Jeremy Laurance: Mild uppers and downers unlikely to explain lacklustre performance next day

Caffeine is the world's most widely used performance-enhancing drug. Sportsmen and women use it, students use it, long-distance drivers use it. "Nature's stimulant" improves short-term memory, boosts muscle power and increases alertness. An average cup of filter coffee contains 100mg of caffeine and millions are drunk each day. It is also in tea, cola and chocolate.

The England team could have opted for a strong sup of coffee before the original Poland match on Tuesday. Instead, some are said to have taken ProPlus pills, which contain 50mg of caffeine each. The instructions say take one or two with water and no more than two in any hour – but users tend to ignore instructions. As every coffee drinker knows, a strong brew drunk in the evening is liable to disturb sleep. The same goes for ProPlus pills. If the England footballers had played and ended their game as scheduled at 10pm there would have been no harm done. With them fired up after the match and adrenalin levels high, sleep would probably have been a distant prospect anyway.

With the game postponed but the caffeine already surging round their system, at least one player apparently turned to sleeping pills to come down again. The combination is unlikely to have done any harm – some clubbers enjoy its zombie effect – but it is not to be recommended on a regular basis.

Could this have explained the lacklustre showing the following day? Unlikely. Chronic lack of sleep does damage performance but a single bad night would be unlikely to do so.

Modern sleeping pills have a short half-life – meaning they are rapidly metabolised by the body, leaving no after-effects next morning. In older people there may be a hangover but young, fit footballers should wake from a pill-induced sleep fresh, alert and ready to go.