What the chiffchaff?

My new YouTube hero is SickBiker.  I did my first indoor turbo session for beginners with him today.  I made it as outdoors as possible, facing the garden with the backdoor open.  He got me through 45minutes surprisingly quickly - he even made me laugh!  

He reckons I'll be flying when I'm back outdoors.

I'm not chiffchaffin' sure about that though.