Like many wellness-minded millennials, I've found myself replacing pub catch-ups with weekends spent drifting between eucalyptus-filled saunas and icy plunge pools in boutique health spas. Over the past year alone, I've stood in a snow cabin in St Andrews and plunged into a crystal-clear creek in the Bavarian Alps – all in a bid to boost recovery, lower stress levels and clear my brain fog. Until recently, I never really stopped to think about whether any of it was actually good for me.
But then came the headlines questioning whether contrast therapy works in the same way for women. While the ritual is often marketed as universally beneficial, some experts believe female bodies may respond differently to repeated heat and cold exposure – particularly when hormones, nervous system regulation and recovery are brought into the equation. Part of the issue lies in the research itself, with women accounting for just 12–18% of participants in thermoregulation studies over the past decade.
Even Gwyneth Paltrow recently admitted she now cold plunges more 'sparingly' than her husband, explaining on a podcast that women may benefit from shorter sessions, warmer temperatures and gentler protocols overall. I'll admit, my own experience has only ever been positive – I feel clearer-headed and more energised afterwards. But after speaking to neuroscientists and longevity doctors, I'm starting to wonder if contrast therapy really needs to be quite so extreme.
© Getty ImagesWhat actually happens to your body during contrast therapy?
"Contrast therapy works by deliberately exposing the body to short, controlled doses of thermal stress," explains Dr. Mohammed Enayat, longevity physician and founder of HUM2N Longevity Clinic. "Heat causes vasodilation, where blood vessels widen and circulation increases, while cold exposure causes vasoconstriction, where blood vessels narrow and stress hormones such as noradrenaline rise."
Alternating between the two essentially creates a form of "vascular training", repeatedly challenging the cardiovascular and nervous systems to adapt.
This stress response is often referred to as hormesis, or what wellness circles like to call 'good stress'. "The stress has to be controlled, recoverable and appropriate for the individual," says Dr. Enayat. "Heat may activate heat-shock proteins and support cellular resilience, while cold exposure can increase alertness, perceived energy and short-term stress tolerance."
In simpler terms, that post-plunge rush many devotees rave about is partly down to a flood of adrenaline, endorphins and feel-good neurotransmitters triggered by the sudden shock of cold water.
For neuroscientist and Arc Community co-founder Alanna Kit, one of the biggest misconceptions is that more extreme temperatures automatically lead to better results. "The stimulus needs to be uncomfortable but sustainable," she explains. "Everything about contrast therapy is an invitation rather than a fixed prescription." Essentially, consistency matters far more than treating every session like an endurance challenge.
Do women respond differently to cold plunges and saunas?
"The majority of foundational studies on cold exposure and sauna have used male participants, which means we're extrapolating a great deal when advising women," explains Kit.
That gap is important because, physiologically, women can respond quite differently to cold exposure. Women typically have a higher percentage of subcutaneous fat and a lower muscle-to-mass ratio, meaning we often cool more slowly but retain cold for longer afterwards. "Women also often report a stronger initial emotional response to cold," Kit adds, noting that this is more likely linked to differences in stress response than tolerance itself.
Hormones play an important role, too. Kit explains that women's thermoregulatory responses can shift throughout the menstrual cycle, with oestrogen influencing everything from vasodilation to sweating thresholds.
"The same sauna session can feel markedly different at different points in the month," she says. During the luteal phase, when progesterone rises and oestrogen drops, she often advises women to either avoid cold plunging altogether or opt for a warmer temperature instead, as pain sensitivity and stress responses may be heightened during this time. "For this phase, I recommend focusing more on the heat for vasodilation and muscle relaxation."
She's keen to stress, though, that contrast therapy is far from one-size-fits-all. "Some people find the cold instantly clarifying, almost euphoric, while others experience an initial panic response before gradually settling into calm through breathing exercises." Factors such as sleep quality, stress levels, hormonal shifts and previous burnout can all shape how someone responds to heat and cold exposure on any given day. "The tool doesn't change, but how you meet it does," says Kit. "We're working with different edges and capacities here."
What's the best way to do contrast therapy?
Start gently
"The goal is not to prove toughness," says Dr Enayat. "The best protocol is the one you can recover from." For beginners, he typically recommends starting conservatively with 10 to 15 minutes of heat exposure followed by 30 to 90 seconds of cold, repeated two or three times.
More experienced users may build up to longer sessions, but both experts agree that more extreme temperatures don’t automatically lead to better results. In fact, one 2024 study on women found sauna sessions at 80°C improved mood and reduced tension, while more excessive heat exposure (120°C) was linked to dizziness, nausea and heat stress symptoms.
Consider the time of day
According to Kit, cold exposure tends to work best earlier in the day, when the body naturally experiences a rise in cortisol. "Cold naturally triggers a cortisol and norepinephrine spike," she explains.
"They sharpen focus, drive motivation and align with your body's natural circadian rhythm at wake."
In the evening, however, the logic flips. Kit says ending on heat instead of cold may be more supportive for relaxation and sleep, as sauna bathing helps promote parasympathetic activity and mirrors the body's natural pre-sleep cooling process.
Don't underestimate your breath
"When you enter cold water, the body's first reflex is the cold shock response – a sharp gasp, elevated heart rate and flood of adrenaline," explains Kit.
Slow, controlled breathing helps interrupt that stress response and signals to the nervous system that the body is safe, making the experience feel significantly more manageable. Kit also recommends allowing the body to warm naturally for a few minutes after cold exposure rather than rushing straight back into the sauna. "Think of it as letting the cold do its full work before you introduce the next signal to the mind and body," she says.
Who should avoid contrast therapy?
"Cold exposure causes a sharp sympathetic response," explains Dr. Enayat. "Heart rate, blood pressure and breathing can all change very quickly."
For healthy individuals, that stress response may be adaptive, but for others, it can place unnecessary strain on the body. "People with cardiovascular disease, uncontrolled high blood pressure, arrhythmias, severe Raynaud's, poorly controlled asthma or a history of fainting episodes should approach contrast therapy cautiously and speak to a medical professional first."
Dr. Enayat also advises against cold plunging during acute illness, fever or periods of significant exhaustion. "If someone is already severely stressed, underslept, overtrained or struggling with burnout symptoms, adding more stress is not always the answer," he says.
© Julien L. BalmerThere are also certain situations where timing matters. Dr. Enayat generally advises avoiding cold plunges immediately after heavy strength training if muscle growth is the goal, as emerging research suggests cold water immersion may blunt some of the inflammatory signalling needed for muscle adaptation.
For women in particular, Kit recommends paying attention to energy levels, stress and different phases of the menstrual cycle rather than forcing yourself through an intense protocol. "The best approach is the one that leaves you feeling regulated, not depleted," she says.
