The Development and Clinical Evaluation of Weight Loss Exercise Prescriptions: A Scientific Intervention Guideline Based on the FITT-VP Principle

An exercise prescription is an individualized physical activity plan developed based on an assessment of an individual's exercise capacity. The concept of exercise prescription was proposed in the 1950s, adopted by the WHO in the late 1960s, and is now widely accepted. The basic principle of exercise prescription is the FITT-VP principle, which includes four basic elements of physical activity (FITT: frequency, intensity, timing, and type) and two elements: volume and progress. The FITT-VP principle determines the characteristics and health benefits of exercise intervention. The progress of exercise depends on the purpose of the intervention, the individual's health condition, and fitness level. In other words, it involves adjusting the time and intensity of each of the above exercise elements during the intervention to avoid related exercise risks and achieve the expected exercise goals. The development of an exercise prescription is primarily based on physical fitness. Physical fitness refers to the body's ability to have sufficient energy and vitality to perform daily tasks without feeling overly fatigued, and also to have sufficient energy to enjoy leisure activities and cope with unexpected events. Physical fitness is further divided into exercise fitness and health fitness. Health fitness mainly includes cardiorespiratory endurance, muscle strength and endurance, flexibility, and body composition. The development of an exercise prescription includes routine pre-exercise physical examinations, health screenings and assessments, exercise testing (when necessary), setting exercise volume and content goals, medical supervision of exercise training and adjustments to the exercise plan, and prevention of sports injuries.

Routine physical examinations before exercise training include medical history, blood pressure, pulse, joint examinations, etc., and, if necessary, electrocardiograms, chest X-rays, and laboratory tests. The main purpose is to reduce the risk of exercise-related illnesses or even accidental injuries caused by inappropriate exercise.

Pre-exercise health screening and assessment: All individuals should undergo health screening and assessment (including exercise habits and levels) before starting exercise training to determine the necessity of pre-exercise testing and medical supervision. Key assessment methods include: the currently recommended Physical Activity Readiness Questionnaire (PAR-Q); assessment and classification of cardiovascular and cerebrovascular disease risk factors; recommendations for risk stratification-based medical examinations, exercise testing, and medical supervision; and evaluation of past physical activity levels.

Exercise testing encompasses two main categories: health fitness assessments and clinical exercise testing. Health fitness assessments evaluate an individual's health and functional capabilities. Each indicator can be tested using appropriate techniques and equipment tailored to the individual's characteristics. Clinical exercise testing primarily provides diagnostic and prognostic information for patients with cardiovascular disease by evaluating hemodynamics, electrocardiograms, and gas exchange and ventilation responses.

Develop exercise goals and plans (1) General principles: A suitable exercise prescription should be able to comprehensively promote physical fitness, that is, improve cardiorespiratory endurance, muscle strength and endurance, flexibility, body composition, etc. (2) Basic contents of exercise prescription: The contents generally include aerobic exercise, muscle strength training and flexibility activities, emphasizing the combination of exercise training with occupational, transportation, housework and leisure activities in daily life. Among them, the recommended goal for aerobic exercise is to accumulate at least 150 minutes per week; the recommended goal for muscle strength training is 23 days a week, 15-20 minutes each time. In terms of progress, it is emphasized to do what you can and proceed step by step. The basic components of a specific exercise training session include: Warm-up: at least 5-10 minutes, low to moderate intensity cardiorespiratory and muscle endurance activities, to the point of slight sweating; Stretching: at least 10 minutes of stretching activities after the warm-up activities; Training content: at least 20-60 minutes, a combination of aerobic exercise, resistance exercise and other exercises; Cool-down: at least 5-10 minutes, low to moderate intensity cardiorespiratory and muscle endurance activities.

Medical supervision of exercise (1) Physical load and exercise response: Exercise fatigue, recovery and adaptation are the three key links of the body's exercise response. Measuring and analyzing these changes can further determine the potential health benefits and the risk of accidental injury. (2) Adjustment of exercise plan: To prevent exercise intolerance and the chronic damage that may result, it is necessary to make timely judgments on exercise response and adjust the activity volume target, exercise intensity, time and frequency accordingly. (3) Reassessment of health status and exercise capacity: For individual specific circumstances, it is necessary to reassess health status and exercise capacity regularly. Exercise prescription and principles for weight loss: For ordinary healthy adults, the recommended physical activity to promote health and maintain weight is 150 minutes of moderate-intensity physical activity or 75 minutes of vigorous-intensity physical activity per week, or a combination of both; resistance exercise 23 days a week; and reduction of sedentary behavior time. The goal of exercise intervention for patients with simple obesity is to increase energy consumption, reduce and control weight, maintain and increase lean body mass, change body composition distribution, reduce abdominal fat, and improve circulatory, respiratory and metabolic regulation functions. The FITT (Firmware and Exercise Therapy) recommendations for exercise prescriptions place greater emphasis on frequency (at least 5 times per week), with a total exercise target of 300 minutes of moderate-intensity exercise or 150 minutes of vigorous-intensity exercise per week. Weight loss goals should be realistic, with a recommended target of 5%–10% weight loss over 36 months. The specific recommendations for the FITT-VP (Vibration and Weight Loss) principles in exercise prescriptions for weight loss are as follows:

Aerobic exercise: (1) Frequency: ≥5 days of moderate-intensity exercise per week, or ≥3 days of vigorous-intensity exercise per week. (2) Intensity: Gradually increase from low to medium intensity to medium and high intensity. (3) Time: 60 minutes of moderate-intensity exercise per day, with each session lasting at least 10 minutes, for a total of 300 minutes per week. (4) Exercise volume: 300 minutes of moderate-intensity exercise per week, or ≥1000 MET-min per week, or at least 10,000 steps at a moderate pace or higher per day. (5) Exercise type: Rhythmic aerobic exercise involving large muscle groups, requiring low skill, and at least moderate intensity. (6) Progress: Generally, during the first 46 weeks of the plan, increase the duration of each training session by 5-10 minutes every 12 weeks.

Resistance training: (1) Frequency: Train each major muscle group 23 days a week, with at least 48 hours between training sessions. (2) Intensity: Moderate intensity, at least 1 set per session, 10-15 repetitions per set. (3) Type: Multi-joint exercises are recommended. (4) Recommended number of repetitions: 24 sets per muscle group, 8-12 repetitions per set, with 2-3 minutes of rest between sets.

Flexibility training: (1) Frequency: 2-3 days a week. (2) Intensity: Stretch until you feel tightness or slight discomfort. (3) Time: Most people hold static stretches for 10-30 seconds. (4) Method: Slowly stretch large muscle groups. (5) Pattern: Repeat each flexibility exercise 24 times. Precautions: It is recommended to consult a doctor for a systematic evaluation before starting physical activity. Obesity or being overweight is a risk factor for sports injuries. For those who are particularly overweight, more protective measures are needed when starting exercise. Cycling, swimming and other sports involve less weight-bearing on the lower limb joints, so the risk is relatively low. The principle of energy balance should be followed. It is difficult to achieve the expected goal by simply relying on exercise to lose weight. It must be combined with dietary control. The weight loss speed should not be too fast. A weight loss of 0.51 kg per week is more appropriate. It is important to establish a long-term weight loss plan. Diet and exercise behavior should be adjusted according to changes in the situation.

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