Dog stiff after long walk - normal or possible arthritis?

[Girraffeopottamus]

My lovely dog is a 6 year old, lab cross. In good shape, gets generally between 1- 2 hours a day exercise, mostly off lead. Sometimes longer if we have a day out somewhere dog friendly.
Went on a longer hike at the weekend, about 11 miles. She seemed fine on the walk, happy, tail up, sniffing about, lively and engaged. But after a snooze once we got home, she seemed stiff in her legs. Not to the point that it really bothered her as far as I could tell, but she was plodding awkwardly around the house.

She's fine now - was back to normal within 24 hours. But I'm worried - do you think we just overdid it walking further than she'd used to (I was also rather stiff and achy to be fair!). Or could it be an early sign of something worse like arthritis?
I was planning to start doing longer hikes more regularly, but now questioning whether this is ok/how to build it up so it's not too much for her? Any suggestions or advice much appreciated!

11 miles is quite a lot if she's not used to it.

I would get her checked over at the vets and they'll likely suggest some anti-inflammatory medication. There are also lots of supplements you can give if it's arthritis.

Was she snoozing on the floor, or does she kip on a proper bed? Our arthritic collie tends to scratch up any rug or single layer bed we previously used, so we've now got a couple of Tuffie's beds and they seem to be much kinder when she crashes after longer walks she does prefer to lie on them.

11 miles is an awful lot if she's not used to it. Even quick walkers (like me) only manage about 4 miles in an hour...so if she's only getting 1-2 hours a day she's probably not doing more than 6-7 miles (realistically). This walk was a lot more.

I agree with a PP about taking her to the vets if she's still a bit stiff today. But I would also recommend not over-doing the walking.

Remember: just because a dog can walk that far once in a blue moon, it doesn't mean it should.

Thanks everyone. I naively thought that if she could do 7 miles easily 11 wouldn't be too much of a jump. Lesson learnt and she's fine and back to running around as usual now thankfully.
If we did want to do more regular long hikes with her, does anyone have ideas of how to build this up at the right pace so that it's enjoyable for her and she's not straining anything?

Just build up slowly @Girraffeopottamus - and make sure she has plenty of rest too.