Recruiting

Exercise & Breastmilk

Sponsor:

Joslin Diabetes Center

Code:

NCT07467694

Conditions

Childhood Obesity Prevention

Childhood Obesity

Physical Activity

Lactation

Breastfeeding

Eligibility Criteria

Sex: Female

Age: 18 - 45

Healthy Volunteers: Accepted

Interventions

Active group

Study Details

Brief summary:

The purpose of this study is to learn how exercise and physical activity during pregnancy and after pregnancy may affect the composition of breastmilk. Certain changes in breast milk after exercise may have an impact on how infants use energy. Understanding this process may improve public health recommendations for exercise during and after pregnancy. This study can help investigators learn more about how maternal exercise patterns may affect body growth and obesity risk in infants who are breastfed. This research may help identify how different factors can influence healthy weight and early development in infants.

Conditions

Childhood Obesity Prevention

Childhood Obesity

Physical Activity

Lactation

Breastfeeding

Study ID

NCT07467694

Start date

Dec 1, 2025

Status verified date

Mar, 2026

Completion date

Jul 1, 2030

Anticipated

Primary completion date

Jul 1, 2030

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: Female

Age: 18 - 45

Healthy Volunteers: Accepted

Inclusion Criteria:

  • 18-45 y of age at the time of enrollment
  • Pre-gravid or first trimester BMI 18.5 -40 kg/m2
  • Uncomplicated singleton pregnancy
  • Intention to exclusively breastfeed for >3 months and, if parity >1, that they successfully breastfed a previous pregnancy
  • Term pregnancy (gestational age 37 to <42 weeks)
  • Infant with birth weight >10th percentile of weight for gestational age

Exclusion Criteria:

  • Any obstetric contra-indication to exercise at 1 month
  • Diagnosis of uncontrolled (HbA1c >7%) type 1 or type 2 diabetes, or gestational diabetes managed with insulin
  • Intrauterine growth restriction
  • Pre-eclampsia or other pregnancy complications
  • Alcohol, cannabis or tobacco use
  • Known congenital metabolic, endocrine disease, or congenital illness affecting infant feeding/growth
  • Major fetal anomalies
  • Musculoskeletal issues that would make exercise difficult

Study Design

Enrollment

200 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Prevention

Interventions and Outcome Measures

Arms

experimental: Enhanced physical activity

Participants in this group will be encouraged to engage in daily physical activity

no intervention: Control group

Usual care

Interventions

Active group

For participants randomized to the Active group, there will be weekly phone calls with study staff during which step counts and exercise bouts from the previous week will be reviewed, and exercise goals for the following week will be gradually increased.

Primary outcome measure

  • Altered breast milk lipidome [ Time Frame: 8 weeks ]
  • Altered breast milk metabolome [ Time Frame: 8 weeks ]

Central Contacts and Locations

Central contacts

Elvira M Isganaitis, MD, MPH

617-309-4554elvira.isganaitis@joslin.harvard.edu

Study Coordinator

857-289-3455PeaBaBy@joslin.harvard.edu

Locations

Joslin Diabetes Center

Recruiting

Boston, Massachusetts, United States, 02215

Contacts

Elvira Isganaitis, MD

elvira.isganaitis@joslin.harvard.edu

Oklahoma University College of Medicine

Recruiting

Oklahoma City, Oklahoma, United States, 73104

Contacts

Katy Duncan

katy-duncan@ou.edu

Principal Investigator:

David Fields, PhD

More Information

Sponsor

Joslin Diabetes Center

Last update posted

Mar 12, 2026

Last verified

Mar, 2026

Keywords

  • Lactation
  • Breastfeeding
  • Breast milk
  • Pregnancy
  • Exercise

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Joslin Diabetes Center on 2026-03-12.