Su Lin
It sounds to me like you are having a blood sugar crash and it is affecting your concentration. I get that way sometimes and found that if i have a sportsdrink during training i can regain some of that concentration. remember that caffeine will lower your blood sugar levels, so will excersise. the ginko biloba may help in increasing circulation to the brain but what is missing is the glucose.
of course it could be some pumpernickle deficiancy , that or you are going through early menopause
Be Well,,,TWS
It makes me mad when people say I turned and ran like a scared rabbit. Maybe it was like an angry rabbit, who was going to fight in another fight, away from the first fight.