Was altitude training behind England's World Cup flop?Too long spent training at altitude can impair performance
Many reasons have been given for England's poor performance at the 2010 World Cup, but a new study has pointed toward an unexpected explanation - the time spent training at altitude before the tournament.
Altitude training is considered important for athletes because as height increases above sea level the air becomes thinner and carries less oxygen - making physical activity harder.
Most of the World Cup games were played above sea level, with England's opening game against the USA taking place at 1,500m. Prior to the competition England prepared in the Swiss Alps to help acclimatize themselves to the lack of oxygen. But some teams such as the USA chose not to train at altitude.
Now scientists studying a rare genetic condition have found that conventional wisdom regarding altitude training may be wrong - too much training in low oxygen conditions could actually impair performance.
About the study
Scientists at Oxford University studied people with a genetic condition (Chuvash polycythemia or CP) which produces high levels of a protein called hypoxia-inducible factor (HIF). This protein is central to the body’s ability to respond to high altitudes. CP is so rare that there are only 20 sufferers in the UK.
When the body exerts itself in low oxygen conditions, it starts by breathing harder and pumping more blood. It produces more red blood cells and increases the density of blood vessels in the muscles. But extended exposure to these conditions can result in a loss of the muscle's ability to use oxygen to do work. HIF plays a major part in controlling these responses.
The team compared the performance of five people with CP with five matched controls. In an exercise bike test, in which study participants were asked to keep a constant pedal rate against a steadily increasing resistance, those with CP had to stop exercising earlier. The maximum work rate they achieved for their weight was 30 per cent less than controls.
Studies of metabolites present in calf muscles under light exercise also indicated that CP patients experienced greater fatigue. Finally, there were differences in expression of metabolic genes in the CP patients' muscles. This could suggest their metabolism makes less efficient use of the fuel available and may explain their reduced exercise capacity.
Commenting on the results, study leader Dr Federico Formenti said: "We found that the metabolism of CP patients is different and leads to poorer physical performance and endurance."
Although only a small study, the results were striking. Further study could lead to better treatments for people with conditions where oxygen supply in the body is limited, such as heart disease and cancer.
Implications for athletes
The study suggests that too much training at altitude could affect the metabolism of the body in a negative way if these results apply in this case.
"There may be an optimum time for athletes to train at altitude," Dr Formenti suggested. "More work is needed to find out how long athletes should spend at low oxygen levels to get the most benefit."
As for the England team's performance, Dr Formenti thinks that the time they spent training at altitude was probably not long enough to adversely affect their performance - so that is another excuse they can't use!
The study is published in the journal PNAS and was funded by the British Heart Foundation and the Wellcome Trust.
This article was published on Wed 14 July 2010
Image © Walter Luger - Fotolia.com
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