Exercise therapy for obesity combined with osteoarthritis and hyperlipidemia: A practical guide from joint protection to lipid regulation

Osteoarthritis, also known as osteoarthritis or degenerative arthritis, is the most common bone and joint disease among middle-aged and elderly people. It frequently occurs in the knee, hip, lumbar spine, and cervical spine, with the knee being the most frequently affected joint. Statistics show that the incidence of osteoarthritis in people over 55 years of age ranges from 44% to 70%. The clinical manifestations of osteoarthritis include joint pain and impaired motor function. Currently, most treatments only address the pain and there is no truly satisfactory method.

Medication can relieve pain, but its effect on improving motor function is limited. Joint replacement surgery can improve motor function and pain in patients with advanced osteoarthritis, but it may lead to various complications. Therefore, rehabilitation treatment for osteoarthritis is very important. Exercise therapy can reduce movement disorders caused by osteoarthritis and is easily adapted and accepted by patients. Obese patients with osteoarthritis urgently need to lose weight to reduce pressure on the joints and improve their osteoarthritis condition due to the adverse effect of their body weight on joint load.

Exercise plays a positive role in the treatment of osteoarthritis. The articular cartilage is nourished by synovial fluid. During joint movement, the joint compresses and relaxes the cartilage. During compression, fluid leaks out from the cartilage matrix; during relaxation, synovial fluid enters the matrix. This repeated alternation promotes cartilage metabolism, providing nutrients to chondrocytes and removing metabolic waste. Exercise also promotes blood circulation throughout the body and in the joint, which is beneficial for reducing inflammation. Furthermore, exercise stimulates chondrocytes, promotes the synthesis of collagen and hexosaccharides, increases the range of motion of the joint, and restores joint function.

Increasing bone stress stimulates bone growth and increases bone density, preventing osteoporosis in patients. Simultaneously, maintaining good physical function can further prevent secondary joint damage. When obese patients with osteoarthritis undergo exercise for weight loss, we should first fully consider their physical condition before developing an exercise prescription, and then adopt different exercise methods accordingly.

Aerobic exercise: During the acute phase of joint swelling and pain, activity should be reduced. After the inflammation subsides, swimming, elliptical training, walking, and Tai Chi can be performed. However, brisk walking is not recommended for patients with unstable joints. Swimming is the most suitable exercise for obese patients with osteoarthritis because the buoyancy of water reduces the load on the joints, and swimming strengthens the muscles around the joints. Moderate to low-intensity aerobic exercise can achieve good weight loss results and improve osteoarthritis symptoms.

Muscle strengthening exercises: For patients with significant swelling and pain during the acute phase of osteoarthritis, isometric exercises, including isometric contraction exercises of the quadriceps femoris, can be used. During the chronic phase, multi-point isotonic exercises are used to dynamically strengthen the muscles around the joint at different angles. Joint range of motion training: Because osteoarthritis patients have limited joint mobility, they need to undergo exercises to increase joint range of motion under the guidance of a rehabilitation physician.

Obese individuals, due to their excessive weight, place a significantly greater load on their joints than those of normal weight. Therefore, obese patients, especially those with severe obesity, often develop osteoarthritis. When obese patients with osteoarthritis engage in exercise for weight loss, they should consider their physical condition and choose exercises that are easy to maintain, of moderate intensity, and low in stress on the joints. Even severely obese patients without obvious osteoarthritis should choose appropriate exercises for weight loss to avoid excessive stress on their joints.

Hyperlipidemia refers to a condition where the concentration of lipids in the blood exceeds the normal range; specifically, triglyceride, total cholesterol, and low-density lipoprotein (LDL) levels are elevated and exceed the normal range, while high-density lipoprotein (HDL) levels are below normal. Hyperlipidemia can cause significant damage to various organs and the cardiovascular system. It can be divided into primary and secondary types. Primary hyperlipidemia is related to genetic factors, while secondary hyperlipidemia is often associated with metabolic disorders, endocrine diseases (such as obesity, diabetes, myxedema, hypothyroidism, and hyperadrenocorticism), hypertension, and liver and kidney diseases.

Obese patients with hyperlipidemia must undergo a comprehensive medical examination, physical fitness test, and exercise stress test before starting exercise for weight loss. Since plasma lipids mainly originate from food, obese patients with hyperlipidemia especially need to control their diet. The basal metabolic rate is calculated based on the physical examination results, and the daily energy expenditure is calculated with reference to the exercise stress test results to develop a personalized nutritional plan. Special attention should be paid to controlling lipid intake, which should be approximately 10%–15% of total daily calories. During exercise for weight loss, it is important to maintain a normal nitrogen balance, but the amount should not be excessive.

Regarding exercise, people with high blood lipids who want to lower their blood lipids through exercise should participate in longer-duration fat-burning exercises such as swimming, brisk walking, jogging, and cycling. For people with high blood lipids, the most suitable exercise program is one with low intensity and long duration, ensuring the body uses more aerobic oxidation for energy. Each exercise session should last 60-120 minutes. Excessive intensity or duration may cause injury, while insufficient intensity or short duration will have little effect on blood lipids.

Long-term aerobic exercise can lower blood lipids, especially in reducing total cholesterol and LDL cholesterol while increasing HDL cholesterol, thus protecting blood vessel walls and significantly preventing the formation of atherosclerotic plaques. Numerous studies have confirmed that moderate-intensity, long-duration aerobic exercise leads to a decrease in blood triglyceride, cholesterol, and LDL levels, while increasing the HDL/LDL ratio, significantly improving lipid metabolism. This decrease in blood lipid levels consequently reduces the incidence and mortality of cardiovascular disease.