The days get shorter, the temperatures get colder and the training hours become scarce. The "winter blues" are in full effect.
Many athletes experience this trend each year. While there's not a conclusive cause, there are many contributing factors. These factors include reduced vitamin D production, longer hours of darkness leading to less outside exercise, and more reliance on comfort foods, which can wreak havoc on blood sugars and hormone balance.
Here's the good news: Once you identify your factors, you can also fix them.
Vitamin D affects many systems in the body. Very few foods—fish is a common example—naturally contain this vitamin, and a handful—such as dairy products—have vitamin D added. This vitamin is important for mood hormones, and we acquire it through diet and the reaction of sunlight coming into contact with our skin.
Since less ultraviolet rays are present during winter, there's a higher occurrence of vitamin D deficiency. Athletes generally need more vitamins, minerals and nutrients than others, and the combination of training and less sunlight leads to deficiency and downer moods.
Recommendations: Most adult athletes who live at latitude north of Atlanta, Georgia should consume 1000-2000 IU vitamin D per day during the fall and winter to maintain adequate blood levels. If your levels are low to start, you'll need a higher amount to help them increase. Any level below 50 ng/dL is concerning, and it should typically be higher than 70 ng/dL. If you need to raise your levels, a rule of thumb for dosage is 1000 IU per 25 pounds of body weight.
Healthy fats, especially the DHA and EPA from fish, can impact moods. To start, try eating 12 ounces of fatty fish per week (salmon, tuna, wild trout, anchovies, mussels, etc). If this is not possible, try supplementing.
Look for concentrated pills or liquids to get 1000 to 2000 mg of DHA and EPA in combination from supplements (stick to the lower end of the range if you're able to consume some fatty fish during the week). Other healthy fats—avocados, unheated olive oil, nuts and seeds, hemp, and organic coconut oil—can help as well.