You must round up your mileage? Just kidding. Of course it is harder to ride in those conditions and your body will benefit or maybe suffer from it. Your buring more calories just trying to stay warm. Did a nice 36 miler the other day. 25 mph wind and my feet felt like they were frostbitten. Should I log it in as a 40 or 50 mile ride, no but I feel better just knowing I'm back home warm and safe after the ride. Additionally come spring I'll be ready to keep up with the big dogs.