Back from altitude training

I spent the last week in the mountains of New Mexico at 7500 feet.  I ran 40.63 miles at an average pace of 8:56 and gained over 3000 feet of elevation in the process.  The thin air was hard on the breathing and the climbing and descents were hard on the legs.  The first 2 days were miserable and I was huffing for breath like when I had just started running.  By the end the breathing was better but my pace was pretty steady.  I mostly just tried to enjoy myself.

We drove through the night on Friday and got home early Saturday.  After sleeping all day Saturday I was ready for a long run on Sunday.  10 miles at 7:42 pace.  It was hot and humid (84 degrees).  The heat seemed worse than the altitude.  My HR hit 180 at the end of the run which is the highest its been since I started running with a HR monitor again.  On the way home I stopped at Jubilee park and did a 1/2 mile down and up a 13% grade hill to keep with my elevation gain theme.

After Monday off, I ran my first track workout today.  3X800 plus 2 X 400 with 400 recovery jogs.

Splits
2:50
2:59
2:56
1:30
1:25

I was not really that pumped for the workout and it was a bit of a struggle.  My breathing was labored and my legs felt pretty dead.  Strava thought it was a good effort though and looking back my HR stayed pretty low never getting over 170 until the very end of the last 400.  I think I'm just a bit tired from my vacation still and maybe am just not accustomed to this type of effort?