Abstract
The present study examined the effect of partial sleep deprivation (PSD) and racial variation on muscle power and fatigue during a 30-s Wingate test. In randomized order, 36 healthy football players - 12 black Tunisians (BT), 12 white Tunisians (WT) and 12 South Africans (SA) were asked to perform a 30-s Wingate test during which the peak (PP) and mean (MP) powers and the fatigue index (FI) were assessed. Measurements were performed in the afternoon after two nocturnal regimens: (i) a reference normal sleep night (RN) and (ii) 4-h of PSD caused by an early awakening (bed time: from 22:30 to 03:00 h). Our results showed that PP and MP were higher in SA than WT and BT during the RN control. Likewise, compared to this control, PP and MP were affected by PSD during the following afternoon in SA. There was a significantly greater decrease in PP and MP (p < 0.001) after the PSD in SA group compared with BT (p < 0.05) and WT (p < 0.05), values for SA, WT and BT now no longer being significantly different. However, no major difference was observed between WT and BT in regards to all parameters. Also, FI was unaffected by either sleep deprivation or racial variation. In conclusion, our results show that 4-h of PSD at the end of the night affect performance during the Wingate test at 18:00 h more in SA than Tunisians. These results suggest a greater vulnerability of SA to sleep deprivation. These results may help to guide athletes and contribute to public health recommendations for competitive events between different athletes of different ethnicity.