Cycling after illness

After being out with the flu for a week and out with a cold the week before that (making two weeks without cycling), I was finally better and I couldn't wait to get out on the bike again. I decided to do a 40 mile hill climb to start off again. This was yesterday.

Today, It seems my flu has returned. Did I do too much yesteday effort wise? Does cycling reduce immunity or something?

 

You probably overdid it but don't worry about it. Just wait until your better again, and maybe do something a little easier on the first day to see where you are. Yes, training can affect your immune system.