The agony and the ecstasy

Runners in Sunday's London Marathon will have to overcome huge physical pain. But, says Henry Nicholls, emotional trauma is as much of an obstacle

When the Greek messenger Pheidippides became the first person to run a marathon in 490BC, he reached the end of his gruelling 26-mile run, delivered his message, keeled over and died. But before he ran himself into the ground, how did he feel about his achievement? On the basis of research into emotions experienced by marathon runners, Andrew Lane, professor of sports psychology at the University of Wolverhampton, is prepared to hazard a guess. "Seeing that finishing-line, there'd be a huge anticipated sense of happiness," he says. And this Sunday, when some 33,000 runners stream through the streets of the capital in the 24th London Marathon, there will be such emotional highs. But there will certainly also be emotional lows, he warns.

For several years, Professor Lane has been recording how people cope with physically demanding exercise, and what better place to conduct his research than in Greenwich Park, where runners will gather this weekend to begin the London Marathon, while the rest of the nation is drawn to the TV and wonders why they bother. At last year's London Marathon, he asked a random sample of runners how they felt before the race. Of the range of emotions they could choose from on his questionnaire, there is one, perhaps unsurprisingly, that comes up more often than anything else - anxiety.

Professor Lane says, however, that this emotion can have very different effects. "Anxiety is motivational when it is coupled with feelings of excitement and calmness," he says. "By contrast, anxiety is harmful when it is coupled with an emotional profile characterised by feeling depressed, tense, tired and confused." More than a third of those interviewed matched this more damaging profile.

Professor Lane met the same runners at the finishing-line to ask them about their experiences during the run. Intriguingly, he says, those who expressed anxiety and negative emotions before the race reported "hitting the wall", an experience typified by feelings of anger, fatigue, depression and confusion. Those runners who had been anxious but excited at the start also said they experienced extreme tiredness at the hardest part of the race, but were able to turn this into a positive experience that was part of the challenge. His conclusions: "Exercise is a highly unpleasant experience if you're not trained for it."

One consequence of this is that a large proportion of those who enter a marathon never want to do physical exercise again. In an increasingly sedentary world, this is an irony that motivates Professor Lane's research. So, for anyone entering the race, he has some tactical advice that should make the day more enjoyable - and hopefully engender a long-term love of exercise (see box, right).

In the marathon-research arena, Professor Lane is working alongside Greg White, research manager at the English Institute of Sport in Manchester. While Professor Lane is looking at the thoughts and feelings of the runners, White is interested in the physiological changes that occur in the body following such strenuous exercise. In particular, his research focuses on the effect of ultra-endurance events on the structure and function of heart muscle. During the previous two London Marathons, White collected data from entrants immediately before and after the race and then again 24 hours later, and he will be doing it all again this weekend. His subjects are all "recreational runners", taking between three and seven hours to get round.

White measures their heart structure by taking an electrocardiogram (ECG). This measures the electrical activity of the heart, and has shown that at the end of the race the heart muscle is more relaxed than it is in trained athletes. "Immediately after marathon running in recreational runners there is a depression in function," says White. In addition, blood samples taken from these volunteers at the finishing-line contain a protein called troponin that is involved in muscle contraction, which has somehow leached out of the heart tissue. "This suggests that there is some ongoing damage to the heart muscle," he says, "but the levels that we see are relatively low and 24 hours later the troponin has been cleared from the blood completely."

Nevertheless, there is a clear difference in the response of the heart between very fit and less fit individuals. "This reduction in heart function and the presence of troponins in the blood is more prevalent in the lower-trained individuals," says White. This shows the necessity of appropriate training before a marathon to help the heart adapt to the stresses the race imposes.

White has made another observation about a lot of the recreational runners clocking in times between three and seven hours. They seem to see-saw between walking and running in a cyclical pattern that he calls the "walk-jog programme". The data suggests that this start-stop pattern shown by slower runners could have something to do with body temperature. "Core temperature rises to this critical level," argues White, "at which point the body tells them to slow down or stop, and when they move into a walk, temperature drops off and they then start to run again."

On top of wild fluctuations in temperature, runners must also contend with the relentless depletion of glycogen reserves that are powering their muscles. This is where White's research joins hands with Professor Lane's work on mood. Glycogen is the brain's main fuel, and without it the brain quickly packs up. So it's possible that the rapid use of glycogen in muscle tissue starts to have an effect on brain function, and this could explain the fatigue experienced by most runners towards the end of a long race such as the marathon.

Indeed, this mutual dependence of both the brain and the muscles on glycogen may be the body's way of ensuring that levels do not drop too low. An overwhelming sense of fatigue usually stops further exercise pretty quickly, thereby avoiding any further glycogen depletion that eventually would cause organ failure. By drinking the high-glucose drinks at stands along the length of a marathon, runners can keep going without risking their glycogen falling to dangerously low levels.

It could be that these two factors - the fluctuations in core body temperature and the depletion of glycogen available to the brain - can explain why some people have such a bad time. "It's probably a combination of those two which may well be having an effect on the mood and emotion of the runner themselves," White suggests.

But as the race reaches its conclusion, any negative emotions begin to be replaced by positive ones. For almost everyone, crossing the line is a highlight of the day. "They know they're going to finish and they start getting cheered up by that sense of achievement," says Professor Lane.

So most of those runners taking part this weekend should come away with the feeling that, after all the emotional and physical pain, it was at the end of it all a fun run.

HOW TO GO THE DISTANCE

Set realistic goals

During training, a large proportion of runners never do a full marathon, so don't appreciate how much they will slow down towards the end of the race. "Do not simply double your half-marathon time," warns Professor Lane. It would be better to do a 20-mile run and use your speed over the last two miles as an indicator of how much you are slowing down. After 24 miles, the last two miles will seem very long. Being realistic gives you a better chance of avoiding the unpleasant emotions that some 40 per cent of runners report.

Take it easy at the start

Try to run the second half of the race at the same pace or preferably faster than you did the first half. The supporters who turn out to cheer on the runners at the London Marathon - half a million, estimate police - make it one of the most well-attended marathons there is. But this can be a hindrance to the runners, because it makes people push themselves harder than they have trained for. When you flag towards the end of the race, it can be intensely demoralising, so go especially slowly during the first half of the race, suggests Professor Lane. If you are planning on a five-hour marathon, you will have a better experience if you take 2 hours 45 minutes over the first half and do the second half in 2 hours 15 minutes. "Running the second half at that speed would involve passing thousands of people who set off too quickly," he says. "The crowds would be cheering and the runner would get a sense that the cheers were for them."

Prepare for the hardest part of the race

"Try to imagine how hard this will be and mentally rehearse coping positively with these sensations," Professor Lane suggests. For many people, the magnitude of the physical struggle is so unexpected that feelings of anger and depression can take over. If this starts to happen, you should have a plan. "This might be to focus on technique, or it might be to hum a song in your head to distract you," he says. "If you have a plan that is prepared and practised, you should be in a better position to cope when the real situation arises."