Obesity
Conditions
Brief summary
Exercise has been shown to offer numerous health benefits and be particularly important in preventing weight gain or regain for people with obesity. Exercise guidelines can be difficult to interpret and apply independently and do not address specific exercise limitations in individuals with obesity. The exercise monitoring system proposed in this study might provide a new method to meet aerobic exercise guidelines independently with reduced risk of injury. The exercise monitoring system controls, in real-time, the intensity of an exercise session consisting of treadmill walking. During treadmill walking, the exercise monitoring system will instruct participants to increase or decrease how much participants raise their knees and swing their arms while maintaining a smooth contact with the ground, based on real-time readings of the participants' heart rate. In this clinical trial, each participant will perform a control and an experimental training session. Both training sessions will include four blocks of 7 minutes of treadmill walking alternated with three periods of rest (3 min). In the control session, participants will monitor the intensity of exercise independently using a standard heart rate monitor and control it by adjusting their walking speed. In the experimental session, each participant will follow the exercise monitoring system instructions displayed on a TV, and treadmill walking speed will be set at a comfortable walking speed. Target heart rates of 60% HRR will be used as the exercise intensities in both training sessions. The investigators will examine energy expenditure, heart rate, and kinematic measures under control and experimental conditions. The goals of this clinical trial are to determine the effect of exercising with the exercise monitoring system in individuals with obesity. The investigators hypothesized that the experimental session will result in higher total energy cost and efficiency than the control session; and in lower heart rate error, tibial positive peak accelerations and feedback errors than the control session. The results of this study will inform proposals for larger interventions that will focus on 1) testing different types of obesity and osteoarthritis, 2) adding a resistance-training component, and 3) integrating a diet intervention.
Interventions
DEVICEVisual feedback monitoring system (HFFS)
Participants will follow the exercise monitoring system's instructions displayed on a TV. Treadmill walking speed will be set at a comfortable walking speed.
OTHERControl
Participants will monitor the intensity of exercise independently using a standard heart rate monitor and control it by adjusting the treadmill speed (walking speed).
Sponsors
University of Mississippi Medical Center
Study design
Allocation
NON_RANDOMIZED
Intervention model
SINGLE_GROUP
Primary purpose
PREVENTION
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
20 Years to 45 Years
Healthy volunteers
No
Inclusion criteria
* BMI ≥ 30.0 kg/m2 and ≤ 40.0 kg/m2 * Age 20 to 45 years; * Able to understand spoken English at the level needed to: * understand and follow instructions for equipment setup, testing, and task performance * answer questions related to effort and preference * be able to understand consent document and provide informed assent
Exclusion criteria
* Any signs or symptoms suggestive of cardiovascular, pulmonary, metabolic, or renal disease. * Any injury or health condition that affects the ability to walk on a treadmill.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Energy Expenditure (Oxygen Consumption) | 1 Day | Energy expenditure was evaluated from oxygen consumption (ml/kg/min) measured during the exercise and recovery bouts using a breath-by-breath portable metabolic analyzer (K5, COSMED, Rome, Italy). |
| Heart Rate (Bpm) | 1 day | Average heart rate (bpm) during steady state period of exercise. |
| Percentage of Strides With Tibia Peak Positive Accelerations Above 3g | 1 day | — |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Mean Tibial Positive Peak Acceleration | Up to 4 weeks | Tibia axial accelerations were calculated using an IMU (Xsens Technologies BV, Enschede, Netherlands) aligned in the long axis of the participant's tibia attached to the anteromedial aspect of the distal tibia using double-sided adhesive tape. The mean peak positive acceleration (PPA) was calculated as the mean tibia PPA across all recorded strides for both sides during the exercise above 3g. |
| Heart Rate Error | 1 day | Heart rate error (HRerr) was calculated as the absolute error between the target heart rate (HRtarget) and the actual heart rate during the steady state exercise. HRtarget corresponded to 60% heart rate reserve (HRR) of each participant. HRR was calculated as the difference between the estimated maximal heart rate and the resting heart rate. Maximal heart rate was estimated using the 220-age formula, and resting heart rate was measured using the heart rate monitor after at least 4 min of seated rest at the beginning of each session. |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| All Study Participants All participants were randomized to receive all interventions:
Visual feedback monitoring system (HFFS): Participants will follow the exercise monitoring system's instructions displayed on a TV. Treadmill walking speed will be set at a comfortable walking speed.
Control: Participants will monitor the intensity of exercise independently using a standard heart rate monitor and control it by adjusting the treadmill speed (walking speed). | 20 |
| Total | 20 |
Baseline characteristics
| Characteristic | All Study Participants |
|---|---|
| Age, Continuous | 24.3 years STANDARD_DEVIATION 4.9 |
| Ethnicity (NIH/OMB) Hispanic or Latino | 2 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 18 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants |
| Race (NIH/OMB) Black or African American | 7 Participants |
| Race (NIH/OMB) More than one race | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants |
| Race (NIH/OMB) White | 13 Participants |
| Region of Enrollment United States | 20 participants |
| Sex: Female, Male Female | 8 Participants |
| Sex: Female, Male Male | 12 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 20 | 0 / 20 |
| other Total, other adverse events | 0 / 20 | 0 / 20 |
| serious Total, serious adverse events | 0 / 20 | 0 / 20 |
Outcome results
Primary
Energy Expenditure (Oxygen Consumption)
Energy expenditure was evaluated from oxygen consumption (ml/kg/min) measured during the exercise and recovery bouts using a breath-by-breath portable metabolic analyzer (K5, COSMED, Rome, Italy).
Time frame: 1 Day
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| HFFS | Energy Expenditure (Oxygen Consumption) | 20.2 ml/kg/min | Standard Deviation 5.8 |
| Control | Energy Expenditure (Oxygen Consumption) | 22.8 ml/kg/min | Standard Deviation 6.1 |
Primary
Heart Rate (Bpm)
Average heart rate (bpm) during steady state period of exercise.
Time frame: 1 day
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| HFFS | Heart Rate (Bpm) | 149 bpm | Standard Deviation 4.5 |
| Control | Heart Rate (Bpm) | 151 bpm | Standard Deviation 3.8 |
Primary
Percentage of Strides With Tibia Peak Positive Accelerations Above 3g
Time frame: 1 day
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| HFFS | Percentage of Strides With Tibia Peak Positive Accelerations Above 3g | 23.8 % of strides | Standard Deviation 27.6 |
| Control | Percentage of Strides With Tibia Peak Positive Accelerations Above 3g | 54.0 % of strides | Standard Deviation 31 |
Secondary
Heart Rate Error
Heart rate error (HRerr) was calculated as the absolute error between the target heart rate (HRtarget) and the actual heart rate during the steady state exercise. HRtarget corresponded to 60% heart rate reserve (HRR) of each participant. HRR was calculated as the difference between the estimated maximal heart rate and the resting heart rate. Maximal heart rate was estimated using the 220-age formula, and resting heart rate was measured using the heart rate monitor after at least 4 min of seated rest at the beginning of each session.
Time frame: 1 day
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| HFFS | Heart Rate Error | 3.3 bpm | Standard Deviation 2 |
| Control | Heart Rate Error | 2.8 bpm | Standard Deviation 1.5 |
Secondary
Mean Tibial Positive Peak Acceleration
Tibia axial accelerations were calculated using an IMU (Xsens Technologies BV, Enschede, Netherlands) aligned in the long axis of the participant's tibia attached to the anteromedial aspect of the distal tibia using double-sided adhesive tape. The mean peak positive acceleration (PPA) was calculated as the mean tibia PPA across all recorded strides for both sides during the exercise above 3g.
Time frame: Up to 4 weeks
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| HFFS | Mean Tibial Positive Peak Acceleration | 3.5 g | Standard Deviation 0.2 |
| Control | Mean Tibial Positive Peak Acceleration | 4.0 g | Standard Deviation 0.9 |