Exercising in winter can help your immune system ward off cold and flu viruses
It's dark when you get home from work and an early morning start requires your phone light to find clothes.
You need warm socks just to potter around the house and it's getting harder to maintain the exercise regime you committed to in summer.
If motivation to keep exercising has started to elude you, it might help to know that letting your exercise slip can potentially have impacts on your immunity.
In other words, if you skip your regular workout in the colder months, you could be facing an increased risk of the common cold or other infections — alongside the usual drawbacks of inactivity (lower mood, high blood pressure, weight gain… the list goes on).
Here's what you need to know about the links between exercise and immunity, including exactly how much exercise you need to do for your immune function to reap the benefits.
How exercise impacts immunity
"Exercise is really well associated with how well our immune function works, in lots of different ways," says Kate Edwards, a senior lecturer in exercise and sport sciences at the Faculty of Health Sciences at the University of Sydney.
Regular physical activity is also associated with fewer cases of flu, pneumonia and even decreased mortality, studies have shown.
Wondering how that works?
When you do moderate-to-vigorous exercise such as brisk walking, cycling or swimming, there are several positive, temporary changes in your immune system, including enhanced movement of important immunity-related cells throughout the body.
When repeated on a regular basis this exercise offers health benefits, including fewer illnesses and less systemic inflammation in the long term.
What's more, exercise helps maintain a healthy weight, which along with other factors like healthy food intake and regular sleep, is one of the pillars of healthy immunity, says Yasmine Probst, senior lecturer in nutrition at the University of Wollongong.
"When you have increased body weight, your body has higher levels of inflammation and that inflammation can be related to how your immune system works," Dr Probst says.
Doing something is better than nothing
If it's too nippy outside to face the idea of your regular jog, don't despair. You can keep your immune system strong using alternative (winter-friendly) forms of exercise.
"You can do [a lot] at home," says Dr Edwards. "Regimens that just use your body weight … there's lots of circuit-type exercises — do 30 seconds exercise, have a minutes rest — online."
A quick internet search will give you lots of examples of workouts you can do at home and without equipment.
It might be a good time to try indoor activities such as climbing, squash, soccer, basketball, badminton, volleyball, aqua aerobics, Pilates or yoga. Or there's always the gym.
Your immune system will benefit from mixing up your routine, says Dr Edwards.
"My basic rule is that all exercise is good and we should do a mix of exercise for a range of different reasons, and that holds true for your immune system as well," she says.
How much is enough?
Your immunity will gain the most benefits if you're hitting the national exercise guidelines, which suggest accumulating 150 to 300 minutes of "moderate intensity" physical activity, or 75 to 150 minutes of "vigorous intensity" physical activity, each week (or an equivalent combination of both).
But if that's just not going to happen for you this winter, don't despair.
People who exercise only moderately — "maybe three times a week" — still demonstrate improvements in their immune system, says Dr Edwards.
"If you can go for a walk twice at the weekend and maybe once during the week, that's still good," she says.
Not being as young and spritely as you once were isn't an excuse to let that fitness routine lapse in winter, sadly. In fact, quite the opposite.
"Your immune system changes as you age, so the younger you are, the stronger your immune system basically," says Dr Edwards. "The effects of exercise tend to get more important as we get older."
Keep in mind that the national exercise guidelines outlined above apply up to age 64. (From age 65, try to accumulate at least 30 minutes of moderate intensity physical activity on most, preferably all, days, the guidelines suggest.)
Just don't overdo exercise when sick
There are a couple of situations where your immunity can be harmed, not helped, by exercise in winter.
Exercising particularly hard or for an extended period might suppress your immunity for a short window afterwards, leaving you more likely to catch a cold or other bug.
Studies have found the odds of becoming sick increase two- to six-fold after extreme exercise events.
And if you're coming down with the cold or the flu, it's sometimes — but not always — unwise to push on with your usual fitness routine.
You can use what athletes call the "neck check" to work out whether it's safe to exercise, according to David Pyne, a sports scientist and researcher with the Research Institute for Sport and Exercise at the University of Canberra.
If your symptoms are from the neck up and not too severe, moderate exercise generally won't hurt you and might even be beneficial, Dr Pyne says. But if your symptoms are more troublesome and they're mostly below the neck, exercise is not recommended.
But for those of us unburdened by a nasty chest cold — it's time to layer up, bite the proverbial bullet and get sweating.
Your immune system will thank you.
Article from ABC Life