Does cold weather riding decrease efficiency? I commute to work year round, 7mi each direction, but every winter, my average speed drops and it feels like I am working harder to maintain my speed. It isn't very cold where I live-am temps are usually around 32 deg F, occ down to low 20's. I obviously wear more clothing, big ski gloves, light shell. I carry a couple pound battery for my light. Is it just an additive effect from increased wind resistance and increased weight, or is there something about the cold that makes muscles work less efficiently?