Cryotherapy vs. Cold Plunge:
Two Ways to Use Cold as Medicine.

Cold has been used for recovery for as long as athletes have had ice. What has changed is the precision. We can now measure what a cold exposure does to hormones, metabolism and recovery markers, and we can deliver it in two very different ways: ultra-cold air in a cryotherapy chamber, or cold water in a plunge. They are not the same tool. Used correctly, each one does something the other cannot.

What Cold Does to the Body

Sudden cold on the skin is read by the nervous system as a threat, and the response is immediate sympathetic activation.

• Norepinephrine and dopamine. In a controlled study, one hour of head-out immersion at 14°C (57°F) raised plasma norepinephrine by about 530 percent and dopamine by about 250 percent, while cortisol did not rise. Over 12 weeks of regular exposure, both whole-body cryotherapy at -110°C for two minutes and 20-second ice-water dips produced two- to threefold norepinephrine increases every session, with no habituation of that response.
• Vasoconstriction and inflammation. Blood vessels near the surface constrict and core blood flow is defended, followed by rebound circulation. This is the basis for the swelling and soreness benefit.
• Brown fat and metabolism. Cold activates thermogenic brown adipose tissue. In men with type 2 diabetes, ten days of mild cold acclimation increased insulin sensitivity by about 43 percent. Experienced winter swimmers who combine cold dips with sauna show greater cold-induced thermogenesis than controls.
• Resilience. Repeated, voluntary exposure to a controlled stressor trains composure under stress. That is the mental side of the protocol, and the catecholamine data help explain why people report better mood and focus afterward.

The Recovery Evidence, Honestly

Cold water immersion has the deeper evidence base. A 2022 systematic review and meta-analysis of 52 studies found that cold water immersion after high-intensity exercise improved muscular power, muscle soreness, creatine kinase and perceived recovery at 24 hours. Shorter, colder exposures produced the largest effects on some markers.

Whole-body cryotherapy has strong physiological data but thinner recovery trials. A Cochrane review found too few high-quality studies to conclude it reduces muscle soreness. That reflects how little high-quality research exists so far, and the hormonal response itself is well documented.

Timing is the caveat most people miss. In a 12-week trial, men who took a 10-minute cold plunge after every strength session gained less muscle and strength than men who used active recovery. Cold blunts some of the inflammatory signaling that drives hypertrophy. When muscle growth is the goal, BIOGENEX separates cold from lifting by several hours or uses it on other days.

NEO Luna: Why We Chose This Cryochamber

Most cryotherapy units run on liquid nitrogen. The NEO Luna is fully electric. It produces dry, ultra-cold air, and with its current software the cabin reaches close to -100°F. A dedicated cabin fan adds wind chill on top of that, moving cold air across the body for the full session. There are no nitrogen deliveries, no nitrogen vapor, and no refrigerant or oil refills.

• Whole body, head included. Nitrogen chambers keep the head, neck and shoulders outside because nitrogen is not safe to breathe. The Luna is fully enclosed with breathable air, so cold reaches the face and neck too, including gentle stimulation of the vagus nerve, which helps regulate stress response and heart rate.
• Three intensity modes. Beginner uses lower fan speed for a gentler chill. Intermediate produces a faster drop in skin temperature. Expert runs maximum airflow. We progress clients through them the same way we progress a training load.
• Clear, fog-free cabin. The air is dehumidified, so there is no fog. That makes the session easier for anyone who dislikes enclosed spaces.
• Consistent cold, all day. A cold storage system holds temperature through repeated door openings, where many electric chambers lose cooling and ice up under back-to-back sessions.
• Built-in safety. CryoSafe Alert monitors entry and exit in real time and alarms if no exit is detected. Cabin lighting tracks the session, from green at ready, through light blue as the fans ramp up and dark blue for the final cold boost, back to green at completion, with red as an overexposure alert.
• Fast and dry. Two to three minutes, no wet skin, back to your day immediately. Skin must be dry, and you wear the protective gear we provide: socks, slippers, gloves and ear protection, with an optional face mask. Jewelry comes off.
• Same partner as the rest of the lab. NEO Science also builds our Hyperbaric Oxygen Therapy chamber and NEO Light, so the lab runs on one service network.

Chilly GOAT: Why We Chose This Cold Plunge

The Michael Phelps Chilly GOAT by Master Spas is a purpose-built cold tub. A dedicated chiller holds a set water temperature session after session, and continuous filtration with UV sanitation keeps the water clean between clients. App-based temperature control lets us dial exposure to the protocol rather than to the weather.

The Chilly GOAT holds any set water temperature from 39°F to 104°F, so the same tub runs a near-freezing plunge or a warm soak. Cold plunge sessions typically last 3 to 10 minutes. Water is the key difference: it conducts heat roughly 25 times faster than air, so a plunge pulls heat from the body far more deeply than a cryochamber, even at a much warmer temperature.

Head to Head: Luna vs. Chilly GOAT

Who Should Not Use Cold Therapy

Cold is a cardiovascular stressor. We screen for uncontrolled hypertension, coronary disease, recent heart attack, unstable angina and arrhythmia, blood clots, severe respiratory disease, Raynaud's phenomenon, cold urticaria and other cold sensitivity disorders, peripheral neuropathy, pregnancy, and open wounds or recent incisions before anyone enters either device.

How It Fits the BIOGENEX Protocol

Cold is assigned to the goal. Cryotherapy for fast resets and days you cannot afford to be wet or slow. Cold plunge for recovery after conditioning and for metabolic and resilience training. Both pair with the Sunlighten mPulse sauna for contrast protocols, the same heat and cold pattern studied in winter swimmers. When we stack cryotherapy with photobiomodulation, cold comes first: it triggers the endorphin, hormone and cytokine response, and the light that follows improves circulation and cellular repair. For general wellness, one to three cryotherapy sessions per week is typical. Sessions draw from APEX Lab credits.