We’re now in the depths of winter’s long nights, cold days and little sunshine. The joy of Christmas is over and it can be another few months before the first buds appear. It’s no wonder that the third Monday of January is now called Blue Monday– the most depressing day of the year.

Doing anything this time of year is just that much harder than in the spring or summer. Unless you’re a lover of winter sports, being active is especially tough. For years now I’ve been getting up early in the morning to get on my bike and go swimming before the work day. This time of year, I hate it. In Vancouver the mornings are cold, wet and dark. When I get up I’m like a bear coming out of hibernation- grumpy and hungry (or at least my wife tells me).

People talk about finding motivation for being active, but when I hear the rain pelting the side of our house, my motivation is to stay warm in bed. But I know that after years of doing it, I always feel better after my exercise than before. That great feeling is like my morning coffee and it’s not just about feeling satisfied of having done it, my whole outlook seems to switch from negative to positive. Is it just in my mind though?

When we exercise our body releases hormones called endorphins. Some people refer to these as the happy hormones. Endorphins act as pain supresses and have sedative properties like morphine, but endorphins are natural. Following exercise, endorphins are released and these endorphins are believed to give us a euphoric feeling, it’s what runners term as the runner’s high, and can even be felt at low levels of activity.

The benefits of exercise appear to be even greater the worse our mood is prior to exercising. I know it’s hard to get out and exercise when in a bad mood, but I can attest to having some of my best workouts when I take out my stresses in the swimming pool or the bike, and it sure beats taking it out on your family or colleagues.

This feeling of euphoria may also last much longer than immediately after exercising. A recent survey found that exercise was followed with a greater chance of positive events and achievement throughout that day and the next. While this study was limited by self-report, other studies have found that a single bout of exercise can improve memory and cognition, and if you can think better, well then, it’s likely you’ll achieve more. So your employer should thank you for taking that mid-day walk or other activity during lunch break.

Over time, the benefits of exercise add up. When people who were not active undergo an exercise program for as little as four-weeks, there were improvements in memory, reductions in stress and anxiety. Longer-term studies have demonstrated regular exercise lowers your risk for depression, even in people doing as little as one hour per week. For those with depression, exercise is a proven therapy to reduce depressive symptoms.

While exercise appears to improve memory and cognition, it’s unclear if this translates to a lower risk for dementia. It been shown that exercise leads to an increase in BDNF (brain derived neurotrophic factor). In contrast, low levels of BDNF are associated with greater risk for Parkinson’s and Alzheimer’s diseases.

Some studies have reported no association with exercise patterns in early life and dementia with age, and studies in people with dementia have not shown improvements in cognition and symptoms with exercise. In this same study, however, there was improvement in the ability of people with dementia to perform day-to-day activities such as getting dressed and bathing, which may help to prolong independent living. Many researchers agree, though, that the current studies of exercise in dementia are of poor quality and may not be telling us the true picture since exercise improves a number of risk factors associated with dementia such as high blood pressure and diabetes.

So when you’re looking out the window into the winter’s darkness, or having trouble finishing that crossword (or blog!), think of how much better you’ll feel, and productive you’ll be after getting in some exercise. You might find yourself getting addicted to exercise, and wanting that rush of euphoria everyday.

This is Part 15 in a series of blog posts entitled Being Active While Living an Active Life.