Artie Fufkin
like to run
Good question. Could be a myriad of reasons. Probably the increased mileage, potential weight loss? Increased confidence will all play a part.
I think getting yourself used to running at certain paces so they end up feeling comfortable is another reason. You should look back on your heart rate and see if it was really more comfortable or just felt like it.
Heart rate is super key I think. Most of my running is done on effort or feel, not pace.
For my "comfortable effort" runs all I have on my Garmin watch screen is time, distance and average heart rate. For those runs, I like to aim to be on or below 140 bpm but it can fluctuate a bit as it's quite hilly where I live so I'm either going up or down. I don't look at my average or lap pace. I don't think there's any need to really.