If you're not a regular cold water surfer, you'd agree there is usually nothing pleasant about the first few seconds.
You have pulled on your wetsuit, walked across the sand, and reached the shoreline. The first wave runs over your feet, and your body reacts before your mind has had time to negotiate.
Your breathing changes, your heart beats faster, and, for a moment, walking into the ocean can feel like a bad decision.
"What am I doing here? My hands, my feet, and my forehead are freezing," one might say to themselves.
A few minutes later, the experience can be completely different. You are paddling, catching waves, and paying attention to the ocean's rhythm.
The cold is still there, but it no longer feels like the main event.
Congrats - the change is (partly) physiological.
Cold water produces an immediate stress response, while repeated exposure can help the body become better adapted to the stimulus.
Exercise, concentration, and the anticipation of catching waves then add another layer to the experience.
So, could the unpleasant part of surfing in cold water help explain why many people feel so good afterward?
Because you remember you did, right? The science does not provide a simple answer, but it offers some clues.
Here's what's really interesting about this cold water paradox. And it involves a concept you probably haven't heard of yet.
We hadn't, too, until penning this story for you.
Your body reacts before you do
Let's dissect the cold water experience.
The first thing we need to know is that water removes heat from the body much faster than air. Probably nothing new here for you, dear reader, correct?
When the skin suddenly meets cold water, blood vessels near the surface constrict, heart rate and blood pressure can rise, and breathing can become rapid and difficult to control.
It's a mechanism known as the cold shock response.
It is particularly important in water below about 59 °F (15 °C) and can cause an involuntary gasp followed by rapid breathing. Unexpected immersion can therefore be dangerous, even for experienced swimmers.
A surfer wearing a neoprene wetsuit and deliberately entering familiar conditions is in a different situation from someone falling unexpectedly into cold water.
Nevertheless, the underlying physiological response still occurs.
Research has found increases in heart rate, blood pressure, breathing, and metabolism during cold exposure, together with increased release of catecholamines such as adrenaline and noradrenaline.
With repeated exposure, some of these reactions become less pronounced.
That process is known as cold habituation. And this is where it gets really curious.
A 2024 study (Barwood et al., 2024) found that repeated cold water immersion reduced several components of the cold shock response, including heart rate and breathing responses.
Measurable habituation could occur after roughly four immersions, although the studies varied considerably.
There is even some research involving surfers.
A small 1978 study (Rochelle & Horvath, 1978) found that surfers immersed in 66 °F (19 °C) water maintained warmer toes than non-surfers and showed a later and less intense shivering response.
Their heart rate also rose initially before falling towards resting levels.
The study is old and small, so it cannot explain how every surfer adapts to cold water. It does, however, provide an early example of the kind of adaptation that scientists have observed.
The cold may be a hormetic stress
Now, this is where hormesis enters the story. Hormesis describes a situation in which a small or moderate stressor produces an adaptive response.
Exercise is a familiar example: physical activity places stress on the body, followed by recovery and adaptation.
Cold exposure can produce a similar pattern.
The body detects a thermal challenge, activates its stress response, and attempts to protect its core temperature. With repeated exposure, some of those responses can become more efficient.
For a surfer, the cold is also combined with exercise.
Paddling produces heat, while balance, wave selection, and positioning require constant attention.
That makes a winter surf very different from sitting motionless in an ice bath or cold water shower. The thermal stress is constantly changing as the surfer paddles, waits, catches waves, and moves through the water.
Caution, though. Hormesis should not be interpreted as "more stress is better."
Cold exposure becomes dangerous when the body's ability to maintain temperature and physical performance is overwhelmed, and you eventually enter a stage of hypothermia.
Why do you feel so awake?
Many surfers know the sensation, especially in winter. You leave home early for a dawn patrol, still half asleep, and enter cold water.
A few minutes later, you are wide awake.
Cold exposure stimulates the sympathetic nervous system and increases the release of catecholamines, which are involved in the body's stress response and can increase alertness.
There is also evidence that some psychological effects of cold exposure can appear after the exposure rather than immediately.
In a 2023 study (Reed et al., 2023), 16 healthy adults spent 15 minutes in 50 °F (10 °C) water.
Positive affect did not increase immediately afterward, but negative affect was lower three hours later, while cortisol was also lower.
The study was small and does not prove that cold water improves mood in everyone.
Then, a 2025 systematic review (Cain et al., 2025) of 11 studies involving 3,177 participants found that cold water immersion was associated with lower stress 12 hours after exposure.
It did not find a significant overall improvement in mood, although some studies reported improvements in sleep and quality of life.
The researchers stressed that the evidence remains limited by differences between studies and relatively small samples.
So the familiar post-surf feeling does not need a dramatic explanation.
The body has responded to cold, the nervous system has become highly activated, and the surfer has then spent time exercising and concentrating on the ocean.
The experience has changed.
Cold water is not simply an anti-inflammatory
Cold water is often described as a natural anti-inflammatory treatment. But the reality is more complex.
Cooling tissue can reduce blood flow and alter metabolic activity, and cold water immersion has been studied as a recovery method after strenuous exercise.
A meta-analysis of 52 randomized controlled studies (Batista et al., 2023) found reductions in muscle soreness and improvements in perceived recovery after some forms of high-intensity exercise.
But cold exposure does not simply switch inflammation off.
Another 2025 thorough review found that inflammatory markers actually increased immediately and one hour after cold water immersion in the studies it examined.
Some other effects, including changes in stress, appeared later.
So, inflammation isn't necessarily harmful. It is part of the body's normal response to stress and tissue repair. All good.
Framing it within surfing, it's accurate to describe cold water as a physiological stressor that can produce adaptation rather than as a natural anti-inflammatory drug.
Surfing adds something a cold plunge cannot
Here's a subtle difference we need to address.
A cold plunge gives the body cold water; surfing adds movement, concentration, anticipation, and reward.
Research on surfing has found associations with positive psychological outcomes, although the evidence does not establish that surfing is superior to other forms of exercise.
A 2025 study (González-Devesa et al., 2025) involving military personnel found generally beneficial effects on anxiety, depression, and positive affect, while also noting important limitations in the available studies.
Surf has become a form of therapy prescribed by doctors. Yes, you've read it well.
Also, research on outdoor swimming ("It's in the water," 2025) provides another useful comparison.
In a 2025 qualitative study of ten regular outdoor swimmers, participants described exercise, contact with nature, emotional regulation, and cold exposure as important parts of their experience.
These were reported experiences, not proof of medical effects.
Surfing adds the constant demand to read the ocean and respond to the incoming waves a surfer is given or blessed with.
What we've got here actually has a curious sequence.
The cold initially demands a strong physiological response, exercise generates heat, concentration takes over, and the human graced with surfing skill gradually stops thinking about the temperature and starts thinking about the next wave.
Surfers are a different breed.
Words by Luís MP | Founder of SurferToday.com
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