Racing at elevation and BP

So I went to Idaho from Va over the weekend and raced in the Lyle Pearson 200 road race. It is a relay and we were Team Sea Level. The race went (goes) from Boise to Ketchum, via Stanley. Spectacular country, lots of elevation and climbing.

I bonked out of the blue on the 4th of 5 legs I was doing, about mile 72. I have mild high blood pressure and on long days/rides/runs and long race days (Half IM or more) I do not take the BP med which is a mild diuretic, in order to retain fluids.

From the first leg of the race my HR was elevated which I attributed to elevation and not being acclimatized, but my perceived effort was through the roof all day. In short, I felt like crap. Anyway, pulled it together and pulled a strong leg of 25 miles, then- bang. I was cooked.

I understand this could be attributable to many factors converging: travel, training fatigue, elevation, nutrition, but this felt different. I wanted to push, to work my legs and there was just nothing there, but not from having really stressed them. It was more a feeling that I couldn’t get air to the engine. And in my recovery I have not had any leg soreness, just overall fatigue.

As BP meds are a vasco dialator and aids blood (oxygen) to the muscles, I wonder if laying off the med, especially at elevation, is what scewed me. I feel as though I used only half my engine (lungs) and not my legs.

Or maybe I just did what my overall fitness level allowed me to do that day in those conditions.

Does any of this resonate with anybody?

Can’t really comment on the BP meds, but could be travel or stress or set-up. Altitude can’t help. If this continues to happen, race rehearsals or other hard efforts, start playing around with hydration, meds etc.
Good luck with it. That sounds like a way cool race!