Brain hacking, does chess sharpen the mind?

I've been promoted and want to sharpen my wits. Can anyone with experience let me know does speed chess help us to be sharp or is it better to stick to a longer period game. Also has anyone got anyother ideas how to get the Brain performing to its max?

I'm no master but I would reccomend 5 or 10 minute games. Enough time to think but you still have to manage your time.

Thanks, Sir. Any other tips?

Not really, I'm pretty sure you know or have heard it all.

I found that lots of mackerel and caffeine both help my brain function more effectively. I guess there must be lots of things people find helpful? I know it's a big industry now, this brain improvement programme.