Whether you're helping sports stars or fighting obesity, a postgraduate degree is becoming a requirement, says Heather Walmsley

A banana, at Wimbledon, is a sure sign that a crashing topspin serve is on its way. Lean tennis pros munching this yellow fruit between marathon baseline rallies have secured its place as the ultimate high-energy snack, perfect for endurance sports.

But what if swallowing is a waste of time? The mere taste of a banana could boost sports performance - without any carbohydrate consumption - according to Professor David Jones. This is no Atkins diet evangelist - Jones leads a cutting-edge research project at the School of Sports and Exercise Science, at Birmingham University.

Sports science graduates who dream of working with Olympic athletes, should consider joining him. Postgraduate study is now essential - for anyone serious about a career in this competitive field. There are around 10,000 sports science graduates each year, and far fewer jobs. Specialist expertise is necessary to make it to the top. PhD research - leading to a permanent academic position - is the most heavily trodden track.

Birmingham has one of the very few 6* ratings in the Research Assessment Exercise (RAE) for sports and exercise science. The school offers several PhD scholarships annually, and a fascination with carbs is not a requirement. Potential projects range from studies of spinal stretch reflex responses to investigations of what motivates adults into exercise. Glasgow and Bangor Universities were also top scorers in the last RAE, along with Manchester Metropolitan, Liverpool John Moores and Loughborough.

The joy of an academic sports science career is that it combines a regular salary with opportunities to pursue groundbreaking research, says Dr Claire Palmer, executive officer of the British Association for Sports and Exercise Sciences (BASES). Academia also offers the freedom to dabble in applied work on the side. The British Gymnastic Association, National Ice Skating Association, British Orienteering Federation, British Olympic Association, and the Police Service have all taken advice from staff at Bangor University in the past.

But research is no longer the only way to the top. Regular injections of lottery cash into sport have transformed the employment landscape, according to Palmer. Lucrative positions for sports psychologists and strength conditioning coaches now exist within most elite teams and national sports governing bodies.

Palmer herself worked for 10 years as a sports psychologist and then sports science manager for England Netball. She advised the England team shooters on their pre-shot routine, teaching them to take deep breaths and visualise the perfect shot. "They run around like nutters trying to get the ball and suddenly have to do a very closed controlled skill," she says.

Organisation and administration also made up a hefty chunk of her day. "When athletes go touring for a big competition, about 70 per cent of stress is due to organisational issues: being away from home, boredom, not liking the food," explains Palmer. "I did a lot of work to minimise that stress."

To land a job with a national governing body or team today, graduates need to study for a taught Masters degree first. These typically develop specialist skills in one of three sports science disciplines: biomechanics, physiology and psychology. A few offer a general interdisciplinary approach.

Biomechanics focuses on forces and motion. A specialist might work with tennis pros on their serves, helping them achieve maximum force. Physiology is concerned with physical anatomy and achieving peak physical fitness. Psychology concentrates on the brain, so coaches work to maximise motivation and concentration, and minimise stress - in individuals and teams. The three disciplines are distinct, but must work together: there is little point showing a gymnast how to bend her limbs into the perfect position, if she is neither fit nor confident enough to perform a move.

Choosing a specialism will help you to navigate through the otherwise disorienting maze of Masters degrees on offer. Loughborough, for example, offers nine distinct MSc streams - all of which provide tuition by world-leading experts, according to Professor Stuart Biddle, head of the School of Sports and Exercise Sciences. Manchester Metropolitan offers a straightforward choice of three disciplinary pathways. The three Glasgow universities have teamed up to offer an innovative MSc in medicine and science in sport and exercise. Working professionals can take this part-time, choosing from 12 modules that cost £350 each, totting up course credits over as long as five years.

It is exercise science - not sports science - that will be the lucrative profession of the future, according to Palmer. Exercise science aims to improve the health and fitness of the general population, rather than peak athletic performances. There are only around 200 elite athletes in the UK. But two thirds of the population of England are overweight or obese, costing the NHS between £6.6 and £7.4 billion a year, according to a report by the Health Select Committee.

The Health Secretary, John Reid, is taking this obesity "epidemic" so seriously that he has set up a committee to encourage and enable people to eat more nutritious food and take more exercise. So job prospects for graduates of Bangor's MSc in Applied Exercise Physiology should be good - as more advisory roles are created, in government, the NHS, private healthcare providers and leisure centres.

Whether it's elite sprinters or fat children with whom you dream of working, BASES accreditation underpins professional success. This national quality assurance scheme guarantees practitioner competence. Accreditation only costs £75 but normally requires three years of supervised work experience. Some degrees will help graduates kick-start the process, offering applied work experience and allocating supervisors. It is well worth choosing one that does.

'I've had access to the Olympic swimming team'

When she's not producing coursework for her MSc in sports science, Natalie Dunman can be found by the poolside - measuring the heart rates of Britain's top swimmers. She is one of 10 postgraduate sports science students at Loughborough University to have won a training scholarship with British Swimming, the national governing body for swimming, diving and synchronised swimming.

"We have each been assigned to a coach in the area. We go to their sessions and record timings and heart rates, then come back with suggestions for improvements on the training session," explains Dunman.

Dunman initially studied chemistry and sports science as an undergraduate at Loughborough, but found it tough to find a job armed with just a BSc. She enrolled on a general sports science masters and now dreams of being head of sports science for an elite football or rugby team.

Dunman is currently working on her dissertation project - about talent identification in British swimming.

"I'm measuring a massive number of people," she says. "Through the British Swimming scholarship, I've had access to the Olympic team."