Raul on a 25,000ft high after installing oxygen room to extend career

It's not quite being "over the moon" but the Real Madrid captain Raul has been sleeping at altitudes of up to 25,000 feet in order to turn back the effects of ageing and fatigue on his tired limbs.

The 30-year-old striker, who travels to Germany today with the Real Madrid squad ahead of tomorrow's Champions League tie with Werder Bremen has been sleeping in a special oxygen room which simulates conditions of altitude in order to boost his endurance levels.

The technique was originally favoured by cyclists preparing for mountain climbs, and marathon runners such as Paula Radcliffe are also believed to have used the method.

In the past sportsmen and women have put themselves in specially designed tents but Raul has gone a step further and has a specially designed room in his house.

The room has a revolutionary air-conditioning system which pumps out air containing lower than normal levels of oxygen and slighter higher than normal levels of nitrogen. The result is an increase in red blood cells meaning oxygen reaches the muscles more quickly, delaying fatigue and speeding a player's recovery.

This season Raul has played more minutes and has been rotated less than any other outfield player at Madrid, apart from Sergio Ramos who is almost 10 years his junior.

Medical experts say the method is safe providing the altitude simulated is not more than 30,000ft and it is also legal, although a spokesman for the newspaper ABC that first reported the innovation told The Independent that the player, believed to be the only professional to have such a room, had been reluctant to reveal too many details.

It is understood Raul spends one or two nights a week in the conditions, but that there is no mobile room for him to use prior to away games.