Loss of acceleration power

I put a lot of miles on this vehicle, I do lots of desert driving. I've always maintained it and checked fluid levels. I try and do as much of the work myself that I can on her, but I lack most knowledge on the mechanics regardless. That being said, I do drive it kind of on the fast side, and I know it's wear and tear. Last week I noticed a slight studder or two as I was normal street driving, during acceleration. Enough to really notice when I felt it a couple times. I just did a long drive, and while at highway speeds, it did it again more consistently. I think I was going probably 80. It feels like it's puffing air, or shuddering. Especially on incline. It did not feel powerful at all. It doesn't ever shut off on me. Nothing major. But after that. I babied it and it continued on fine. No check engine light. No stalling. Idles in park around 600, sometimes feels a bit on the frumpy side of idling. But my acceleration just isn't what it should be.