This study aims to evaluate the effects of a supervised whole-body high-intensity interval training (WB-HIIT) program on physical fitness and health outcomes in adults with overweight and obesity. WB-HIIT is a practical and time-efficient training modality based on body-weight exercises performed at high intensity with short recovery intervals. It may offer an accessible approach for improving health in individuals with excess body weight.
Participants aged 18 to 55 years with a body mass index (BMI) between 25 and 35 kg/m² will take part in a supervised 10-week WB-HIIT program, performed in small groups and led by trained exercise professionals. Before and after the intervention, participants will undergo assessments including DXA-based body composition analysis, fasting blood sampling, muscular strength testing, a Chester step test, a maximal graded treadmill exercise test with gas-exchange analysis to determine VO₂peak, and functional evaluations (chair-stand, arm-curl, and 6-minute walk test). Physical activity and dietary intake will also be recorded.
The primary objective of the study is to assess whether WB-HIIT improves cardiorespiratory fitness (VO₂peak) in adults with overweight. Secondary objectives include evaluating changes in muscular strength, body composition, metabolic markers, and functional capacity.
The results may help determine whether an equipment-free WB-HIIT program can serve as an effective and accessible training approach for improving health and physical fitness in adults with overweight and obesity.
Adults aged 18 to 55 years.
Body mass index (BMI) between 25 and 35 kg/m².
Able to provide written informed consent.
Able to safely participate in high-intensity interval training.
BMI < 25 or > 35 kg/m².
Presence of any chronic medical condition other than overweight/obesity.
Known cardiovascular, metabolic, respiratory, or musculoskeletal disease that contraindicates high-intensity exercise.
Pregnancy.
Parallel
Whole-Body High-Intensity Interval Training (WB-HIIT)
BehavioralA structured WB-HIIT program using body-weight exercises such as squats, lunges, mountain climbers, and similar multi-joint movements. Sessions last 35-50 minutes and include 3 to 4 sets of interval blocks performed at high intensity. The training is supervised by qualified exercise professionals.
Peak oxygen consumption (VO₂peak)
Peak oxygen consumption (VO₂peak) will be measured during a maximal graded treadmill exercise test with gas analysis to assess changes in cardiorespiratory fitness following the 10-week WB-HIIT program. VO₂peak will be expressed in mL·kg-¹·min-¹.
Muscular strength
Maximal dynamic strength will be assessed using 3-repetition maximum (3-RM) tests on the leg press and bench press.
Estimated VO₂max from the Chester Step Test
Cardiorespiratory fitness will also be estimated using the Chester Step Test to evaluate submaximal aerobic capacity.
Body composition
Total and segmental (i.e., arms, legs and trunk) body fat mass, lean mass, and visceral fat will be assessed using dual-energy X-ray absorptiometry (DXA). They will all be expressed in kg.
Muscular endurance (fatigue tests at 60% 1-RM)
Muscular endurance will be evaluated by recording the number of repetitions performed at 60% of the estimated 1-RM for leg press and bench press.
Functional performance (chair-stand test)
Lower-body function will be assessed using the 30-second chair-stand test.
Click on the lead sponsor to view all of their trials.
