NCT06918795 · Children's Hospital of Philadelphia
Fontan Fitness Trial
What this study is about
The goal of this randomly assigned control trial is to learn about physical fitness and exercise habits in children aged 10-17 with the Fontan Circulation through a home-based, digital exercise intervention.
View original scientific description
The goal of this randomized control trial is to learn about physical fitness and exercise habits in children aged 10-17 with the Fontan Circulation through a home-based, digital exercise intervention. The main questions it aims to answer are: * Does a home-based, digital intervention increase physical activity (PA) in youth with the FC compared to enhanced usual care? * Does a home-based, digital intervention increase physical fitness in youth with the FC compared to enhanced usual care? * Do multi-level factors (medical, neurodevelopmental, sociodemographic, neighborhood) impact the effectiveness of the digital intervention? Researchers will compare participants in the enhanced usual care arm to those in the exercise intervention arm to see if the digital intervention is effective. All participants will wear a PA tracker for 12 months and complete testing at baseline, 6 months, and 12 months.
Interventions
BEHAVIORAL
Digital Exercise Intervention
Subjects randomized to the intervention arm will receive the same as the enhanced usual care arm but will be additionally exposed to: (1) personalized plans for aerobic-based PA, (2) personalized resistance exercise sessions, and (3) financial and non-financial engagement strategies. These intervention components will be delivered continuously using an advanced digital health informatics platform during the 6 months of the intervention. The intervention will be overseen and supplemented by the exercise physiologist, who will meet with participants on a weekly, then biweekly and finally monthly basis over 6 months.
Primary outcome measures
MIMS-units
Time frame: 0 to 12 months. Evaluated from baseline to 6 months, baseline to 12 months, and 6 to 12 months.
Change in total volume of physical activity (PA) operationalized as a Monitor Independent Movement Summary (MIMS) units, expressed as a percentile based on what is expected for their age and sex.
Absolute peak VO2
Time frame: 0 to 12 months. Evaluated from baseline to 6 months, baseline to 12 months, and 6 to 12 months.
Change in absolute peak VO2, the maximum amount of oxygen the body consumes during exercise without regard to body weight (liters/minute).
Percent predicted peak VO2
Time frame: 0 to 12 months. Evaluated from baseline to 6 months, baseline to 12 months, and 6 to 12 months.
Change in percent predicted peak VO2, the maximum amount of oxygen the body consumes during exercise expressed as a percentage of what is expected for their age and sex.
Leg lean mass
Time frame: 0 to 12 months. Evaluated from baseline to 6 months, baseline to 12 months, and 6 to 12 months.
Change in leg lean mass presented as a z-score. Leg lean mass z-score compares an individual's leg muscle mass to the average for their age and sex, with values below -2.0 indicating lower-than-expected muscle mass.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Fontan Circulation present
- Girls ≥11 years of age or menstruating must have negative urine pregnancy test
- Neurodevelopmental capacity to complete all study procedures
- Physical capacity to complete all study procedures
- English speaking with at least one English speaking parent/guardian
- To enroll in the randomized control trial, percent predicted peak VO2 \<80% of age-sex matched normal controls on the baseline exercise stress test (EST)
Exclusion criteria
- Inability to complete an EST at any time (i.e. limited physical or executive function)
- Uncontrolled lymphatic disorders
- Uncontrolled noncardiac conditions
- Exercise induced or uncontrolled arrhythmias
- Pacemaker or internal cardiac defibrillator (ICD)
- Peak VO2 \<45% age-sex predicted
- Having had or under consideration for a heart transplant
- Pregnant or lactating females
- Parents/guardians or subjects who, in the opinion of the investigator, may be non-compliant with study schedules or procedures
Where
- Philadelphia, Pennsylvania
Collaborators
National Heart, Lung, and Blood Institute (NHLBI), University of Pennsylvania
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Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Apr 13, 2026 · Source of record for eligibility and locations