Infrared Sauna vs Cold Plunge: Which Should You Do First?

If you have access to both an infrared sauna and a cold plunge — as members and guests at Labs Fitness in Shoreditch do — the natural question is how to use them most effectively. Should you go heat first, then cold? Cold first, then heat? Or does the order not matter? The answer depends on what you are trying to achieve, and the physiology behind each modality gives you a clear framework for deciding.

An infrared sauna uses radiant heat to raise core body temperature from the inside out — different from a traditional steam sauna, which heats the surrounding air. The infrared approach penetrates more deeply into muscle tissue, accelerating circulation, promoting the release of heat shock proteins, and easing the residual tension that builds in muscles after training. Sessions typically last 15 to 25 minutes, at temperatures considerably lower than a Finnish sauna but with deeper physiological effect.

Cold water immersion triggers a very different physiological response. Exposure to cold causes peripheral vasoconstriction: blood vessels near the skin's surface constrict sharply, redirecting blood toward the body's core. This reduces acute inflammation and flushes metabolic by-products from exercised tissue. When you exit the cold, rapid vasodilation follows — a flood of oxygenated blood back to the periphery that accelerates recovery. The neurological effects include a sustained elevation in noradrenaline and dopamine that produces the famous post-cold mental clarity.

Used in sequence, heat and cold create what is called contrast therapy. The alternating vasoconstriction and vasodilation essentially pump the circulatory system, improving the delivery of nutrients and the clearance of waste products from muscle tissue more efficiently than either stimulus alone. This is the principle behind the classic Nordic ritual of moving between a wood-burning sauna and a cold lake — and the research base for its effectiveness in athletic recovery is now substantial.

For post-training recovery, the established protocol is sauna first, cold plunge second. After a training session, the infrared sauna loosens muscle tissue, raises circulation, and begins the recovery process by bringing heat and blood flow to the areas that have worked hardest. The cold plunge that follows locks in the benefits by driving down inflammation and triggering the vasodilation effect. You finish alert, clear-headed, and with DOMS noticeably reduced compared to a day where you used neither.

For mental clarity and energy — if you are using the suite as a standalone session on a rest day or at the start of a working day — cold first can be the better choice. Cold exposure is a powerful activating stimulus: it raises heart rate, sharpens focus, and produces the noradrenaline spike quickly. Following it with a short infrared sauna session then brings you to a calm, focused state that many people find ideal for the working hours that follow.

The temperature of the Labs Fitness cold plunge is maintained at between 8 and 12 degrees Celsius, which is within the range used in most sports recovery research. Sessions of two to four minutes are sufficient to trigger the full physiological response without unnecessary discomfort. Acclimatisation across several uses makes each session progressively more manageable — most first-time users find that by their third or fourth session, they stay in comfortably for four minutes where they initially lasted 90 seconds.

Timing within your training week also matters. Research on strength training and cold water immersion has found that cold exposure immediately after a strength session may attenuate some hypertrophic signalling — essentially interfering with the growth stimulus by cooling it down too quickly. If building maximum muscle mass is your primary goal, using the cold plunge on rest days or several hours after your strength session minimises this concern while preserving the recovery benefits.

For the majority of users — people pursuing general fitness, body composition, and health rather than specialised strength competition — this distinction is not something to worry about practically. The recovery, inflammation reduction, and mental health benefits of consistent contrast therapy outweigh the marginal concern about hypertrophy signalling for most people in most circumstances.

The recovery suite at Labs Fitness is available to Peak Plus members as part of their membership and to non-members as a standalone booking. Sessions can be reserved for the sauna and cold plunge together, giving you private access to both for a session at a time that suits you. Contact us through the website to find out more about standalone recovery bookings or to enquire about Peak Plus membership.