Top of The Hill

I did 35+ minutes (3.83 miles) of hill training last night. It was a tough run considering I had not trained like this for almost two weeks. I could feel that I was not lifting my legs as well as I should. About half way through the run, my HRM watch stop tracking my heart rate. I need to remind myself to replace the battery in the heart rate strap soon or else the HRM may stop working completely.