Sleeping or eating a little more than usual? Feeling melancholy for no apparent reason? Craving carbohydrates and suffering from couch potatoism? While these are common and somewhat normal reactions to the change of seasons, the short days and long nights of fall can actually trigger a condition known as seasonal affect disorder, or S.A.D.—a cyclical condition associated with symptoms of depression, lethargy, and fatigue.

The signs and symptoms of S.A.D. usually come and go at the same time each year, usually appearing in late fall or early winter and then going away during the warmer, sunnier days of spring and summer.

So what causes S.A.D.? Well, the exact cause is unclear. However, this condition has been linked to a biochemical imbalance in the brain triggered by shorter daylight hours and lack of sunlight during the winter. As seasons change, people experience a shift in their biological clocks. This can throw them off their daily routines, and this disruption may then trigger depression. Some researchers believe the disorder may be linked to increased production of melatonin, a sleep-inducing hormone. Others believe that lack of sunlight causes a drop in brain serotonin levels, a natural brain chemical that affects mood.

For the person trying to manage his or her weight, behavior changes associated with S.A.D. may pose a big challenge. Many people with S.A.D. find themselves craving high-carbohydrate foods, withdrawing from family and friends who've been providing social support, and lacking the drive and motivation to participate in normal activities— such as getting physical activity on a regular basis. All of these changes in behavior can certainly provide a seasonal roadblock to the best of your weight-control efforts.

What can you do to prevent or manage the signs and symptoms of S.A.D.? Well, first and foremost, if your symptoms are significant enough that they are impairing your life (e.g. you are experiencing problems at work or school, abusing substances such as alcohol, or are completely withdrawing from family and friends), seek medical advice. An experienced health care professional can help diagnose the situation and come up with the best treatment approach. However, if you are like many people and experience seasonal mood changes that are mild in nature, there are plenty of steps you can take to lift your spirits. To keep you feeling emotionally strong and on track with your weight-management goals, try these five mood-lifting strategies:

• Make healthy carbohydrate food choices. What you eat can affect your mood and energy levels. Choose complex carbohydrates (whole grain bread and cereals and fresh fruits and vegetables) and avoid the refined carbohydrates (white bread, white rice, and sugar-laden snack foods). Complex carbohydrates are digested more slowly and help stabilize blood sugar, which in turn can help sustain your energy.
• Exercise. Although the cold weather makes you feel like hibernating rather than hiking, resist the urge to rest and "just do it." Regular exercise (indoors at the mall, at the gym, or a good workout raking the leaves in the yard) improves mood, increases your energy, and helps you sleep better.
• Get enough vitamin D. Most people know that a little sun exposure to our skin helps the body produce vitamin D, a nutrient with hormone-like activity in the body that not only helps keep your bones strong, but helps keep your spirits high. With colder weather, many people choose to spend less time outdoors. This lack of natural sunlight can lead to depressed production of brain chemicals that positively affect mood. So if you can, try to spend 10–15 minutes outdoors every day to boost your mood. To make sure you are getting enough vitamin D, take a multivitamin with plenty of vitamin D on a daily basis.
• Take a little "me time." The coming of winter also means the coming of the holiday season, and for some, this time of year can be especially stressful. The demands of familial obligations can take their toll, leaving you with the doldrums. So remember to take a little "me time." Make plans to pamper yourself with something you enjoy—a massage, a weekend getaway, or a girls' or guys' night out.
• Reach out and touch someone. The power of friends and family should never be underestimated. If and when you're feeling a little low, don't be afraid to reach out to the people in your life whom you care most about and who care most about you. Ask for help when you need it. A simple phone call from your sister, an e-mail from your best friend, or lunch with a co-worker can brighten your day and your outlook on life.

The air is cool and crisp. The leaves are turning incredible colors, like burnt orange, bright red and golden yellow. Autumn is almost here and you can feel the seasonal change approaching. But before you feel like you want to hibernate for the winter, take advantage of this wonderful time of year to renew your exercise goals, establish a new routine and start creating good habits for the upcoming winter.

With shorter amounts of daylight and cooler temperatures, finding new ways to stay fit might be in order. Here are 12 great Fall fitness ideas for you and your family:

1. Fall is a great time for a walk in the woods. Gather leaves of all shapes and sizes and when you're done making a collage, frame it, and display it on your mantel.
   
   
2. Venture out for a walk to the city park.
   
   
3. If it's too chilly, rainy, or too dark, walk in your local mall.
   
   
4. Go for a hike together as a family.
   
   
5. Bundle up and visit your local beach and go for a walk. Collect shells, play frisbee.
   
   
6. Football season is here so gather up some family and friends for a game of catch or touch football.
   
   
7. Buy a new exercise video or dvd. Use it as a backup when it's too cold to exercise outdoors.
   
   
8. Join the YMCA or a local gym. Take advantage of indoor exercise equipment, group exercise classes. Try something new like pilates or yoga.
   
   
9. Rake leaves. Raking leaves for 30 minutes burns about 100 calories. Make a big pile and let your kids jump in them. Better yet, you jump in them. Then you'll have to re-rake them up, and will burn a few more calories!
   
   
10. Plant fall bulbs in your flower garden.
    
    
11. Visit your local pumpkin patch and walk the entire patch looking for the best pumpkin.
    
    
12. Visit a local corn maze and find your way from the entrance to the exit (tip: getting lost burns more calories and leads to more fun!).