IDAHO FALLS, Idaho -

Every year about this time, many of us start to feel it: that groggy feeling doctors call seasonal affective disorder, or SAD.

SAD hits millions of Americans with bummed-out winter feelings. Doctors attribute it to how little light we get during these dark winter months. From there, it can be a vicious cycle, but there is hope.

“When it's dark already by 5 o'clock, it seems like you never get that vitamin D and sun,” said Andrew Daugerty, who is taking his seasonal affective disorder medication. “I think it's just years of repetition.”

It's not a prescription, but 30-minute workouts Daugherty said are the ticket to make up for the gloom of winter.

“When you have light reduction, your body naturally doesn't produce some of the feel-good hormones,” he said.

At Eastern Idaho Regional Medical Center, exercise physiologist Eric Jackson said seasonal affective disorder hits about 20 percent of Americans each year. Dark skies mean less of the hormone seratonine, a mood regulator.

The common symptoms are low energy, feeling a little more depressed. A mopey attitude sometimes means even less motivation to go to the gym, but Jackson said it's the perfect cure.

“You exercise, your body produces a hormone called endorphine, and that is one that will also improve your mood overall,” said Jackson.

The biggest hurdle is that first workout.

“If a body stays at rest, you always want to stay at rest,” he said. But once you start, “If you stay in motion, I feel it does help out considerably.”

So what about fighting light reduction?

Our overnight producer uses a special light in the newsroom that he calls it his “happy” light. They are sold at many big box retailers and online. They emit light with vitamin D to help offset some of the gloom.

In addition, Jackson said taking a walk after a meal, even if it's dark out, can be a perfect first step to overcoming seasonal affective disorder. Other ways to combat SAD include a diet free of processed food, eating “clean” foods like fruits and vegetables.