However, quantifying an effect in a team sport can be difficult. The repeated passing skill test we described herein is simple to perform, has sport-specific relevance and appears to be highly reliable across repeat testing. It is not however a one off, high-level MAPK inhibitor MS-275 in vivo performance task, rather a repeat of 20 fairly simple tasks, alternating passing sides. While we don’t claim it to be in any way, yet, a valid performance measure it did reveal some interesting differences across acute sleep deprivation and across caffeine and creatine treatments. In line with observations in other skill and psychomotor testing acute sleep deprivation reduced the accuracy over repeated trials. There

was a general trend to a drop-off in accuracy latter in the repeats (second 10 of the 20 repeats). Whether this is a greater susceptibility to mental fatigue or not remains an interesting question, as does whether single skill repeats separated by more recovery time or by a similar physical activity with no real skill requirement would show a deficit in performance or not. In non-sport related psychomotor trials there is little evidence that a single episode

of sleep deprivation produces significant deficit in a single task [15]; however across repeat tasks it is perceived that much greater 3-deazaneplanocin A manufacturer effort is needed to maintain concentration [24]. Acute sleep deprivation has little effect on weightlifting performance [20], but can influence mood negatively [24] which may be a driving feature in mental performance changes. Caffeine, for example, has been shown to improve both mood and mental function following sleep deprivation [25]. It is not known how much mood and other cognitive function, particularly motivation Selleckchem Hydroxychloroquine on repeat skill tasks, interact. At the doses and administration time of caffeine use in this study we saw no evidence of an effect in non-sleep deprived subjects; however, there was a clear amelioration of skill performance deficit from the sleep-deprived trials with placebo administration. The psychostimulant effects of

caffeine appear to be related to the pre and post synaptic brakes that adenosine imposes on dopaminergic neurotransmission by acting on different adenosine receptor heteromers [26], although numerous mechanisms are likely to be involved. We did not see a dose related effect with caffeine supplementation, with 1 mg/kg and 5 mg/kg producing similar effects, nor did we see high individual variance (i.e. responders and non-responders). The absorption of caffeine in plasma following consumption has been estimated at between 30 and 90 min with half life of several hours [16], so the time between consumption and testing (90 min) in this study may have been too long to see all effects of differing caffeine dose, or any effect on non-sleep deprived performance.