Thermogenesis is the process by which the body produces heat. This is not just about keeping warm, it’s a metabolically active process that influences how our body burns calories, regulates temperature and maintains energy balance.
Thermogenesis plays a role in fat metabolism, body weight regulation and even immune defense. As part of a healthy metabolism, it contributes to our body’s ability to stay lean, manage blood sugar and respond to environmental stress. Supporting it is increasingly recognized as a strategy for longevity, metabolic health and healthy body composition.
How thermogenesis works in the body
It happens when r body converts stored energy (usually from fat or food) into heat. This occurs through several mechanisms:
- Mitochondria in cells (especially in brown fat) convert energy substrates into heat rather than ATP;
- The sympathetic nervous system activates thermogenic responses, especially in response to cold;
- Thyroid hormones stimulate metabolism and promote heat production.
In simple terms, it is how our body “burns calories for heat” and it happens all the time, both at rest and during activity.
Types of thermogenesis
There are several types of thermogenesis, each with different triggers and metabolic outcomes:
- Basal thermogenesis: this is the baseline heat production that keeps our body functioning at rest. It accounts for the majority of our daily energy expenditure;
- Exercise induced thermogenesis: physical activity generates heat as muscles contract and expend energy. The more intense the activity, the greater the thermogenic effect;
- Diet-induced thermogenesis (DIT): also called the thermic effect of food, this refers to the energy used for digestion, absorption and nutrient processing, especially after eating protein-rich meals;
- Non-shivering thermogenesis: this occurs mainly in brown adipose tissue (BAT) and is activated by cold exposure. It increases metabolic rate without requiring muscle activity (shivering), making it a unique and efficient form of heat production.
Thermogenesis and metabolic health
Thermogenesis plays a key role in energy balance and influences several markers of metabolic health:
- Increases total calorie expenditure, helping with weight control;
- Enhances fat oxidation, especially in cold or fasted states;
- Improves blood glucose regulation by increasing insulin sensitivity;
- Supports healthy lipid metabolism, lowering triglycerides and improving HDL.
A sluggish thermogenic response is associated with obesity, insulin resistance and poor metabolic flexibility.
Thermogenesis and aging
Thermogenic capacity tends to decline with age due to:
- Loss of brown fat activity;
- Reduced muscle mass;
- Impaired thyroid and mitochondrial function.
This contributes to age related issues such as:
- Lower energy expenditure and gradual fat gain;
- Weaker cold tolerance and thermoregulation;
- Slower metabolic adaptation to stress.
Preserving thermogenesis is important for maintaining metabolic vitality, body composition and resilience in older age.
How to boost thermogenesis naturally
There are several evidence-based strategies to stimulate and maintain it:
Cold exposure
- Cold showers, ice baths or time outdoors in cool temperatures activate brown fat;
- Triggers non-shivering thermogenesis and increases mitochondrial efficiency.
Physical activity
- High-intensity interval training (HIIT) and resistance training both raise resting metabolic rate;
- Exercise improves muscle mass, which supports basal thermogenesis.
Thermogenic foods and compounds
- Capsaicin (from chili peppers), ginger, green tea extract and caffeine stimulate metabolic heat;
- These act through sympathetic nervous system pathways to enhance fat burning.
Support hormonal and mitochondrial health
- Ensure optimal thyroid function, as thyroid hormones directly regulate it;
- Sleep, protein intake and stress management help balance hormones and energy regulation.
Thermogenesis is more than just heat, it’s a metabolic function with deep ties to energy balance, fat metabolism and cellular health. As part of a longevity strategy, supporting it can help us stay leaner, stronger, more energized and more metabolically resilient as we age.
By combining cold exposure, thermogenic nutrients, movement and hormonal support, we can enhance this natural process and unlock its benefits for long term vitality.
