I did a little science experiment at GADV yesterday. They had a blood drive at the park that I participated in, they were offering a free ticket and I haven't made it to GADV this year so I figured why not. Nitro has never given me issues with grey/blackouts and I wanted to see how blood donation would affect it, if at all. Everything was normal until I was re riding, then I was greying out going through the helix which never happens to me before. So moral of the story, if your susceptible to blackouts don't donate blood right before going to the park. Well I guess you didn't need me to tell you that it's pretty obvious, just wanted to share an interesting observation I had that that was relevant.