levels and reduce the time and money lost due to sickness absence. This guidance is good news for employers and employees alike."