Gokbel et al 2010 completed an 8 week randomized, double blind, crossover study. 15 healthy sedentary males were given placebo or 100mg of CoQ10 supplementation. The subjects performed 5 wingate tests several times over the 8 weeks.
It was found that those taking the supplement had more power during their fifth and final trial of the wingate test than those taking placebo (p value not published). This would imply that in tasks requiring multiple bouts of maximal efforts (eg: basketball), CoQ10 supplementation can provide an edge in competition.