If the human body copes well with short duration fasting, it is not the same for periodic fasting. Even when water intake is allowed, fasting for more than about 12–24 h will generally have negative effects on cognitive and physical performance.
There is little research on the effects on elite athletes competing in challenging environments. Training in the fasted state doesn’t seem to be the best way to induce adaptation of muscles. In international sports events, other strategies to eliminate or minimize any effects must be found as to delay the events in the evening.
In London 2012, ramadan and jewish fast will fall during olympic games. This has led to an increase in understanding the effects of fasting on performance to develop specific strategies. So we could have more scientific data about fasting in the coming years…
Bibliography
Fasting and sport: an introduction. R J Maughan
Br J Sports Med 2010 44: 473-475 doi: 10.1136
