"[Heather MacLean, an Olympic 1,500-meter runner] realized her watch was draining the fun from her runs. It was especially apparent to her during a low-key stretch when she was simply trying to build fitness....
“I]f you’re searching for an elusive BQ, here’s what the data show: slow your runs down, choose your course wisely, shoot for a negative split, and remember that practice makes perfect. It may take a couple of marathons to get it absolutely right, but that experience will be invaluable.”
To be fair I was well rested and since the heatwave is over I didn't have to fight the environment as much (although it rained and I was properly soaked and heavy)....