Childhood Obesity, Obesity & Overweight
Conditions
Keywords
childhood obesity, inspiratory muscle training, high-intensity interval training, aerobic fitness, exercise-related metabolic health, functional exercise capacity, six-minute walk test, diaphragm thickness
Brief summary
Childhood obesity is associated with reduced cardiorespiratory fitness, impaired exercise tolerance, and altered respiratory mechanics. This randomized controlled trial investigated whether combining inspiratory muscle training with functional high-intensity interval training improves diaphragm morphology, respiratory muscle strength, pulmonary function, aerobic fitness, and functional exercise capacity in boys with obesity. Fifty boys aged 10-12 years were randomly assigned to six weeks of combined inspiratory muscle training and functional high-intensity interval training or usual activity.
Detailed description
This prospective, two-arm, randomized controlled trial investigated the effects of a six-week combined inspiratory muscle training and functional high-intensity interval training program in boys aged 10-12 years with obesity. Fifty participants were randomly allocated in a 1:1 ratio to either a combined training group or a usual-activity control group. The intervention consisted of progressive inspiratory muscle training performed five days per week and functional high-intensity interval training performed three non-consecutive days per week for six weeks. Inspiratory muscle training was performed using a threshold pressure-loading device. Training commenced at 30% of maximal inspiratory pressure and increased by 5% each week, reaching 55% of maximal inspiratory pressure in week 6. Each session consisted of two sets of 30 inspiratory efforts. Functional high-intensity interval training was performed three times per week. Each approximately 35-40-minute session consisted of a standardized warm-up, a functional high-intensity interval circuit, and a cool-down. The circuit included wall sit, incline push-up, seated knee-to-chest exercise, shadow boxing, Superman exercise, and low-step-up exercise. Training intensity was progressively increased by manipulating work-to-rest ratios and circuit volume. The control group continued habitual daily activities without participating in structured exercise or respiratory muscle training during the six-week study period. Primary outcomes were diaphragm thickening fraction, inspiratory diaphragm thickness, and expiratory diaphragm thickness. Secondary outcomes included maximal inspiratory pressure, maximal expiratory pressure, forced vital capacity, forced expiratory volume in one second, FEV₁/FVC ratio, six-minute walk distance, estimated VO₂max, body composition, and perceived exertion. Assessments were performed at baseline and after the six-week intervention under standardized laboratory conditions between 15:00 and 17:00. Diaphragm ultrasonography was performed by a radiologist blinded to group allocation
Interventions
OTHERInspiratory Muscle Training
Inspiratory muscle training was performed using a threshold pressure-loading device (POWERbreathe). Participants trained once daily, five days per week, for six consecutive weeks. Each session consisted of two sets of 30 inspiratory efforts. Training began at 30% of maximal inspiratory pressure in week 1, with the training load progressively increased by 5% each week to reach 55% of maximal inspiratory pressure in week 6. Training pressure was reassessed weekly, and all sessions were supervised by a certified exercise specialist.
OTHERFunctional High-Intensity Interval Training
Functional high-intensity interval training was performed three times per week on non-consecutive days for six weeks. Each session lasted approximately 35-40 minutes and consisted of an approximately 8-minute warm-up, a functional high-intensity interval circuit, and an approximately 5-minute cool-down. The circuit included wall sit, incline push-up, seated knee-to-chest exercise, shadow boxing, Superman exercise, and low-step-up exercise. Training intensity was progressively increased by manipulating work-to-rest ratios and the number of circuit cycles. Perceived exertion was monitored using the Borg CR-10 scale.
Sponsors
Gümüşhane Universıty
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
SUPPORTIVE_CARE
Masking
SINGLE (Outcomes Assessor)
Masking description
Outcome assessors were blinded to group allocation whenever feasible. The radiologist responsible for diaphragm ultrasonography was blinded to group allocation throughout the study. Participants and exercise intervention personnel were not blinded because of the nature of the behavioral exercise interventions.
Intervention model description
Participants were randomly allocated in a 1:1 ratio to either a combined inspiratory muscle training and functional high-intensity interval training group or a usual-activity control group.
Eligibility
Sex/Gender
MALE
Age
10 Years to 12 Years
Healthy volunteers
Yes
Inclusion criteria
* Male sex. * Age 10-12 years. \*Obesity according to World Health Organization age- and sex-specific BMI reference criteria. * No regular participation in structured exercise training during the preceding six months. * Medical clearance to participate in moderate-to-vigorous physical activity.
Exclusion criteria
* Diagnosed cardiovascular, neuromuscular, orthopaedic, or metabolic conditions that could interfere with exercise participation. * Chronic respiratory disease, including asthma requiring regular medication. * Impaired pulmonary function defined as FEV₁/FVC \<75%. \*Upper respiratory tract infection within the preceding two weeks. * Medication use that could affect respiratory function or exercise capacity. * Previous thoracic surgery. * Inability to complete the testing procedures.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Inspiratory Diaphragm Thickness | 6 weeks | Inspiratory diaphragm thickness (DTins) was measured by ultrasound at the end of maximal inspiration at the zone of apposition of the right hemidiaphragm. Three measurements were obtained and averaged. The measurement represents an ultrasound-derived index of diaphragm morphology. |
| Diaphragm Thickening Fraction | 6 weeks | Diaphragm thickening fraction (DTf) was assessed using diaphragm ultrasonography and calculated as \[(end-inspiratory diaphragm thickness - end-expiratory diaphragm thickness) / end-expiratory diaphragm thickness\] × 100. Measurements were obtained from the right hemidiaphragm at the zone of apposition. Three measurements were obtained in each respiratory phase and averaged for analysis. |
| Expiratory Diaphragm Thickness | 6 week | Expiratory diaphragm thickness (DTexp) was measured by ultrasound at the end of maximal expiration at the zone of apposition of the right hemidiaphragm. Three measurements were obtained and averaged. The measurement represents an ultrasound-derived index of diaphragm morphology. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Height | 6 Week | Body composition was assessed using a multi-frequency bioelectrical impedance analyzer. Height was assessed according to standardized procedures. |
| Weight | 6 Week | Body composition was assessed using a multi-frequency bioelectrical impedance analyzer. Weight was assessed according to standardized procedures. |
| Maximal Inspiratory Pressure | 6 week | Maximal inspiratory pressure (MIP) was measured using a handheld mouth pressure meter according to ATS/ERS recommendations. Measurements were performed from residual volume, and the best reproducible values were recorded in cmH₂O. |
| Maximal Expiratory Pressure | 6 week | Maximal expiratory pressure (MEP) was measured using a handheld mouth pressure meter according to ATS/ERS recommendations. Measurements were performed from total lung capacity, and the best reproducible values were recorded in cmH₂O. |
| Estimated VO2max | 6 week | Estimated maximal oxygen uptake (VO₂max) was calculated from six-minute walk distance and body mass index using the validated prediction equation developed for children and adolescents with obesity: VO₂max = 26.9 + (0.014 × 6MWD \[m\]) - (0.38 × BMI \[kg/m²\]). VO₂max values were estimated and were not directly measured by cardiopulmonary exercise testing. |
| Forced Expiratory Volume in One Second | 6 week | Forced expiratory volume in one second (FEV₁) was measured using spirometry according to ATS/ERS recommendations. |
| FEV₁/FVC Ratio | 6 week | The FEV₁/FVC ratio was calculated from spirometric measurements obtained according to ATS/ERS recommendations. |
| Six-Minute Walk Distance | 6 week | Functional exercise capacity was assessed using the Six-Minute Walk Test. Participants walked for six minutes along a pre-measured, flat, straight corridor at a self-selected comfortable pace. The total distance covered in meters was recorded. |
| Forced Vital Capacity | 6 week | Forced vital capacity (FVC) was measured using spirometry according to ATS/ERS recommendations. |
| Body Mass Index | 6 week | Body composition was assessed using a multi-frequency bioelectrical impedance analyzer. Body mass index (BMI) and BMI z-score were assessed according to standardized procedures. |
| Rating of Perceived Exertion | 6 week | Perceived exercise intensity was assessed using the Borg Category Ratio-10 Rating of Perceived Exertion scale. Participants were familiarized with the scale before the intervention, and RPE was recorded immediately after each functional HIIT session throughout the six-week intervention period. |
Countries
Turkey (Türkiye)
Contacts
CONTACTCoşkun Yılmaz, Associate professor
Outcome results
None listed