Exercise Rehabilitation and Multiple Weight Loss Pathways: A Review of Metabolic Protection During Cool-down Activities, Hypoxia Weight Loss Mechanisms, and Multidimensional Weight Loss Methods

A complete physical fitness exercise consists of three parts: warm-up, the main exercise, and cool-down. The various physical exercises performed after the main exercise are called cool-down activities. Cool-down activities are sometimes also called post-exercise relaxation exercises. Cool-down activities are a very important part of the exercise, sometimes even significantly affecting the effectiveness of the workout. During the cool-down, the body's functional levels need to gradually decline. Even though the intensity of exercise for weight loss is not high, a post-exercise physical exercise process is still necessary.

Its function is similar to other types of post-exercise cool-down activities: gradually reducing the large amount of blood supply to the musculoskeletal organs, promptly clearing metabolic waste products generated in the skeletal muscles, and preventing discomfort caused by sudden rest after exercise. It also encourages the continued burning of fat mobilized from fat stores during exercise. In fact, skeletal muscles continue to burn some fat during the cool-down. The intensity of the cool-down should gradually decrease, starting with dynamic activities, followed by joint mobilization, relaxation exercises, and muscle stretching. Because the intensity of the cool-down is very low, heat production begins to decrease while heat loss remains at a high level; therefore, it is advisable to wear outer clothing to keep warm during the cool-down.

Hypoxia-based weight loss refers to exercising in high-altitude or low-oxygen-pressure environments to achieve weight loss. Currently, there are two main methods: high-altitude living and low-oxygen-pressure training (living in a high-altitude or low-oxygen-pressure environment and exercising in a normal-oxygen environment at sea level) and high-altitude living and high-oxygen-pressure training (living and exercising in both high-altitude or low-oxygen-pressure environments). Studies have shown that exercising in hypoxic or high-altitude environments has significant weight loss effects. Living or training in a high-altitude, low-oxygen-pressure environment stimulates the kidneys to produce erythropoietin enzymes due to oxygen deficiency. These enzymes then prompt the liver to produce erythropoietin progenitor hormone (EPO), which is then converted into erythropoietin.

EPO can promote increased erythrocyte production in the bone marrow and stimulate hemoglobin synthesis. Increased erythrocyte count and hemoglobin levels enhance the body's oxygen transport capacity, thus significantly improving athletes' aerobic capacity. Recent research indicates that the low oxygen partial pressure environment at high altitudes stimulates increased secretion of adrenaline, noradrenaline, and glucagon. These hormones increase the activity of hormone-sensitive lipases in adipocytes, facilitating fat mobilization and utilization, thus contributing to weight loss. However, hypoxic weight loss is subject to many limitations, making it challenging for ordinary people to implement.

With social development and improved living standards, the obese population is gradually increasing, and weight loss methods are becoming more diverse. Currently, widely researched and applied weight loss methods include: exercise, dieting, medication, surgery, traditional Chinese medicine, acupuncture, and massage. Exercise primarily works by regulating the body's metabolic function, enhancing fat burning, and promoting fat oxidation and decomposition. When exercising for weight loss, it's crucial to emphasize moderate-intensity, long-duration aerobic exercise to maximize fat consumption. Dieting, on the other hand, involves restricting calorie intake to reduce the conversion of excess calories into fat, thereby controlling weight.

Drug-based weight loss methods suppress appetite, reduce nutrient absorption in the digestive tract, and increase fat breakdown. Traditional Chinese medicine (TCM) weight loss often addresses the spleen, dampness, phlegm, and blood stasis, with mechanisms including reducing exogenous lipid absorption and promoting lipid transport. Acupuncture weight loss stimulates meridians and acupoints to regulate the endocrine system and increase the basal metabolic rate. TCM massage weight loss uses manipulation techniques and stimulation of acupoints and meridians to regulate various metabolic functions and promote fat breakdown. Weight loss drugs work by suppressing appetite, reducing nutrient absorption in the digestive tract, and increasing fat breakdown. Common drugs include thyroid hormones, digoxin, phentermine, fenfluramine, and orlistat.

Weight loss drugs eliminate the need for dieting and exercise, leading to rapid weight loss, but they also carry significant risks: They are expensive, have substantial side effects, and cause severe rebound weight gain after discontinuation. Long-term use can cause loss of appetite, nausea, and diarrhea, and may even damage liver and kidney function; drug accumulation in the body can also exacerbate underlying diseases. Weight loss drugs require long-term, uninterrupted use, and rebound weight gain is highly likely upon discontinuation. To date, no weight loss drug has been found that is both effective and free of adverse reactions.