The weird thing is, I only had a hot flash once while riding outside. I was still riding the mountain bike, with slicks, on the road when I had my last period, so I was kind of a newbie. Although the flashes continued for many years, as I said above, I really believed the outdoor activity helped them. I also lost about 10-15 lbs., which may have helped. I do remember having a couple of flashes in spin class, so I firmly believe it was being outside that helped regulate everything.