Cold water swimming, all you need to know

group of five women are walking out into the sea to go sea swimming

I’ve been swimming in the sea for 4 months now and have been lucky to go when the temperature has been over 16 degrees. As the water is getting colder as we approach the Winter months, I thought I would write a post to support women as they come with us on our open water swimming journey.
Although cold water swimming seems like a crazy idea to many people, those who have experienced it feel so many great benefits from having a dip in the sea. In fact, there are many studies of open water swimmers that support the positive effects of this activity.

A review of 104 studies looked at the effects of cold-water blood circulation, the immune system, inflammation and oxidative stress. Taking a dip in water with temperatures below 20C (68F) was found to activate brown adipose tissue, a type of ‘good’ body fat which burns calories to maintain body temperature.
It also increased production of the protein adiponectin, which plays a key role in protecting against insulin resistance, diabetes and other diseases. Repeated cold-water immersions over winter significantly increased insulin sensitivity and decreased insulin concentrations. Another study suggests that shivering to become warm could also reduce the risk of type two diabetes. I’ve certainly shivered after our recent swim!
Other benefits include improving circulation as your heart works harder to pump more blood to your organs. As a result, toxins are more readily flushed out of your system, which leads to clearer skin and a healthy glow.

Cold water swimming improves your mood and reduces stress as during exercise the brain produces endorphins which help lift our mood and promote a sense of calm. Also, when you immerse yourself in cold water, you feel a stinging sensation on your skin, which your body combats by producing yet more endorphins, which produce a feeling of elation once you get out.

If you regularly exercise in open water, you will improve your sleep cycle as cold water stimulates the parasympathetic nervous system, which helps your body rest and repair itself. This promotes a feeling of relaxation and calm, which should then result in a better night’s sleep.

On regularly immersing yourself in cold water, you will experience something called cold water shock, The shock can kick-start the immune system, helping to produce more white blood cells and antioxidants, which are proven to boost your immune system and reduce various illnesses, from the common cold to heart disease.

Cold-water swimming risks
Of course, while the benefits are welcoming, it’s important to be aware of the risks of cold-water swimming, before you leap in. You will only gain the benefits of open-water swimming if you’re doing it safely, by knowing your limits and the consequences if you go too far, too quickly.

Hypothermia refers to a drop in core body temperature to below 35C (normal body temperature is between 36.5C and 37.5C), which can be serious if not spotted and treated quickly. It is a very real risk to open-water swimmers, especially in the chilliest months.
The body starts to cool from the moment exposure starts. This is generally the time when you start removing your warm, dry clothes. You then go for your swim – during which time your body continues cooling – and then on leaving the water, while you are drying off and getting dressed, your body will still be gradually cooling down.
Hypothermia refers to a drop in core body temperature to below 35C, which can be serious if not treated quickly. It takes the human body twice as long to warm back up as it does to cool down.
Working this out this means that, if it takes you roughly 7.5 minutes to get changed and into the water, you swim for 15 minutes, and then it takes you 7.5 minutes to get changed back into dry clothes again, your body will have been cooling for half an hour – not just for the 15 minutes you were swimming. It will then take your body an hour to warm back up fully once more.

Symptoms of hypothermia include:
Cold, pale skin
Blue lips
Fast breathing
Slurred speech

To treat hypothermia, it’s important to warm up, but not too quickly. Remove your wetsuit and/or swim costume, get dried and dressed quickly, and wrap up in fleece blankets. You should also have a warm drink and eat a sugary snack. We always encourage a warm flask of tea and plenty of layers and have even been known to bring a hot water bottle to put between the clothing layers near our core organs around the tummy.

Cold water shock
Cold water shock is your body’s short-term involuntary response to being immersed in cold water. It causes the blood vessels in the skin to close and your heart to begin to work harder. It also produces the ‘gasp’ response, as well as rapid breathing. Rest assured; cold water shock only last for around 90 seconds. The best way to avoid cold water shock is to take it slowly when you enter the water. Never immerse yourself by jumping in or dunking straight under the water, as I discovered last week!

You won’t get chilblains from swimming in icy temperatures – but they might appear if you warm up again too quickly. These little red bumps on your skin (which often appear on extremities such as fingers and toes after exposure to cold temperatures) are not usually serious, but they can be itchy and uncomfortable. To avoid them, make sure you don’t warm up too fast after your cold-water swim, for example by putting your hands onto a radiator. If you do develop chilblains, they are unlikely to require treatment and should disappear on their own – just try not to itch or irritate them!

Keeping yourself safe while swimming in cold water comes down to a number of factors, from knowing where to swim, to protecting yourself against the cold, to knowing when to get out!

Recommendations for cold water swimming are:
Consider wearing a wetsuit, neoprene gloves and boots and a warm hat to reduce heat loss from your heat and remain more comfortable in the water. Hands and feet always feel the cold more as they are further away from the heart.

Wetsuits not only give you additional buoyancy, meaning your body will not be working as hard to stay afloat, but they also provide warmth. When a wetsuit gets wet, it traps a layer of water between your body and the suit. As you swim, your body warms that water, providing an additional layer of insulation. Wetsuits are a preventative measure against hypothermia, but they will not make you immune to it.

Being mindful of your individual limits is one of the keys to staying safe in cold water. Never stay in longer that you are comfortable, even if a friend wants to swim for longer. The best advice I have been given is to get out while you’re still feeling great in the water. If you wait until you’re tired and shivering, you’ve left it too late.

Join us women only swimmers for a dip in the sea together every Sunday morning in Felixstowe down by the golf Road Carpark at 7am. Parking on the road is free and is free in the car park until 8am. (we may change the time to slightly later as the nights draw in – keep an eye on our weekly posts in our Facebook group here.

love Nina x


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