New study suggests you might not want to race after 30 hours awake.

Researchers from Bangor University in Great Britain recently performed an experiment on the effects of sleep deprivation on running performance that must not have been terribly pleasant to participate in. On two occasions, eleven male subjects completed a test consisting of 60 minutes of treadmill running at a moderate pace followed immediately by a 30-minute time trial.The night before one of these tests the subjects got their normal amount of sleep (8 hours and 16 minutes, on average). On the other occasion, the subjects completed the test after being awake of 30 hours.

Not surprisingly, distance covered in the 30-minute time trial was significantly less after sleep deprivation (5674 to 6773m) than after a good night’s sleep (6037 to 6547m). Interestingly, however, there was no effect of sleep deprivation on how difficult the running test felt. The authors of the study, which was published in the European Journal of Applied Physiology, wrote, “In conclusion, one night of sleep deprivation decreased endurance performance with limited effect on pacing, cardio-respiratory or thermoregulatory function. Despite running less distance after sleep deprivation compared with control, participants’ perception of effort was similar indicating that altered perception of effort may account for decreased endurance performance after a night without sleep.”

The lesson is clear: If you need an excuse for a poor performance in a race, claim to have not slept a wink the night before.

For More: PubMed Abstract