Thanks for your reply, well explained. I never gave much credence to the craze about B vitamins, but I will have to check it out now
As for caffeine, its not that i try to avoid it but i'm not really a fan of getting too amped up from a supplement. Doesn't seem natural to do that on a consistent basis.
You're welcome.
IMO, the B vitamins are not something to use only on certain days, but are most beneficial when made a regular part of the diet. B-6 is crucial for CNS recovery, but is not something you want to
only take on training days, for example, since your nervous system works nonstop.
You may want to take a milder B-12 supplement routinely to get and keep it in your system, and then use a "mega-dose" like the 5-hr Energy with its other ingredients prior to training. Try it for a few weeks and see if you notice anything.
Also, increasing water intake in the hours leading up to training does wonders for many people. Hydrated muscles have greater output than dehydrated ones. I've made this recommendation to several people. Some act astonished at how well it works.

While on the topic of hydration, some trainers report increased endurance/stamina with glycerol powder, which draws increased amounts of water into the bloodstream for delivery to muscle tissue rather than being lost through perspiration. These mechanisms may help delay the onset of dehydration and fatigue, which could be considered a performance-boosting effect.
Glycerol powder is relatively inexpensive. I bought a canister several months ago, but have not opened it yet - so, no personal feedback at the moment. Sorry.