Going between heat and cold (contrast therapy, if you want the gym name for it) is the whole point of most Irish outdoor saunas. The heat makes the cold bearable, and the cold makes the heat feel extraordinary. Here's how to do it without overdoing it.
A simple routine
- Heat: 10 to 15 minutes in the sauna, or until you're properly warm and ready to leave.
- Cold: 30 seconds to 2 minutes in a cold plunge or the sea. Breathe out slowly as you go in.
- Rest: 5 to 10 minutes outside, wrapped up, letting your body settle.
- Repeat for 2 to 4 rounds.
That's it. You don't need longer in the cold to get more out of it, and staying in until you're shaking is a sign you've gone too far, not that it's working.
The first 60 seconds of cold
The gasp when you hit cold water is involuntary. It's called cold shock, and it's strongest in the first minute. Get in slowly, keep your head out, and focus on long breaths out. If you're plunging in the sea rather than a tub, stay where you can stand.
Ice bath or sea?
A purpose-built plunge tub is usually 3 to 10°C and you control exactly how long you're in. The Irish sea runs roughly 8 to 10°C in late winter and 15 to 17°C at the end of summer, and comes with waves, tides and currents. Both work. The sea needs more respect.
How to finish
There's no single right answer. Finishing on cold leaves most people feeling sharp and awake; finishing with a last short round of heat is gentler and warmer for the drive home. In winter, get dressed and warm quickly either way, because your core temperature can keep dropping for a while after you get out of cold water.
Who should be careful
Both heat and cold put load on the heart and blood pressure. If you have a heart condition, high or low blood pressure, are pregnant, or take medication that affects any of those, talk to your GP before trying it. And never combine either with alcohol.