My wakeup heart rate was OK this morning

I commented yesterday that I didn't have a lot of energy and had a sluggish run until the last half mile. Another factor that could have contributed to that feeling was lack of sleep. During the past couple of weeks I've been getting about 6 hours of sleep when I need about 7 hours. However, I only had about 5 hours of sleep during Friday night. One of the common results of lack of sleep is an increase in ones wakeup heart rate and a general feeling of diminished energy. I've been forgetting to measure my morning wakeup heart rate, so I don't know if my body was tired when I first got up Saturday morning. I did measure my wakeup heart rate this morning, and it was 52, about 4% above my normal of 50 (I had about 6 1/4 hours of sleep last night). It is likely that my wakeup heart rate would have been close to 52 or 53 yesterday morning, and this means it is unlikely that a tired body was the main contributor to my sluggishness yesterday. I think that my not eating breakfast was likely the main problem (I ran about 1:30 pm). The burst of energy I had during the last half mile was probably from the energy bar I ate about 1 1/2 hours earlier.