From the Guidelines
For cold air exposure benefits, aim for at least 60 minutes daily, as this duration is recommended to achieve significant brown adipose tissue (BAT) activation, which can improve metabolic health, reduce inflammation, and enhance immune function 1. The optimal temperature for cold air exposure is not strictly defined but should be cool enough to stimulate BAT activation without causing shivering, with temperatures between 16°C to 19°C (60°F to 66°F) being used in various studies 1. It is essential to note that individual tolerance to cold can vary greatly, and the most effective approach might be a personalized cooling protocol that cools to a specific physiological response, rather than a fixed temperature method 1. Consistency in daily practice is crucial, and it is recommended to start with shorter durations and gradually increase exposure time as the body adapts. Cold exposure has been shown to have various health benefits, including the activation of brown adipose tissue, which burns calories to generate heat, potentially improving metabolic health, reducing inflammation, enhancing immune function, and improving mood through the release of endorphins and norepinephrine. However, safety precautions should be taken, such as avoiding extreme temperatures, listening to the body's signals, and stopping if intense discomfort or shivering occurs, especially for individuals with cardiovascular conditions, Raynaud's disease, or other health concerns, who should consult a healthcare provider before beginning cold exposure practices. While other studies suggest different durations and methods for cold application, such as 20 to 30 minutes for 3 to 4 times daily for acute injury treatment 2, the context of these recommendations differs from the goal of achieving health benefits through BAT activation. Therefore, prioritizing the most recent and highest quality study focused on BAT activation and cold exposure, the recommended daily duration of cold air exposure for health benefits is at least 60 minutes, with temperatures and individual responses being carefully considered 1.
From the Research
Recommended Daily Duration of Cold Air Exposure
The recommended daily duration of cold air exposure to achieve health benefits is not clearly established, as the existing studies have investigated various exposure durations and temperatures. However, some studies provide insights into the effects of cold air exposure on human physiology:
- A study 3 found that exposure to -5°C for more than 20 minutes can lead to serious injuries and reduced manual performance.
- Another study 4 suggested that a 2-minute whole-body cryotherapy exposure at -135°C may be the optimum exposure length, resulting in significant changes in tissue oxyhaemoglobin, deoxyhaemoglobin, tissue oxygenation index, skin temperature, and thermal sensation.
- A study on habituation of thermal sensations 5 exposed participants to cold air (10°C) for 2 hours daily for 11 days, but did not specify a recommended daily duration for health benefits.
- A review of whole-body cryotherapy 6 found very low-quality evidence for the effectiveness of cold air exposure in preventing and treating muscle soreness after exercise, with exposure durations ranging from 1 to 4 minutes.
- A study on cold air exposure during heavy exercise 7 found that 50 minutes of exposure to -15°C induced more airway symptoms and epithelial stress than rest, but did not provide a recommended daily duration for health benefits.
Key Findings
- The optimal duration of cold air exposure for health benefits is unclear and may depend on individual factors, such as temperature, exercise intensity, and health status.
- Exposure to cold air can have various effects on human physiology, including changes in skin temperature, blood pressure, and immune response.
- More research is needed to determine the recommended daily duration of cold air exposure for achieving health benefits and to fully understand the effects of cold air exposure on human physiology.