Originally Posted by
Redbullet
Lower or higher gusts are always present. When come from the front, they produce short, intermittent surges of power that muscles don't like at all (tail wind generates the opposite, which is perceived as refreshing for muscles). Breathing is always a little more difficult with front wind (I never could explain this).
Then: speed is lower, wind noise is higher - these contribute to overall decrease in comfort, which psychologically is perceived as making a bigger effort.
Yes, there is a big perceived difference between a steady headwind and a very gusty headwind. When you're working against, say, a steady 12 MPH headwind, it slows you down but you put down whatever power you desire and accept the speed results you get. But a 12 MPH wind with sudden 30 MPH gusts is something else again.