Environmental dynamics of energy metabolism: The effects of ambient temperature on basal metabolism and the special benefits of winter sports
Ambient temperature is a crucial factor affecting human energy metabolism. At rest, the body's metabolic rate is most stable when the ambient temperature is between 20°C and 30°C. When the ambient temperature drops below 20°C, energy metabolism gradually increases. In very low temperatures, the body experiences shivering and increased muscle tension to maintain normal body temperature. Exercising in winter not only burns energy but also depletes energy to maintain body temperature, making it a viable option for weight loss, just like in other seasons. Studies show that the body produces more than twice as many chemicals that promote fat storage in winter as in summer. Without strict control over food intake and regular physical activity, fat is more easily accumulated in winter.
The biggest difference between summer and winter lies in the temperature. In warmer environments, fat is more easily broken down, especially in peripheral areas like the buttocks and thighs, where fat mobilization and breakdown accelerate significantly. In summer, high ambient temperatures make it difficult for the body to dissipate heat. During exercise, increased heat production coupled with limited heat loss leads to a faster and greater rise in body temperature. Research indicates that the activity of enzymes involved in fat mobilization and breakdown is related to body temperature; at higher temperatures, the activity of these enzymes is relatively higher, making fat easier to burn.
The human body burns significantly more energy during exercise in the high temperatures of summer compared to winter, under the same conditions. To achieve the same weight loss results in winter as in summer, the exercise duration must be extended accordingly. People's appetites tend to decrease in summer, which may explain why weight loss is more effective then. Although the cold weather in winter leads to a greater need for calories and a tendency to unconsciously consume more food, obese individuals can still achieve effective weight loss through exercise in winter if they strictly control their food intake and consistently engage in scientific exercise.
Adipose tissue has a relatively low blood supply, and the temperature of various organs and tissues in the body is not uniform. Except for the fat sacs around internal organs, which are slightly warmer due to the influence of surrounding organs, subcutaneous adipose tissue generally has a lower temperature, with the subcutaneous adipose tissue in the buttocks and thighs being even colder than the abdominal wall fat. Therefore, ambient temperature has a significant impact on the temperature of subcutaneous fat. Under the same exercise intensity, the effect of exercise for weight loss in winter (when ambient temperature is low) is significantly less than in summer (when ambient temperature is high). This is because of the temperature difference in subcutaneous adipose tissue, reducing abdominal fat is relatively easier during exercise, while reducing fat in the buttocks and thighs is relatively more difficult.
Because the process of fat mobilization is very complex, and at the beginning of exercise, the energy supply for skeletal muscle activity is mainly provided by the oxidation and breakdown of glycogen. The mobilization and utilization of fatty acids only gradually increase at least 20 to 30 minutes after the start of exercise. In cold winters, the mobilization and utilization of fatty acids takes even longer. Therefore, adequate warm-up exercises before exercise are crucial to improving fat utilization during exercise. Even in hot summers, warm-up exercises are necessary, and in winter, they should last at least 30 minutes.
When exercising to lose weight in winter, choose times of day when the ambient temperature is relatively high, such as after 10 am or before 4 pm, as the weight loss effect will be more obvious than at other times. Exercising indoors in a warmer environment is more effective for weight loss than exercising outdoors in a colder environment. Appropriately extending the duration of each exercise session can also improve the weight loss effect, as this ensures a higher proportion of energy is supplied by fat during exercise.
Before engaging in physical exercise in winter, a longer warm-up is necessary because the body's response to low temperatures is closely related to temperature. Patients with cardiovascular disease should perform thorough warm-up exercises in a warm environment before exercising outdoors in lower temperatures to avoid a drastic reaction to cold. It's important to stay warm during winter exercise, wearing warm and breathable clothing. If you need to reduce clothing, do so gradually after your body has warmed up sufficiently during exercise. After exercise, dry off sweat promptly or change out of damp clothes.
Winter weather is unpredictable, with frequent rain, snow, strong winds, or smog, so exercise time should be planned flexibly. If outdoor exercise is not suitable for extended periods, gyms or indoor sports facilities are good alternatives.