As if the onslaught of holiday eating and gatherings of family and friends is not enough to slow you down in the cold dark winter nights, other conditions are at work to make you feel slower. Sure, you put on a few pounds and are struggling to find enough sunlight to avoid the cold brought on by the dark. However, hidden in the dark recesses is colder weather. As the temperature mercilessly proceeds to single digit numbers or “rider-beware” numbers which give you a negative outlook on riding, the riding then becomes more difficult.
Setting personal records on physical segments will demand more energy from you. Colder temperatures directly correlate to higher air density (DRAG). This is why riders trying to achieve goals, like the hour record, have such a difficult task of finding the right facility and time of year to make their attempt. The colder it becomes, the more watts that are required to achieve the same speed. You can use this Air Density Calculator as a tool to get an idea of how conditions can impact your riding. I know the drag coefficient does not seem to change significantly, however, the variations start to add up as the thermostat drops and if you are riding just under your FTP, the cold weather can push you right over the edge. To glean greater insight into drag, you can view our esteemed NASA web site for a mathematical break down.
In short, that early season TT may in fact be the toughest one you participate in each year. Aside from the fact that you have not raced in some time, the weather is working against you as well.