Supplement with creatine to improve skill execution in sport training when you are tired. You’ll also raise testosterone levels and lower cortisol, according to new research published in the Journal of the International Society of Sports Nutrition. The study tested the effect of taking either a placebo or a dose of creatine or caffeine on skill execution by rugby players who were sleep deprived. The study tested all players in a sleep deprived and non-sleep deprived state when taking the different supplements. Skill performance decreased after sleep deprivation, but the decrease was significantly less after taking creatine.
Sleep deprived players performed better on skilled passing tests after taking both the creatine supplement and the caffeine supplement than the placebo trial (creatine was most effective). Two different doses were tested for both supplements: 50 mg/kg and a 100 mg/kg for the creatine group and 1 mg/kg and 5 mg/kg for the caffeine group. The 100 mg/kg creatine amount resulted in a better skill performance than the 50 mg/kg dose, a difference that wasn’t seen between the two caffeine doses (which were equal). Additionally, the low creatine dose resulted in slightly better skill performance than both caffeine doses (not a statistically significant difference) and the large creatine dose elicited significantly greater skill execution than all other groups.
Researchers suggest creatine was so effective because sleep deprivation results in reduced brain stores of phosphocreatine, leading to a cognitive deficit and impaired skill performance. The creatine supplement replenished those stores and also resulted in significantly greater testosterone levels prior to the skill tests. Cortisol levels in the 100 mg/kg creatine group were lower than the placebo and both caffeine groups prior to skill tests as well. The 1mg/kg caffeine group had a small cortisol increase, while the larger caffeine supplement group had a significant increase in cortisol.
Creatine is clearly you’re your best to improve performance when tired. And we know it can improve high-intensity training, allowing you to get faster, stronger and train longer. Take note that minimizing elevation of cortisol levels is important because sleep deprivation already increases cortisol, which can lead to anxiety, while higher levels impede the anabolic process.
Cook, C., Crewther, B., Kilduff, L., Drawer, S., Gaviglio, C. Skill execution and Sleep Deprivation: Effects of Acute Caffeine or Creatine Supplementation. Journal of the International Society of Sports Nutrition. Feb. 2011. 8(2).