For the first half of my run, those incessant little buggers were out in full force, and they weren't just swarming, they were biting as well. This forced me to pick up the pace, giving me a good tempo workout on some technical trails. I was also flapping my arms the entire time waving them out of my face, getting a great upper body workout. This was aided by the hand-held water bottle I was carrying (think dumbell).
I drew a picture to better illustrate this concept:
Ran 7.3 miles @ 8:25/mile pace.
AHR/MHR - 152/168
Trails, fire roads.
Very hilly.
Upper 70s falling to lower 70s, extremely humid, partly cloudy and then thunderstorms.
Shorts, short sleeved shirt, cap.
Deer flies killed = ~28-34
Deer fly bites = ~15-18
Deer flies flying into mouth = 3 (one down my throat)