I was able to set up a 1 mile loop of trail running at Bryant Lake Regional Park yesterday and completed 4 loops. It was between 35F and 40F degrees and misting. Running in my Vibram FiveFinger KSO's felt really good at this temperature despite my feet quickly getting wet and the ground being muddy and slippery. I am wearing Injinji socks inside the KSO's that certainly help insulate my feet from the cold. I think I will be able to used them successfully down to about 25F as long as I'm not running in snow.
I haven't been timing myself yet on any of my runs, as I don't want the pressure of the clock to affect me re-learning how to run using this new method. I have been able to really relax while I run as well as keep my body straight even on the uphills and downhills. I find that if I think about pushing my hips forward while I run, it helps my form tremendously. It doesn't necessarily feel like I am falling forward, but at the same time, it quickens my cadence and keeps my upper body more upright. When I do this running uphill, it makes the 'attack' a lot easier.
Additional clothing I am wearing for this type of weather.
Bottom Baselayer: Icebreaker Bodyfit 150 Leggings
Bottom Shell: Smartwool Synergy
Top Baselayer: Icebreaker Bodyfit 150 L/S
Top Layer: Icebreaker Crew 260 L/S
Gloves: Black Diamond WindBloc Gloves
Observations of clothing: Smartwool Synergy Pants are just too warm yet at these temps. I should probably go with a midweight Long Underwear under my running shorts. The Gloves were also too warm and I quickly shed these and just carried them.
I am still loving running in my VFF's. They are super comfortable and I find I can maneuver around rocks and other obstacles on the trail easily. I feel there is still much too learn with this new running style, but I am loving it!!