I'm actually type 1 diabetic (have been since i was 7yrs) but i don't let this get in the way of me cycling. However it could affect me if it was to have a hypo (low blood sugar) because myself when my bloods low. I get tingiling/shaking hands, tired, hungry, loose concentration and those that don't know if you don't treat it after those warning sings you can end up getting slurred speech, seizures, coma etc... So to avoid this i do less insulin the meal i've had before i cycle and i now i've started to test before cycling (even though it's not the law to unlike in a car i just prefer too. ). It also stops motorists thinking your drunk (as some people do think that according to google.) on the other end if my blood goes to high i personally can get annoyed at pretty much anyone and do stupid stuff so i try to avoid getting high incase i did something stupid or got cross at a stupid driver etc... (Type 1 diabeties is a auto immune disease which attack the cells in the pancreas so therefor you can't produce any insulin. So i always have to test my blood and do insulin injections every time i eat and at bedtime Feel free to share if you have any medical conditions?