Is cold water swimming healthy? Is swimming in the cold winter ocean safe or advisable? What water temperature is considered cold in cold water swimming?
Firstly, yes, swimming in the sea during winter can be healthy and safe and completely energising and revitalising. There is no doubt that cold or cool water immersion can assist with blood circulation and science says this is just the start of the benefits. Your mood will improve and your brain functions will improve as a result of more blood flowing through the head.
But, and there is a big but, you need to know some of the basics before jumping in. And you probably won’t be jumping in anyway, more like a slow walk at best.
That’s because cold water swimming done wrong can be risky and dangerous to your long term health.
Dangers of cold water swimming
- Cold water shock – When you first get in the water, you will feel the shock of the cold, especially on your head, hands and feet. The terms “Ice cream headache” and “Brainfreeze” will have new meaning for you. Your breathing will be constrained and you need to focus on your exhale to calm down. Cold water shock can lead to panic attacks requiring assistance or rescue. Enter water slowly with hands in the water. Don’t submerge your head in the cold water until you feel ready.
- Hypothermia – the big one. Hypothermia is when your body’s core temperature falls below 35C. This can lead to unconsciousness, organ damage, organ failure and cardiac arrest. You may not realise you have hypothermia or how low your temperature has fallen because your brain and body is not functioning efficiently. Never swim alone, never swim when you are shivering and never swim too long.
- Swim slow down – Cold water swimming causes your body to restrict blood flow to the arms and legs. This slows down your movements but you may not realise it. Eventually you can no longer swim properly. Don’t stay in the water if you are at all struggling or slowing down.
- After-chill – When you get out, the cold blood in your arms and legs begins to circulate again, lowering the core body temperature. You may feel colder ten minutes after your swim than during your swim. Warm tea – to warm up your core from the inside and warm clothes as soon as possible is the best solution. A steaming hot shower straight from the cold sea is less effective and not very beneficial.
How to swim in winter.
First – yes do it you will enjoy it. No one ever regretted a (safe) swim. Be prepared though if you want the benefits, not the injuries.
There is nothing enjoyable, smart, healthy or tough about swimming for long periods alone, far from shore in very cold winter water with just speedos to protect your modesty.
You can get hypothermia from swimming for long periods in relatively warm water – into the mid 20s degrees Celsius, so winter water needs to be respected.
First a wetsuit, gloves, boots, cap (or two) is the best way to protect yourself from the cold while swimming in winter. But even all this neoprene will not protect you from Hypothermia and all the associated risks after about an hour.
Second – Swim in a group, never alone, don’t stray far from shore and shorten your swim for winter.
Third: A thermos of hot tea is your best friend.
Fourth: A run along the sand before or after your swim can help keep you warmer or warm back up.
How long should I stay in the cold water?
Lifesaving Victoria say if you are in cold water for more than one hour, you almost certainly have hypothermia and are at risk of black out. Limit cold water swimming to less than one hour in winter when water temperatures are low.
If you have low body fat, you will want to be getting out of cold water after about 45 minutes, depending on the temperature.
What temperature is “Cold Water Swimming?”
Cold Water swimming is a general term but there are guidelines and health and safety regulations around cold water swimming events. Swimming Australia, FINA, triathlon organisations all have rules for cold water swimming based on health advice. All too often these rules get developed after a tragedy or many, so let’s find out more:
Cold water swimming temperatures in centigrade/Celsius:
Mid 20s degrees: warm enough for everyone
22C: Warm in Victoria, but a bit nippy for northerners from NSW and Queensland!
20C: You might like a wetsuit for long swims.
18C: Time for a wetsuit. FINA and Swimming Australia say wetsuits (not swim suits) are mandatory in OWS events under 18 degrees.
16C: FINA and Swimming Australia rules say no event can be held in water under 16 degrees.
15.5C: Swimmers who want to qualify for an English Channel attempt must swim for two hours, without wetsuit in water that is 15.5C or less.
10C: This is cold. Limit swims to well under one hour and do not attempt without a wetsuit at very least.
8C: Do not enter the water for more than a very short period of time – max 30 minutes – for the most experienced swimmers.
5C: This is called Ice swimming. Please seek medical and psychiatric advice.