Rather, the opposite is true. The more sex enjoyed before stepping on to the track or pitch, the higher will be the levels of testosterone, and with it aggression. And the good news for female athletes is that the researchers believe the beneficial effects of pre-match sex will apply just as much to them as to the males.
If the scientific findings are true, it will mean not only a drastic change of routine for footballers on Friday nights - no more carpet bowls or card games in the foyer of their Stakis hotel - but that much of sporting history will have to be rewritten.
All the great performances of the century will no longer be analysed in terms of prevailing conditions, or technique, or even luck. It may all come down to whose company an athlete shared the night before his great achievement.
Already, the search will be on for anyone closely involved with long jumper Bob Beamon, who leapt more than 29ft at the 1968 Mexico Olympics. At the time, his remarkable jump was put down to the thinner atmosphere at the city's high altitude. Now we may have to start looking lower for the real reason he jumped into history.
Throughout the century, most coaches have stuck to the disciplined line of no sex and an early night for the players. The most fanatical puritans have usually been found among the ranks of boxing trainers, Scottish football managers and American football coaches, for whom training camps with no entertainment, no alcohol and certainly no concubines were the order of the day.
Mike Ditka, a former coach of the Chicago Bears, announced a curfew before the 1986 Superbowl by saying: "You can only play this game once. If wives and girlfriends can't wait, tell them to take a cold shower."
Bill Shankly, the great Liverpool manager, was certainly of the view that women should be at the back of footballers' minds throughout a season, not just on the nights before games. He was rumoured to have got married during the close season, but then to have honeymooned by taking his wife to watch a reserve game.
However, the theory will come under close scrutiny in Israel - two weeks ago its international football team apparently sneaked their wives and girlfriends into their hotel the night before the Euro 2000 play-off game with Denmark. The Danes won 5-0.