Contrast therapy is a sauna and an ice bath, one after the other. The usual pattern is 15 to 30 minutes of heat, then 1 to 5 minutes of cold, repeated 1 to 3 times. Finish on cold if you want to feel sharp. Finish on heat if you want to wind down.
Here’s the honest bit up front. The evidence for contrast therapy is real but thinner than the marketing, and most of it comes from hot and cold water, not a sauna and a plunge. Below: what the research backs, which order to go in, a beginner and an experienced routine, timing around training, and safety.
What contrast therapy is and why people do it
The idea is simple: swap between heat and cold in one session. In a gym that’s a sauna and a cold tub, also called sauna and cold plunge or hot and cold plunge.
Heat opens your blood vessels and lifts your heart rate. Cold clamps them down and makes you gasp. People do it for less soreness, for the wide-awake feeling afterwards, and because it feels great. The first two are worth checking.
What the evidence actually supports
Less soreness after training
The best data on contrast comes from studies that swap hot and cold water, not sauna and plunge. The biggest review of hot-and-cold water recovery found it does ease muscle soreness over the next few days compared with just resting. It also found no clear edge over cold water alone. So the cold is doing the measurable work, and the heat makes it more pleasant.
Cold on its own holds up well. A University of South Australia review found cold water helped muscle power bounce back and cut soreness within 24 hours, most clearly after endurance or high-intensity work. Think runs and conditioning classes, not heavy lifting.
Heat after training
Heat after training has a decent case too. In one small study of competitive runners, 3 weeks of a 30-minute sauna straight after training pushed run time to exhaustion up by 32%. It was a handful of runners, so call that promising rather than proven.
Cold and sauna together: the winter swimmers
The closest anyone has come to studying sauna and ice bath as a habit is Danish research on winter swimmers: men who mixed cold dips with sauna a few times a week produced more heat in the cold than people who didn’t. It was men only, and long-time swimmers at that. We unpack the limits of that study, and the “11 minutes a week” figure that came out of it, in our guide to ice bath benefits.
What the evidence doesn’t show yet
Almost all the contrast research is water to water: hot bath, cold bath. Very few trials have tested a sauna then a plunge, which is what most of us actually do, and dry heat at 55 to 65 degrees is a different load from a warm bath.
Nothing shows contrast beats cold alone for soreness, or that the combination burns fat or extends life. The immune and resilience effects that have been measured come from the cold itself, not from alternating. It’s a sensible habit that feels good, with a thin evidence base.
Sauna and ice bath: which order?
No study settles this, so what follows is coaching practice. The state you finish in is the state you walk out with.
Sauna first, cold to finish: daytime and before training
Heat loosens you up. Finishing on cold leaves you sharp. In one small study, people felt more alert and less stressed after a short cold dip. Want to walk out ready for the day or a training session? Sauna then ice bath.
Cold first, heat to finish: evenings
Flip it at night. Get the hard part done in the cold, then let the sauna warm you through. Leave at least an hour to cool down before you sleep.
A beginner routine and an experienced routine
Both routines use our set-up at 5EW: a FAR infrared sauna at 55 to 65 degrees and a cold tub at 6 degrees. Colder water always means less time.
| Beginner | Experienced | |
|---|---|---|
| Rounds | 1 | 2 to 3 |
| Heat per round | 15 to 20 minutes | 10 to 15 minutes |
| Cold per round | 1 to 2 minutes | 3 to 5 minutes |
| Finish on | Cold by day, heat at night | Cold by day, heat at night |
| Sessions a week | 1 to 2 | 2 to 4 |
At 5EW a session is one round: a 30-minute sauna booking, then 3 to 5 minutes in the cold tub. For most people that’s plenty.
New to cold? Expect the gasp and fast breathing the first few times. Get out when your breath won’t slow down, not when the timer says. More experienced? Add a round before you add minutes. Past 5 minutes at 6 degrees there’s no evidence you get anything extra.
Timing contrast therapy around training
Don’t ice bath straight after lifting if you want muscle
This is the catch most sauna and cold plunge routines skip. Cold water straight after a strength session appears to blunt muscle growth: in a University of Queensland trial, 12 weeks of cold water after every lifting session meant less muscle and less strength than an active cool-down. It doesn’t wipe out your gains, but it costs you some.
Our rule: if you lift to build muscle, put several hours between your last set and the cold tub. Lift in the morning, contrast in the evening. Or keep contrast for rest days.
Fine after conditioning, and heat is fine any time
Cold after a hard run or conditioning class is where the recovery data is strongest, so sauna then ice bath the same afternoon is a good fit.
The lifting concern is about the cold, not the heat. If you’ve lifted and want the recovery zone the same day, take the sauna and save the cold for later.
Safety
Two things matter: cold shock and the swing in blood pressure.
Cold shock is the gasp and the spike in heart rate and blood pressure in the first few minutes. It’s the main danger of cold water, and the risk is highest for people with heart conditions. Enter slowly, breathe out long, never get in alone, and don’t hyperventilate first.
Sauna is gentler, but not nothing. It pushes your heart rate and blood flow up about as much as a moderate workout. So stand up slowly afterwards and pause on the edge of the tub before you lower in.
Drink 250 to 500 ml of water before the sauna and rehydrate after. No alcohol with sauna, ever. Heart condition, uncontrolled blood pressure, Raynaud’s, recent surgery or pregnant? Check with your GP first. And get out if you feel dizzy, sick or your heart is racing.
How often?
Aim for 2 to 4 sessions a week. Daily contrast is unlikely to harm a healthy adult, but there’s no evidence it adds anything, and it makes it harder to keep the cold away from your lifting.
How we do it at 5EW
The recovery zone at 79 Queens Parade has a FAR infrared sauna and a cold tub, each in its own private room. The infrared sauna is bookable in 30-minute sessions and runs at 55 to 65 degrees. The cold tub sits at 6 degrees. You don’t need to be a member to book either.
Our protocol: hydrate before the sauna, sit or lie back for the session, rinse, then lower into the cold tub to shoulder depth and slow your breathing. Three to 5 minutes is plenty, or 1 to 2 minutes if you’re new to cold. Then let your body rewarm on its own for a few minutes before any hot shower, and rehydrate.
Want the detail on each half? Read our guides to infrared sauna benefits, ice bath benefits and how long to stay in a sauna.
Frequently asked questions
Sauna or ice bath first?
No study settles it, so let the end state decide. Sauna first and cold to finish leaves you alert, which suits mornings and pre-training. Cold first and sauna to finish helps you wind down, which suits evenings. Either way, keep the cold short and get in slowly.
How long should you wait between sauna and ice bath?
Nobody’s tested the gap, so there’s no proven number. A quick rinse and the walk between rooms is enough, about 1 to 2 minutes. Stand up slowly after the sauna, because your blood pressure drops when you rise from heat, and pause on the edge of the tub before you lower in.
Can you do contrast therapy every day?
Most healthy adults could, but there’s no evidence daily contrast beats 2 to 4 sessions a week. The Danish winter swimmers were only in the cold a few times a week. Daily cold also makes it harder to keep the ice bath away from your lifting, which matters if muscle is your goal.
Does contrast therapy help with weight loss?
Not really. Cold does lift your metabolic rate while you’re in the water, and the winter swimmers had more active brown fat, but the extra energy burned is small and no trial has shown fat loss from sauna and ice bath. Training and food do the fat loss.
Is contrast therapy safe with high blood pressure?
Check with your GP first. Heat drops your blood pressure, cold spikes it, and swinging between the two is a big change in a short time. If your pressure is well controlled and your doctor is happy, start with sauna only, then add very short cold exposures. If it’s uncontrolled, skip the cold.
Keen to try sauna and ice bath in private rooms? You can book a session at 5EW whether or not you’re a member. Start with one round, keep the cold short, and build from there.
Written by the coaching team at 5th Element Wellness in Fitzroy North. Meet the coaches.
