Guided exercise intervention for improving physical fitness and weight control in overweight and obese males and females

INTERVENTION: Phase I (6‐week intervention): Group 1 ‐ exercise follows guidance from a wrist computer: subjects will follow the daily guidance of the device to exercise (Nordic break walking) 30 minutes to 1 hour each time and gradually increase the intensity and duration. The intensity of exercise will be checked every 2nd week and the guidance will be modified accordingly. Group 2 ‐ general training advice but no device: subjects will follow the instruction by a researcher to exercise (Nordic break walking) 30 minutes to 1 hour a time and gradually increase the intensity and duration. Group 3 ‐ weight control follows guidance from a wrist computer: subjects follow the weight guidance from device to change their weight either by eating or exercise. The weight (body composition) will be checked every 2nd week and the guidance will be modified accordingly. Group 4 ‐ weight control gets general advice but no device: subjects follow the instruction by a nutritionist to change their weight either by eating or exercise. After the first phase of the study, subjects will not be informed that they will be followed‐up for phase II of the study. Thus it can be ensured that the maintenance rate is not interfered with by the participants knowing that they will be followed later. In study phase II (1‐year intervention), all of the subjects will be invited back 6 months after the onset of the phase I study. A wrist computer will be provided to them and subjects will follow the instruction to set the exercise intensity/duration and target weight on the basis of their fitness level and weight to exercise. Those people who are not maintaining their leisure time physical activity (LTPA) will be randomly assigned to two groups. One group will have and one will not have 6 months measurements. Phone call tracking interview will be contacted every 3 months interval to evaluate the maintenance rate. CONDITION: Overweight/obesity ; Nutritional, Metabolic, Endocrine ; Obesity PRIMARY OUTCOME: Efficacy of guided exercise on fitness and weight control: physical fitness and body composition (HRV, gut microbiota, Max VO2, fat mass, lean mass) ‐; 1. Daily physical activity and a diet diary will be assessed at baseline, every week during the intervention, at follow‐up point 2, and every week during the long term intervention until follow‐up point 3; 2. Anthropometry and blood pressure will be measured at baseline, half‐way through the long‐term intervention and at follow‐up points 1, 2 and 3. Blood samples will also be taken at this point.; 3. Body composition, and the 10‐metre walking test will be measured at baseline and every two weeks through the short term intervention until follow‐up point 1, and at follow‐up point 2, halfway‐way through the long term intervention and at follow‐up point 3. The treadmill test will also be taken at all of these points apart from follow‐up point 3.; 4. Faecal samples, basal metabolic rate and max VO2 will be measured at baseline and follow‐up points 1, 2 and 3 SECONDARY OUTCOME: Maintenance of exercise and weight control intervention:; 1. How many people will maintain their physical activity and weight control after a short intervention?; 2. What are the reasons for people stopping exercise and weight control after a short intervention?; 3. Does long‐term guided exercise and weight control intervention help to maintain peoples LTPA and weight control after intervention? INCLUSION CRITERIA: 1. Women and men aged 20 ‐ 50 years 2. Physically inactive (regular exercise less than or equal to two times per week and less than or equal to 45 minutes per session) 3. Body mass index (BMI) greater than 25 kg/m^2 ? 38 kg/m^2