Once you're hooked on cold water swimming, it's hard to judge when you're not fit to swim. On top of that, comments from non-swimmers suggesting your winter swims caused the cold are just annoying. So what's truth about the cold water and the common cold?
Coughs and sneezes
Coughs and sneezes spread diseases and colds are viruses caught from humans and not from being in the cold. But old wives tales about catching a chill, or catching your death are still rife today. Why is this? Is there any truth behind the adages?
Starting with the facts, firstly colds and 'flu are caused by germs not by the cold. And secondly, cases of these infectious diseases peak when the weather's cold. The reasons why are complex, and research is conflicting. But it seems that the crux is that in colder weather, people tend to spend more time indoors together thus spreading germs more easily and immune systems are generally lower because of changes in temperature and less sunlight.
Other research suggests that viruses like rhinovirus replicated better at cooler temperatures. There are also theories that influenza thrives in cool, dry conditions, and that the dry heat of central heating lets droplets from coughs and sneezes prosper. And some researchers believe that the 'flu virus becomes tougher and easier to transmit when temperatures drop to near freezing.
Boost the immune system
Whatever the finer details about why viruses are more common in colder weather, the advice to help stop them spreading is pretty unilateral. "You can help prevent colds by washing your hands regularly," says the NHS website. It also suggests getting the 'flu jab to help protect people with lowered immune systems.
You can also boost your immune system. Eating healthily and exercising are both good immune boosters. As is cold water swimming. The theory goes that swimming in cold water is anti-inflammatory, and this reduces your body's inflammatory response to infection, improving your ability to fight off illness. In fact, many outdoor swimmers will tell you that they get fewer illnesses since starting to swim in cold water.
I'm currently suffering with my first cold in two years. Hearing my croaky voice, a couple of people have said "is that from all that cold water?" which is really irritating and very far from the truth.
Can I swim if I'm unwell?
If you do pick up a virus, can you still go swimming? The answer is simple: if you feel well enough then you can, but it's not worth pushing yourself. Some people follow the neck rule: if your illness is above your neck, then you can carry on as normal, and if it's below the neck you should stay at home.
This sounds like as much of an old wives' tale as saying you'll catch a chill if you go out in the cold! I'd say that if walking around your house and getting dressed is an effort, you should listen to your body and rest. Same goes if you have a temperature or fever, chest or ear infection or respiratory problems.
My cold is a simple rhinovirus and fairly mild - I am a bit snuffly but not ill, and I have carried on swimming through it. But, essentially, I swim outdoors three or four times a week and have done for three years, so I am about as well adapted to cold water as it's possible to be. If I were new to it, or didn't swim so frequently, I might be more cautious.
The cold - cold weather, cold water - puts an extra strain on your heart and increases your blood pressure. Your heart rate rockets when you get into cold water, so its worth considering that not only does fighting illness put a strain on your heart, but also certain drugs including some decongestants and ibuprofen can temporarily raise your blood pressure. In other words, being unwell can increase your chance of having a heart attack when you get into cold water.
Asthma is another exception. Some asthmatics find that their symptoms worsen in cold weather, If you're asthmatic, you'll probably know your triggers and cold water can be one too. Make sure you use your preventative medicine regularly and bring your reliever inhaler with you when you swim. You can keep it close by on dry land or carry it in a dry bag or tow float.
What if I have a couple of weeks off?
The good news is that a couple of weeks off cold water swimming while you recover from illness has little impact on your cold water adaptation. "Research shows that these dulled response are conserved for a period of time: if you miss a couple of weeks in cold water, you don’t start all over again," says Heather Massey in her brilliant article for the Outdoor Swimming Society. "Half of this cold water shock reduction is present 14 months following the initial batch of cold water immersions."
While you won't catch your death from regular cold water swims - far from it, you'll boost your immune system - taking yourself for an icy dip when you've barely got the energy to walk up the stairs is not a good plan. So listen to your body, rest and hydrate, and be sensible. But do correct anyone who says you're ill from all that winter swimming!