My puppy was just being naughty and for various reasons I can't get him out for a walk right now.

So I partially shredded a carrier bag and with it and a 3.5' stick and some string I made a lure.

He absolutely LOVED IT. So I just want to check...

Is it okay for him to play this way? I limited him to 5 minutes, played on the level bit of lawn and didn't have many fast direction changes (so mostly he ran around me, circle about 10-12 foot diameter, or in an oval while I also ran up and down), and I kept it low (so no acrobat leaping). I also let him catch it quite often.

I don't want to injure his joints or put him at risk but I am always on the lookout for games he enjoys that tire him out. We do also play find it, hide and seek and do training but variety is the spice of life...

It's not really recommended until at least 12 months especially with a large breed.  I think that no matter how careful you are, both of you can get carried away with the excitement - I know me and mine do

What you've described is a "flirt pole". I've made one with strong corded elastic rather than string. If they grab it unexpectedly it won't jarr the neck if they tug away from you like it would with string. You can use it as a restraint training tool. They have to sit and wait for the command before chasing and learn to let go on command before starting the game again. I'd keep it on the ground to chase so his paws never leave the ground, once he's older you can introduce jumping. Look on YouTube at flirt pole for how to make and game / training ideas.

It is a flirt pole!  And i happen to have a load of elastic which would work fine as string!  I will get on YouTube, thanks.