Benny and I have been out in the yard this morning, I put our thermometer in the sun just to see how warm it is today... this is at 8200 ft. altitude in early March! I bet it'll be 80 by the afternoon.. granted this is in the sun, but we've been out in the sun.
Last Tuesday I ran 10 miles in 1:07 with an average HR of 142.
Today- same course (with the same 1500+ feet of climbing) I ran 1:06:32 with an average HR of 152. Technically- 10 beats higher HR means that this test was worse than last week, the "improvement" in pace was not significantly better but the HR was significantly higher. This test does not mean I have lost fitness nor does it indicate that I have stayed the same.. what I see from this is that I am fatigued (along with other factors listed below). Effective training should make you weaker and broken down, so a test of this sort has little benefit unless you use it to gauge fatigue. The most effective tests are after a rest period. I often see athletes disappointed after a poor test result, but if you keep it in perspective, a poor test result can be a great thing. It can show you that you are training hard enough to elicit fitness gains, and also that it's time to back off a bit and unload fatigue (the two go hand in hand). This is where the HR monitor is a useful tool and should be implemented. It's even easier to perform a short test on a Computrainer or if you have a power meter on the bike. On a set day each week where you have a bike workout- you can compare HR VS. wattage at the end of a 20:00 warm-up to see how your body is responding. Low wattage and high HR is a sign, so is a depressed HR and a high PE.
My PE was higher towards the end of today than it was during last week's run. Another sign of fatigue. I also slipped on hydration this morning as I woke up a little late (5:45) and made the choice to drink coffee and not water. And yet another factor could have been the unusually warm temperature.. I could have worn shorts this morning! Crazy hot during the run. The results of the test don't alarm me much at all. HR 152 is still ~25 beats below my LT, still quite aerobic.