Given the tension that will be filling Barclays Premier League football grounds tomorrow afternoon, now is probably not the time to reveal the latest on the health threats to football managers. The Times has seen the statistics from the League Managers Association (LMA) healthcare programme and it shows that of 114 managers who are or have recently been working, 60 per cent have cholesterol levels so high that they are under increased risk of heart attack, 50 per cent have raised blood sugar levels that put them at risk of diabetes and 40 per cent have dangerously high blood pressure.

As if the names Jock Stein, Joe Kinnear, Barry Fry, Gérard Houllier, Graeme Souness and Johan Cruyff were not proof enough of the connection between the hypertension of football and cardiac risk, another medical report shows that football fans also face increased cardiac risk. The New England Journal of Medicine carried out a study in Germany during the 2006 World Cup finals and discovered that on days of matches involving the Germany team, incidence of cardiac emergencies was 2.66 times the norm. For German males it was 3.26 times above normal levels, for women it was 1.82 times above.

It is easier to understand these statistics when you wire up Sam Allardyce, for instance, to a heart-rate monitor. When Allardyce was manager of Bolton Wanderers, he attended the LMA's healthcare centre at the adidas Wellness Centre in Stockport and found that his maximum heart rate when running hard on a treadmill was 146 beats per minute. He then wore a heart-rate monitor while managing his team from the touchline and after calling the referee a “f***ing disgrace” six times after a sending-off, his heart peaked at 164bpm. Furthermore, his blood pressure on the touchline was similar to his blood pressure when going hell for leather on the treadmill.

The statistics from the Allardyce experience were instrumental in persuading the LMA to incorporate a Fit to Manage programme, paid for by the Barclays Premier League, and it is here that Dorian Dugmore, the director of the programme, has seen the toll that the job takes. A regular heartbeat, at rest, should be 60 to 70bpm; Dugmore has had two managers go in with heartbeats at more than 200bpm.

“Of the current managers, 40 to 50 per cent have cardiovascular risk they need to address,” he said. “If you are under pressure all the time, there's a release of adrenalin that tends to constrict your arteries and pump up your blood pressure and can irritate the heart muscle.

“The problem is, the constant lash of stress; there's a part of your brain called the reticular activating system that almost switches you on permanently. That's when stress becomes very, very dangerous.”

The stress that Dugmore is talking about is the kind that managers say they can never put aside. “Managers tell me that even on holiday they can't relax,” Dugmore said. “I had one come back from a week in Spain and say, ‘I'm supposed to have been on holiday, but my heartbeat's racing.' He came in, we tested him on the treadmill and his heart rate went from very slow in no time to 190 beats.”

There have been occasions when a face-to-face meeting with Dugmore has required direct action. Terry Dolan, the former Hull City and York City manager, thought that he was fit until tests showed his heart racing at 214bpm and an irregular beat, which Dugmore describes as “pretty high risk, something that has to be addressed”. The treatment involved a cardioversion - the electric shock pads that are usually used for restarting an arrested heart.

“You think you can cope with everything in football, but you just don't know,” Dolan said. “I've always been pretty quiet around football. But that night after I saw Dorian, I lay in bed, listening to my heart, thinking, ‘Keep going, you bastard.'”

For Dario Gradi, the Crewe Alexandra technical director, open-heart surgery was required for a calcified aortic valve. “When I used to go up to the back of the stand to do my post-match interviews, I found it would take time because I was out of breath,” he said. “I thought it was my lungs, but they said, ‘No, you've got something wrong with your heart.'”

When Dave Bassett, the former Sheffield United and Wimbledon manager, was put on the heart-rate monitor it was discovered that, when his heart was beating fast, he had an ectopic heartbeat - rogue electrical heartbeat pulses that were “very risky”, according to Dugmore.

Like Mick McCarthy, the Wolverhampton Wanderers manager, Bassett did not require treatment, merely close monitoring. Two years ago a family member of McCarthy required a triple heart bypass, triggered by a heart attack that was caused by dangerous levels of cholesterol. On having his cholesterol checked, McCarthy found that he was significantly above the norm. He has used exercise and diet to bring his levels to within normal limits and is at very low cardiac risk.

Dugmore says that it is impossible to pinpoint the extent to which football has been the cause of McCarthy's and the other cardiac issues listed here. But what he does say is that “football management should carry a health warning - and on the last day of the season more than any other”.