Idebenone is of the quinone family, however, it should not be suggested as equivalent to either Ubiquinone or Ubiquinol except perhaps from an oxidation standpoint (it is in fact, a very powerful antioxidant like CoQ10) - however, Idebenone hasn't really been very well studied outside of neurologic disturbances (where it was initial market attempts were made by the pharmaceutical industry and went bust for a reason).
In any event, I will let ergo-log tell the tale of CoQ10 athletic uses (frankly because they have some citations grouped already)...
http://www.ergo-log.com/q10endurance.html
http://www.ergo-log.com/q10muscle.html
http://www.ergo-log.com/q10fat.html (as little as 30mg)
But, I would also like you to take a look at the muscle fiber differential and concentration of type IIs that declines with aging (aging that begins the MINUTE you are born).
http://www.heartflo.com/coq10-resources/HumanAging_Global_Function_Coenzyme_Q10.pdf
Now - to have a significant ERGOGENIC effect, I think the average 200-lb bodybuilder needs about 400 mg of Ubiquinone OR 200 mg of Ubiquinol daily. I haven't even talked about ALL THE HEALTH ASPECTS of the compound...for anyone interested though, you can search CoQ10 and heart failure or CoQ10 and heart attack or CoQ10 and stroke. I think you'd be surprised at what you find.
How about the "silent killer" (hypertension or high blood pressure) - it can lower blood pressure (as suggested in a meta-analysis of like 10 trials I think) of 17 mmHg systolic and 10 mmHg diastolic. So - let's say you have a higher blood pressure of about 140/92; it'd look a lot nicer to say that was 123/82 with little effort (granted, I am SIMPLIFYING this story a LOT but for illustrative sake...it makes huge sense).
Want more health effects: extends life, reduced Parkinsonian tremors (unfortunately 1200 mg per day was ingested which wouldn't be economical in most people's land...but it is interesting - kind of like Lou Gherig's disease responding to 40 MG ... NOT mcg guys ... of Methylcobalamin - a whopping dose...these are conditions that are otherwise debilitating or life-ending). Now, please don't assume this means I suggest taking boatloads of all of these nutrients - it simply hasn't been studied so there is no way to predict what kind of results you'd get in a normal person, BUT given our lifestyle (one that I hope means you are busting your a$$ in the gym daily and you live it to the fullest) - this could be perhaps the SINGLE-MOST important element you could take from so many different levels.
I hope if I have even convinced one of you to start that it will mean something - it's not going to be instantaneous (like say a stimulant)...but give it three months and next to a baby aspirin...it may be the single-most beneficial thing you could do for yourself.
D_