Condition category
Nutritional, Metabolic, Endocrine
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting

Plain English Summary

Not provided at time of registration

Trial website

Contact information



Primary contact

Dr Gary Scott Goldfield


Contact details

Children's Hospital of Eastern Ontario
Research Institute
K1H 8L1
+1 613 737 7600 ext. 3288

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title


Study hypothesis

Compared to children with free access to targeted sedentary behaviors, children with contingent access to sedentary behavior will exhibit greater increases in physical activity, larger reductions in sedentary behaviors, and more favorable changes in fitness, body composition, diet, and motivation to be physically active.

Ethics approval

Ethics approval received from the Children's Hospital of Eastern Ontario (CHEO) Research Ethics Board on the 11th June 2001.

Study design

Randomised controlled trial

Primary study design


Secondary study design

Randomised controlled trial

Trial setting

Not specified

Trial type

Quality of life

Patient information sheet




Intervention: Contingent Group -
The experimental (contingent) group is designed to increase child physical activity levels and decrease time spent in targeted sedentary behaviors by making access to sedentary activity contingent on physical activity. After data from activity monitors are downloaded, participants in the experimental contingent group will be told how much time they earned in each of the following two weeks for TV/VCR viewing and video games played via TV (e.g. Nintendo etc.). Parents will be taught how to program the TV allowance, which is an electronic device that records and helps budget TV/VCR viewing and video game playing. We acknowledge that targeted children may watch TV with parents or friends outside the house, or play computer games on a PC computer, and this will be measured by the concomitant use of self-report measures of sedentary activity. It is important to note that these potential sources of contamination also existed in previous clinical research that reduced access to TV viewing in obese children, and marked increases in physical activity were still obtained. Parents will be asked to implement the contingencies for two weeks beyond 12-week post-treatment to encourage physical activity between weeks 10 and 12, and this fading of contingency management may provide an opportunity for parents to implement their own contingencies.

Control: Non-Contingent group -
Participants in the non-contingent control group will also visit the laboratory bi-weekly to have their physical activity monitors downloaded. They will also be given a TV allowance for monitoring purposes (and to control for this device in the home), but parents will be explicitly told that children should have free access to targeted sedentary activities independent of physical activity. The control group is designed to control for contact with investigators, feedback on physical activity levels, passage of time, the effects of wearing the activity monitors, and the presence of the TV allowance in the home.

Intervention type



Not Specified

Drug names

Primary outcome measures

Physical activity, measured by pedometer counts.

Secondary outcome measures

1. Time in sedentary behaviour
2. Aerobic fitness (peak maximal oxygen consumption)
3. Body Mass Index (BMI)
4. Percent body fat (bioelectrical impedance and skinfold measurement)
5. Food intake and macronutrient composition
6. Motivation to be physically active (self-report)

Overall trial start date


Overall trial end date


Reason abandoned


Participant inclusion criteria

1. 8 - 12 year old children, either sex, who are overweight or obese defined as a Body Mass Index (BMI) above the 85th BMI percentile for age and sex (CDC, 2002)
2. Engaging in 15 hours of targeted sedentary behaviour per week, including TV/VCR/DVD use and video game playing
3. Engaging in less than 30 minutes of moderate to vigorous physical activity
4. No conditions that would limit physical activity
5. Agreement that the child or parent would not participate in any other exercise or weight control program during the course of the study
6. No regular participation in swimming or strength training because these activities cannot be measured properly by accelerometry
7. Willingness of the parents to enforce or maintain the contingencies or lack of as reflected by their assigned study group
8. Parent providing signed informed consent, and child providing signed informed assent

Participant type


Age group




Target number of participants


Participant exclusion criteria

Children with developmental disabilities, who are often obese, will be excluded from participating in this initial trial in order to reduce the heterogeneity of the sample.

Recruitment start date


Recruitment end date



Countries of recruitment


Trial participating centre

Children's Hospital of Eastern Ontario
Ottawa, Ontario
K1H 8L1

Sponsor information


Children's Hospital of Eastern Ontario (Canada)

Sponsor details

401 Smyth Road
K1H 8L1

Sponsor type

Not defined



Funder type

Research organisation

Funder name

Canadian Institutes of Health Research (CIHR) (Canada) - (ref: MCT-53574)

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Results - basic reporting

Publication summary

Publication citations

Additional files

Editorial Notes