Tired Glutes

[Trekhawk]

I have not managed a lot of riding this year but now as the weather warms up I am getting out a little more.
The strange thing is the first part of my body to feel tired on a ride is my Glutes and I do not remember that ever being the case before. I don't think my Glutes ever felt tired on rides before when I was coming back after a break on the bike. I think it was always my Quads that got tired before any other part of my legs.
Its not really a problem as they are not sore after, it just has me puzzled.
My bike set up has not changed and although I live somewhere new the terrain is pretty similar to where I lived last.....HILLY.

I don't think its a flexibility issue but hey I could be wrong.

As I said I do not have any muscle soreness in that area after riding its just while riding this area seems to get that muscle fatigue feeling first and it seems to stay until the end of the ride. I would say it feels similar to the burn you get at the gym after a big glute work out but it disappears after I get off the bike.

So TE crew have any words of wisdom on why this might be?