In my usual 4.5 mile neighborhood loop, there is a pretty big hill just at the end of the second mile. (Taking a look at the elevation profile on the map, it looks like it is about a 70 foot rise in about a tenth of a mile).
I usually slow down on this hill as my heart rate will normally go up into the low 160s by the time I'm at the top.
Today, I decided it was time to add a little hill work into my routine.
I charged up the hill.
By the time I was at the top, my HR was at 185 bpm - pretty close to my max. When I slowed back down, I could feel the muscles in my legs and glutes telling me that they just had a workout!
Calming things down after that was a bit difficult, but I was able to keep my HR in the low 150s for the most part. I can tell I'm still not 100% back from the blood donation (it's only been a week, previous history tells me it takes about 3 weeks for me) - I felt fine during the run, it's just that my pace is a bit slower at the HR I normally run at. I'm not too worried.
4.47 miles in 49:09 - 11:00/mile pace with avg HR 153, max 185 (at the top of that hill!)