What is contrast therapy?
Contrast therapy is the deliberate alternation between heat and cold, typically infrared sauna and cold plunge, within a single session. The back-and-forth opens blood vessels in the heat and tightens them in the cold, which gets your circulation moving and leaves most people feeling refreshed.
It's not about tolerating heat or cold independently. The swing between the two is what makes it feel so different from either one alone.
The cardiovascular pump effect
Heat dilates blood vessels and drives blood to the periphery. Cold contracts them and pushes blood back toward the core. When you alternate between heat and cold repeatedly, you create a kind of pump: blood vessels open and tighten again and again, moving blood through your muscles.
Think of it like squeezing and releasing a sponge. Each heat-to-cold change moves blood through again.
Lymphatic drainage
Unlike the cardiovascular system, the lymphatic system has no pump of its own. It relies on body movement, compression, and, critically, thermal changes to drive fluid through lymphatic vessels. Changes in temperature are one of the things that help move it along.
Many people say their legs feel lighter and less heavy after hard training.
Hormetic adaptation: why stress makes you stronger
Hormesis is the biological principle that controlled, moderate stress produces a stronger adaptation response than no stress at all. Cold exposure is a hormetic stressor. Heat is a hormetic stressor. The combination, delivered in a controlled, repeating pattern, produces a compounding adaptation signal.
With regular sessions, most people find the heat and cold get easier, and many say other stresses feel easier to handle too.
Why athletes love it
Soreness after training is normal. Athletes use heat and cold together because it covers both sides: the heat helps you loosen up, and the cold helps you feel fresh. Many say contrast therapy is their favorite way to recover after a hard week.
Mental resilience and parasympathetic recovery
Contrast therapy works the nervous system as much as it works the body. Transitioning from heat to cold requires deliberate regulation of the stress response: slowing the breath, resisting the urge to exit, staying present. That neural practice has real-world carryover. Clients consistently report improvements in stress response, sleep quality, and emotional regulation with regular contrast therapy.
The cold component also produces the sustained dopamine elevation associated with cold water immersion, meaning the mood and focus benefits extend well beyond the session.
The protocol: timing and structure
A common starting point is about three times as long in the heat as in the cold. For example, 15 minutes in the infrared sauna, then 3 to 6 minutes in the cold plunge, repeated two or three times. This is a guideline, not a rule. The optimal protocol depends on the individual's cold tolerance, training status, and recovery goals.
At Biohack, our team will help you dial in the right protocol for your specific situation. The session itself is 45 or 60 minutes, giving you enough time to complete multiple full cycles and experience the cumulative effect rather than just a single transition.
Many people like to end on cold: you leave feeling awake and refreshed instead of sleepy from the heat.
Contrast therapy at Biohack Cryo + Wellness
The contrast therapy room at Biohack is private. Infrared sauna and cold plunge in the same space, available to you alone for the duration of your session. No strangers sharing your cold tub. No waiting for the sauna to open up. Sessions are 45 or 60 minutes, staff-guided, and designed to deliver the full protocol rather than a single pass.
Contrast therapy is Biohack's most complete recovery offering. It combines the deep warmth of our infrared sauna with the energizing cold plunge. For extra recovery in the same visit, many clients add Compression Therapy.
Book your contrast therapy session in Woodland Hills
Biohack Cryo + Wellness is at 5305 Topanga Canyon Blvd, Woodland Hills, CA, central to the San Fernando Valley, serving Calabasas, West Hills, Tarzana, Encino, Chatsworth, Thousand Oaks, and Malibu. See our hours and directions.
Contrast therapy is the protocol most clients wish they'd started sooner. Book your contrast therapy session now and see what deliberate hot-cold recovery actually feels like.