How exercising in hot versus cool conditions affects breast milk amount and makeup
The Impact of Acute Exercise in the Heat on Breast Milk Production and Composition in Lactating Women
This project will test if a 60-minute moderate workout in hot versus cool conditions changes how much breast milk you make and what’s in it for mothers breastfeeding infants aged 6 weeks to 24 months.
Quick facts
| Phase | Not applicable |
|---|---|
| Study type | Interventional |
| Enrollment | 10 (estimated) |
| Ages | 18 Years to 45 Years |
| Sex | Female |
| Sponsor | Providence College Academic / other |
| Drugs / interventions | cart |
| Locations | 1 site (Providence, Rhode Island) |
| Trial ID | NCT07036640 on ClinicalTrials.gov |
What this trial studies
This randomized crossover trial has lactating participants complete baseline testing and two exercise visits: one 60-minute bout at 40% VO2peak in a hot environment (36°C, 40% RH) and one in a thermoneutral environment (20°C, 20% RH). Participants will record total 24-hour breast milk production using an infant scale and provide samples for milk composition and energy-density analysis. Baseline measures include body composition by DXA, anthropometrics, hydration and metabolic heat production testing. All data collection occurs at the Health and Human Performance Laboratory at Providence College.
Who should consider this trial
Good fit: Ideal candidates are healthy breastfeeding or pumping mothers aged 18–45 whose infants are 6 weeks to 24 months old and who delivered at term (37–42 weeks).
Not a fit: People with recent obstetrical complications, multiple gestation, chronic diseases (e.g., diabetes, hypertension), a recent heat illness, or who fall outside the age/postpartum window are unlikely to qualify or benefit from this protocol.
Why it matters
Potential benefit: If successful, the results could help breastfeeding mothers and clinicians give clear guidance about exercising in hot conditions to protect milk supply and nutrition.
How similar studies have performed: Some prior work suggests moderate exercise alone does not strongly reduce milk volume or alter composition, but the specific effects of exercising under heat stress are largely untested.
Eligibility criteria
Show full inclusion / exclusion criteria
Inclusion Criteria: * Currently breastfeeding or pumping expressed breastmilk for their 6-week to 24-month infants * Aged 18-45 years old * Delivered their infants between 37-42 weeks of gestational age Exclusion Criteria: * Obsterical complications during pregnancy * multiple gestation * Chronic disease (i.e., diabetes, hypertension, metabolic disease) * Heat illnness in the last 3 month
Where this trial is running
Providence, Rhode Island
- Providence College — Providence, Rhode Island, United States (Recruiting)
Study contacts
- Principal investigator: Margaret C Morrissey-Basler, PhD — Providence College
- Study coordinator: Margaret C Morrissey-Basler, PhD
- Email: mmorri17@providence.edu
- Phone: 4018650219
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.