When my heart rate is higher than expected: 

Damn this stupid heart rate monitor!
When my heart rate is lower than expected: 

 Wow, I'm in amazing shape!
		
 
		
	 
Example:
Yesterday: 7:16/124 Today: 7:46/137
		
 
		
	 
I hear you, I have been going through a minor crisis of confidence myself in this area, but I don’t put much weight in individual runs. I didn’t have a great start to the year with training, a combination of being a little burned out and coaching my son’s basketball team. Sometime during this training lull, I scheduled my colonoscopy and the first appointment available was the Monday before Broad Street (yesterday), figuring that I wouldn’t be in real racing shape anyway. The colonoscopy went fine with good results.
Anyway, training went better than expected in March being 8 sec/mile more efficient than last March and only 1 sec/mile less efficient than last April. I figured I’d just continue with what I was doing, similar to last year, and I would have a good chance at sub 60 again.
April numbers so far are 8 sec/mile less efficient than March and 9 sec/mile less efficient than April of 2022. I can’t explain why my numbers have gotten worse, my allergies were bad starting the week 4/3, but the past week and a half they haven’t been bad. I feel fine, weight and diet have been good, tempo runs have been fine (not easy but not brutal either). The good news is that my tempo runs and long runs have been efficient, it’s mostly my recovery runs that have been out of whack. It is normal for my recovery runs to be less efficient as they are usually after harder efforts but this is more extreme than usual.
Looking at my 15 day moving average it looks like I peaked this year the days between 3/17-4/1, and last year it was closer to race day 4/7-4/22 without dropping off much before race day. Just another example of once you think you have something figured out you realize you don't.
What am going to do with information, nothing as I’m going for sub 60. If I perform much worse than last year I guess I can say that there were some warning signs. The good news is that it should be raining all weekend so I shouldn’t have much of issue with allergies. Just have to remember to protect the nips. Not sure if the colonoscopy will impact things, I felt sluggish this morning.