Letting 4 year old come running with me at 6.30am?

[Giraffeantics]

Early morning runner. 4 year old wants to start coming with me at 6.30am on his bike. Feels wrong given it is dark and he is so young. Am I being unreasonable if let him join me? I would obviously reduce distance covered and only let him.join occasionally and wear a high vis. He has always been an early riser and is awake by 6am each day. Hm..... help!

But the OP posted asking for opinions?
I know that but that's why the thread is pointless. We don't know the character of her child, the area she lives, whether it's the only time she gets to herself,(although she may have mentioned it in in later posts, I'm not trawling through them)
The only reasonable answer is, if she thinks it's safe and wants to give it a go, go ahead.

@notacooldad OP has only made 2 posts. You can filter for OPs. No trawling needed. But you're right, she hasn't really given enough info for anyone to help on a practical level, more whether it would be a nice thing to do.