My wakeup HR was 46 this morning and I felt great. I ran 5 miles on the Jordan River Parkway in shade temperatures of the low 80s (F), which means the sun temperature was close to 100 (F). I took 12 ounces of water and about 10 ounces of Gatorade and drank my usual swallow at each half-mile walking break.
During the first mile warm up, I ran a 11:30 mile. Then I ran about 11 minute miles for the next mile and a half. Then, on the way back, I ran 10 minute miles. This means that, according to my new goals, I ran a mile to warm up, and then I ran my recovery LSD pace for a mile and a half. Then I ran my comfortable LSD pace for the remaining 2 1/2 miles. Those statistics show that my warm up was actually more than the first mile. Because of the heat, I don't think I could have maintained the 10 minute pace for another 5 miles like I did on Saturday, but I'm happy with my paces today. A shade temperature of 82-83 (F) is a hot temperature for running a path with little shade, meaning I was running in sun temperatures close to 100 (F). Due to our high mountain elevation (4200 feet along the Parkway), the sun here burns a lot more than it did in New England.
As soon as I started running, I could tell I was stronger than yesterday, because yesterday I took walking breaks about every quarter mile and still felt tired, while today I took them at every half mile and felt great. I just needed that extra day to recover from Saturday's run. Drinking liquids while I ran this morning helped too, I'm sure.