How the COLD can be good for you (yes, really!)

It may not sound as pleasant as soaking yourself in a warm bath. 

However, experts insist that taking a cold dip — even if it’s brief — will do wonders for your health.

Decades of research has linked cold exposure, whether in the form of a shower, bath or run outdoors during the depths of winter, to a myriad of benefits. 

From boosting the immune system, helping you lose weight and cutting down stress levels, MailOnline explores why embracing the cold may be the secret to better health.

Boosts immune system

Turning on the cold tap when showering, even just for 30 seconds, can bolster the immune system, experts say. 

It’s thought the shock of the cold water stimulates leukocytes — white blood cells that fight-off infections.

In fact, those who add a cold blast of water to their showers take fewer sick days, according to a 2016 study in the Netherlands.

Researchers recruited more than 3,000 participants, aged 18 to 65, who didn’t normally take cold showers. 

Those who switched to cold showers for 30, 60 or 90 seconds for three months were found to call in sick 29 per cent less than those who kept the water warm.

Aside from boosting work productivity due to taking fewer sick days, the scientists suggested that cold showers could also improve quality of life and reduce anxiety.  

Keeps you slim

Jumping into a cold shower each morning could keep you slim — but only if it leaves you shivering afterwards.

It is thought this is down to thermogenesis — the process the body uses to generate heat, which has the knock-on effect of burning calories.

One study, led by Dr Mariëtte Boon at Leiden University Medical Center in the Netherlands, found that this method was an effective way of using up energy.

The team recruited 24 adults who were monitored during a shower at 7.45am and 7.45pm.

The water temperature was lowered gradually until participants were shivering or the temperature reached 9C (48.2F). They were then exposed to this cold temperature for another 90 minutes.

Results showed that the cold temperatures led volunteers to burn more calories. There was no difference in energy burning between times of day for women. But men burned more calories during their morning shower. 

Dr Boon recommended that those looking to try cold exposure should start with cold morning showers for 20 seconds and build up to no longer than 90 seconds.

Lowers risk of depression

Despite not sounding pleasant, taking a cold shower could boost your mood.

In fact, cold exposure was found to relieve depression symptoms in a 2007 study by researchers at the Virginia Commonwealth University School of Medicine.

Cold exposure is thought activate the nervous system and increases blood flow to the brain, which triggers the release of noradrenaline.

This neurotransmitter has been shown to have a positive effect on mood.

Some studies have also found a spike in dopamine after exposure to cold water, which is known as the pleasure hormone. 

The anti-depressive effects of cold water exposure could also be, in part, caused by cold receptors in skin, notes a 2014 study on the effects of hydrotherapy.

These thermoreceptors — which detect heat and cold — send electrical impulses to the brain, which can trigger a pain-relieving effect, according to the researchers.

Separately, a medical case report suggests open water swimming could even be recommended as a treatment for depression.

Professor Michael Tipton, an expert in physiology at the University of Portsmouth, and colleagues, detailed that a 24-year-old woman had been suffering from anxiety for years and then developed depression.

After a variety of medication didn’t work, she was told to swim in cold water once a week. ‘This led to an immediate improvement in mood following each swim and a sustained and gradual reduction in symptoms of depression,’ the medics wrote.

In a follow up a year later she remained medication free.

Cuts stress

Getting cold might just be the best way to chill out and de-stress, too.

For stress levels have been shown to improve in response to cold water submersion, according to a 2004 study by researchers in Finland.

They quizzed 82 people on their mood and health in the autumn and again at the start of the year — before and after the country’s outdoor winter swimming period.

Around two-third of the group swam, while the other third acted as a control group. 

Researchers found tension levels dropped markedly among the swimmers, while their memory and mood were boosted, in comparison to those who didn’t take a dip.

The team put this down to cold water triggering the release of noradrenaline, as well as its pain-relieving and inflammation-lowering effects.

Additionally, being forced to adapt to the cold through repeated exposures to it ‘may increase the ability to withstand other kinds of stress’, they suggested. 

Improves fitness

Forcing yourself to for a jog in frosty temperatures can boost the calorie-burning powers of a workout, as well as boosting endurance.

Researchers at Aston University in Birmingham claim exercising outdoors in the winter will boost the number of calories burned, which could aid weight loss.

That’s because the body is forced to work harder to maintain its core temperature, which boosts metabolism.

Additionally, it can feel like less physical effort to exercise when it’s cold because the heart doesn’t have to work quite as hard as it would on a warm day.

In fact, researchers at St Mary’s University in London found that cold conditions bring a runner’s heart rate down by six per cent, making a run feel less physically strenuous.

It is down to this mechanism that cold weather exercise can boost endurance. 

‘In colder temperatures your heart doesn’t have to work as hard, you sweat less and expend less energy, all of which means you can exercise more efficiently,’ according to Dr Adam Tenforde, an assistant professor of sports medicine and rehabilitation at Harvard-affiliated Spaulding Rehabilitation Network.

Boosts sex life

Plunging into cold water could help to boost your libido. 

That’s because testosterone and oestrogen — the male and female sex hormones, which are intricately linked with sexual desire — rise after cold water therapy.

One paper by researchers at Northumbria University recruited 14 English Premier League academy players, who either went inside or into a -60C (-75F) cryotherapy chamber for 30 seconds after completing sprints.  

Those exposed to below freezing temperatures had elevated testosterone levels for 24 hours, results showed.

Another 2021 study by Polish researchers also found that testosterone levels increased by five per cent among men who were immersed in cold water following a sauna session.

The evidence for women’s libido is less robust. 

However, a team at the Pomeranian Medical University in Poland found that female rats that swam in cold water, rather than warm, had higher levels of oestradiol, a type of oestrogen, which could contribute to a libido boost.