Effects of 8 Weeks of Level and Uphill Walking on Balance and Physical Function in Middle-Aged Women with Obesity

INTERVENTION: Behavioral : Twenty‐two middle‐aged women with a body fat percentage of =30% were randomly assigned to either the flat treadmill waling group (FTG, n=11) or the inclined treadmill walking group (ITG, n=11). Both groups performed treadmill walking 5 days per week for 8 weeks, with a target energy expenditure of 300 kcal per session. Exercise intensity was prescribed at a moderate level corresponding to 40–60% of heart rate reserve (HRR). Heart rate was continuously monitored using a wireless heart rate monitor (POLAR Electro Oy, Kempele, Finland) throughout each exercise session. The FTG performed treadmill walking at a 0% incline throughout the 8‐week intervention. Walking speed was not fixed but was individually adjusted according to each participant's cardiorespiratory fitness to maintain the target intensity of 40–60% HRR. Exercise continued until the participant reached the target energy expenditure of 300 kcal for each session. The ITG followed the same exercise frequency, duration, target intensity, and energy expenditure as the FTG but performed treadmill walking with a progressively increasing incline. The initial incline was set at 3% to ensure safety and facilitate adaptation and was increased by 1% each week, up to a maximum of 10%. Accordingly, the incline was set at 3%, 4%, 5%, 6%, 7%, 8%, 9%, and 10% from weeks 1 through 8, respectively. In the ITG, treadmill incline itself was not used as the primary indicator of exercise intensity. Instead, exercise intensity was individually regulated based on heart rate. If heart rate exceeded the target range of 40–60% HRR as the incline increased, walking speed was reduced to maintain moderate exercise intensity. Conversely, walking speed was adjusted when necessary to maintain the prescribed HRR range. In both groups, heart rate was continuously monitored, and walking speed was immediately adjusted if heart rate deviated from the target range. Thus, exercise frequency (5 days/week), intervention duration (8 weeks), relative exercise intensity (40–60% HRR), and target exercise volume (300 kcal/session) were matched between the two groups. The primary difference between the interventions was the treadmill incline: the FTG maintained a 0% incline throughout the intervention, whereas the ITG progressed from a 3% to a maximum 10% incline. By individually adjusting walking speed while maintaining comparable relative exercise intensity and target energy expenditure between groups, the study was designed to evaluate the differential effects of treadmill inclination on the study outcomes. CONDITION: Endocrine, nutritional and metabolic diseases PRIMARY OUTCOME: Core muscular stability is assessed using the McGill core endurance test, including trunk flexor endurance (TFE), trunk extensor endurance (TEE), and left and right trunk lateral endurance (TLE‐L and TLE‐R). Functional movement is assessed using the Functional Movement Screen (FMS). Lower extremity strength is assessed using the Leg Press, Leg Extension, and Leg Curl tests. Static balance is assessed using the Balance Error Scoring System (BESS), and dynamic balance is assessed using the Y‐Balance Test (YBT). SECONDARY OUTCOME: Low back disability is assessed using the Korean Oswestry Disability Inde X(KODI). INCLUSION CRITERIA: Participants were eligible for inclusion in this study if they met all of the following criteria: ‐ Middle‐aged women aged 40–59 years ‐ Body fat percentage =30% ‐ No participation in a regular exercise program within the previous 6 months ‐ Able to walk independently and perform activities of daily living, with no medical restrictions that would preclude participation in moderate‐intensity treadmill walking exercise ‐ Able to participate continuously in the assigned flat or inclined treadmill walking program throughout the 8‐week intervention period ‐ Agreed not to participate in any other regular exercise program during the study period ‐ Able to understand the study purpose and procedures, exercise intervention, assessment procedures, and the potential risks and benefits associated with participation ‐ Voluntarily agreed to participate in the study and provided written informed consent Before enrollment, all potential