I've run two races in cold, wet and windy weather this winter - a 10-miler in December and a 20-miler yesterday. On both occasions, whenever there was a headwind I seemed to slow down relative to the rest of the runners around me and was overtaken by several people, some of whom I caught up with again when we were no longer running against the wind. On neither occasion was the wind strong enough to make me feel as if I was in danger of being blown right off my feet.
Naively, I've assumed that since I'm 5'1" and not particularly bulky, with a reasonable power-to-weight ratio from doing other sports, the breeze should have no more impact on me than on the prop-forward types (or the lanky lassies) who are able to pelt past me on those sections, and that maybe it's psychological - I get uncomfortable so I slow down more than would be explained by the physical effects of battling the elements.
I plan to use a HRM more often in the future and that should be helpful - but I wonder if anyone knows whether physical factors such as bodyweight make a difference to our ability to maintain pace on windy days.