More than a quarter of elite footballers, screened from top clubs across England, have exercise-induced asthma (EIA), a study has found.

Researchers at the British Thoracic Society’s Winter Meeting in London were to call for all top clubs to implement a lung health screening programme to help identify those with airway problems and treat them appropriately.

The study, which was the first of its kind in scope and scale, was jointly conducted by the University of Kent and the Royal Brompton Hospital, London, and assessed the airway health and impact of treatment in 97 elite male footballers undergoing pre-season fitness and medical screening.

It found 27 players (28 per cent of the sample) demonstrated airway problems by giving a positive result in a breathing challenge, which tested for exercise-induced asthma. Of these, 10 (37 per cent) reported no previous history of asthma or airway problems.

Affected players were treated with medication to help reduce any inflammation and narrowing of the airways to increase airflow through the lungs and a follow-up assessment demonstrated reduced airway inflammation and improved lung function on testing.

In a small number of players who also completed exercise tests, those treated for previously undetected asthma also showed a greater increase in their maximum exercise capacity than the rest of the sample.

Researchers said high rates of EIA are consistently reported in elite endurance athletes – but this was the largest study to find this in elite-level footballers.

Study has shown a high level of airway problems which had not been formally diagnosed before – because you can’t always predict them from symptoms alone

The reason why this condition occurs is not fully understood and needs further study but EIA appears to be more common in athletes exercising regularly at high levels of breathing.

Environmental issues such as cold (sometimes damp) air, air pollution and grass pollen may also contribute to EIA development in this population.

Anna Jackson, of the School of Sport and Exercise Sciences at the University of Kent, said: “Footballers who are very short of breath or who cough a lot after training may be deemed as not being 'fit enough', when in fact they may have problems with their airways that need to be treated.

“Our study has shown a high level of airway problems which had not been formally diagnosed before – because you can’t always predict them from symptoms alone, and players may not report symptoms, believing them to be a normal response to working hard.

“The good news is that when these breathing problems are identified, they can be treated helping both the lung function and physical performance of players.

“Footballers are rightly screened for potential heart problems using rigorous medical tests – and we feel that this should also be the case for lung and breathing issues.

“This may increase player performance and help to prevent any more serious problems further down the line.”