What the research actually says

Most people come to Generator to feel better: calmer, sleeping better, less wound up and less sore. The research backs a lot of that, and this page shows you where. Every study is linked, with who was in it, so you can read it yourself.

The short version

The reset: stress, sleep and a calmer mind

Here's the idea behind the Protocol, in plain words. Heat and cold are a short, controlled stress. Your body answers it, and the calm comes after. That's why people walk out feeling reset rather than wiped out, and it's what the research below keeps finding: the benefit shows up in the hours after a session, and it builds when you come back.

Cold: lower stress, the day after

A 2025 meta-analysis of randomised trials in healthy adults found stress was clearly lower 12 hours after cold-water immersion. The same review reported better sleep quality and quality of life.

Two smaller studies show what that feels like. In a brain-imaging study of 33 adults, five minutes in cold water left people feeling more alert, attentive and inspired, and less nervous, and the change showed up in how their brain networks talked to each other. In a study of 16 adults, negative mood and the stress hormone cortisol were both lower three hours after a 15-minute plunge. Both are small, with no comparison group, so read them as a picture of the effect rather than proof of it.

And one big one. In a randomised trial of about 3,000 working adults, people who finished their daily shower cold took 29% fewer sick days off work.

Heat: relaxation, recovery and sleep

Infrared heat has its own trials. In a small randomised trial of 28 mildly depressed patients, four weeks of far-infrared sauna sessions improved relaxation and physical complaints compared with no sauna. In a randomised crossover study of 16 athletes, 20 minutes of infrared sauna after training reduced soreness and improved how recovered they felt, without disturbing their recovery overnight.

The strongest heat-and-mood trial is worth knowing about too. In a double-blind trial published in JAMA Psychiatry, a single session of whole-body heating reduced depression scores compared with a sham, and the difference lasted six weeks. That was a supervised medical heating procedure for people with depression, not a sauna visit, and a follow-up trial that added heat to talk therapy didn't beat its sham. It's early science, and it's pointing in an interesting direction.

For sleep, timing matters. A meta-analysis of 17 studies found that 10 minutes in 40-42.5 C water, one to two hours before bed, helped people fall asleep faster and sleep better. That's the hot plunge, on an evening visit.

Massage: the strongest calming evidence we have

Of everything we offer, massage has the strongest research for anxiety and mood. A meta-analysis of 37 randomised studies in Psychological Bulletin found a single massage lowered anxiety, blood pressure and heart rate, and a course of massage reduced anxiety and depression by amounts comparable to psychotherapy. A later randomised trial of 47 people with generalised anxiety found six weeks of twice-weekly Swedish massage reduced anxiety more than a light-touch comparison.

Red light: sleep and skin

A 2025 review of whole-body red light studies, the kind of light our panels give off, found it may improve sleep quality, with two studies reporting better sleep, more melatonin and a lower heart rate at night. In one of them, a small study of 20 elite female basketball players, 14 nights of whole-body red light improved sleep quality and melatonin.

For skin, a controlled trial of 136 people found 30 sessions of full-body red light improved skin roughness and measured collagen density compared with no treatment.

Vibration: blood pressure and a sharper mind

A 2026 meta-analysis of 14 randomised trials found whole-body vibration training lowered resting blood pressure by about 6.6/3.0 mmHg, and by more in people whose blood pressure started higher. Another meta-analysis of 16 randomised trials found a small but real improvement in cognitive function, including executive function, the planning-and-deciding part of thinking. Those trials used programmes of regular sessions, often with simple moves like squats on the plate, so it's something you build rather than get from one stand.

Recovery: less soreness after hard work

This is the oldest and biggest body of research behind what we do.

A 2021 review of 121 randomised trials compared recovery treatments against doing nothing at all. Contrast therapy came out ahead for the soreness you feel a day or two after hard exercise, and so did cold, massage, compression, vibration and red light. A 2018 review of 99 studies found massage the most effective of the techniques it compared for soreness and fatigue, and it brought down creatine kinase, a blood marker of muscle damage.

The hot and cold rounds have their own. A meta-analysis of 18 trials found contrast therapy reduced soreness and strength loss at every check for up to four days compared with resting. For cold on its own, a 2023 meta-analysis of 20 studies found less soreness and lower perceived effort afterwards, and creatine kinase lower at 24 hours.

For compression, a 2024 meta-analysis of 17 studies found boots like ours mainly help people feel less sore after exercise. In a study of 24 Olympic-level athletes, 15 minutes in compression boots reduced muscle tenderness, and it lasted the rest of their training day.

Red light holds its own against cold. A 2022 meta-analysis of four trials (66 healthy adults after hard exercise) compared it head to head with cryotherapy, and red light came out ahead for strength recovery and for soreness, which was about a quarter lower than with cold.

Lifting to build muscle? Time the plunge

If size is the goal, wait a few hours after lifting before you plunge. In a 2019 trial, 16 men lifted three days a week for seven weeks, and half sat in 10 C water for 15 minutes after each session. Strength went up about the same in both groups, but growth in type II muscle fibres was smaller in the cold group. A 2023 paper looking at the mechanism treats that as the field's standing position. That's why we tell lifters to wait two to six hours.

The long view: a sauna habit

The famous sauna research comes from Finland, where people sauna for life. In a 2015 study that followed 2,315 middle-aged men for about 20 years, men who used a sauna four to seven times a week were less likely to die of sudden cardiac death than men who went once a week. A 2020 study followed almost 14,000 men and women for 39 years, and regular sauna bathers had a lower rate of dementia. Both studied traditional Finnish sauna rather than infrared, and both follow people over time rather than testing the sauna directly, so they show a strong association rather than proof. It's the best picture we have of what a lifelong heat habit goes with.

Who the studies studied

Most of this research studied healthy adults, and some of it studied athletes or people with a diagnosis, which we've said where it matters. None of it says anything about you if you're pregnant, managing a heart or blood-pressure condition, or being treated for something. If that's you, talk to your doctor before you plunge.

Where to go next

The Protocol is where most people start, and your first visit walks you through it. Every service has its own page: the infrared sauna, the cold plunge, the compression lounge, massage therapy, red light and vibration. Or see all seven side by side.

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Generator is a recovery studio, not a medical provider. Nothing here diagnoses or treats a condition, and it isn't a substitute for advice from your own clinician.