Cooler temperatures are here, and you know what that means: Your fitness regimen can easily be derailed.

Around this time, the least motivated among us will descend into a seemingly endless pit of carbohydrate-heavy comfort food, holiday treats and buffet-styled feasts.

Some of it may be a result of tradition and pleasant memories associated with the season – the company holiday party, grandma’s homemade dumplings or a mug of hot chocolate to go with the handful of fresh, hot cookies while watching holiday movies.

At other times, it’s just opportunity. People tend to be more generous during these months and are willing to share abundantly. So, of course, you bring home a whole pie and leftover casseroles from a potluck. You strike cooking off the to-do list and get to indulge at the same time.

Then there is biology. Mental health experts say seasonal affective disorder affects about 10 million people, with more experiencing mild forms of the condition.

They aren’t exactly clear what causes this type of depression but point to changes in a person’s biological clock, serotonin levels and melatonin levels, all which may be affected by a lack of sunlight.

In addition to feeling sad, anxious or moody, people with SAD tend to crave carbohydrates.

Meanwhile, the desire to exercise in the cooler months may be diminished due to cold, dreary weather and a false sense of security from the layers of clothing that hide what we need to improve.

My co-worker and I have braced ourselves for this time of year, as our good intentions to become more fit sometimes don’t follow through.

“You have to be more intentional about exercise during the winter months,” she said.

To start, there are some events coming up to help with that. On Dec. 5, the Ugly Christmas Sweater 5K Run is set to start and finish at the Tyler YMCA, 225 S. Vine St. For registration information, call 903-593-7327.

Lighten Up East Texas returns in January. The regional weight-loss contest is a friendly competition that helps kick off New Year’s resolutions. Follow the Fit City Tyler and Lighten Up East Texas Facebook pages for updates or on Twitter @FitCityTyler.

So how do you become more intentional in your quest to be healthy this time of year? Share your tips on Twitter by tagging @cdillard_TMT.