Am I experiencing a natural slump or overtraining?

[Jenny Lynes]

So, I trained and ran the Painter's half in St. George at the end of January.  I PR'd at 1:41 and felt great! I have never felt so strong in a race.  Unfortunately, the past few weeks everything seems harder.  Going some of the same distances at the pace I was able to do before seems so hard.  I even had trouble feeling like I was getting enough air at the end of yesterday's run.  I am training for the Thanksgiving Point half April 30th and would really like to break 1:40 but lately that seems unlikely.  Am I just wimping out or looking back on previous runs with a golden haze? Or should I lay off my speed a little bit?

[Michelle Lowry]

Jenny,  I have just taken a peek at your last couple of weeks and it does look like you might be overtraining, esp some slow runs and warm up paces seem a little fast.  I use Greg McMillan's running calculator, and when I put in your 1:41 1/2 marathon pr, it says your easy runs s/b around 8:38-9:08 pace.  If you treat the easy runs easy, you give your body recovery time and it can feel more "on" for hard workouts.  The running calculator also gives you appropriate paces for tempos, and conversions for fartlek (1 min pushes s/b 10k pace). 

[Jenny Lynes]

Thank you, Michelle! I hadn't thought of putting my times into a pace calculator.  That makes sense and is actually kind of a relief to me! I definitely think I will back off a little bit on the speed.