Joined: Nov 2008
Posts: 457
Likes: 1
From: Los Angeles
Bikes: Trek 7.3fx, Peugeot PX-10, Fuji Roubaix Pro ('04), Cannondale R600, Triumph Roadsters, Raleigh 20, Univega Nuovo Sport, Schwinn Sierra, Bianchi Osprey, Peugeot NS-22, Batavus Champion, Haro Pulse.
You will have to exert yourself more strenuously in cold weather to achieve a given level of performance than would at a more comfortable temperature. Correct breathing can also be more uncomfortable, which might lead you to breathe less efficiently and get hypoxic--making you dizzy. Maybe you just need to back off a little and let yourself adjust to the seasonal conditions?