Summary: In a secondary analysis pooling three randomised trials, structured prenatal exercise blunted the gestational rise in resting maternal blood lactate seen in controls, with the clearest benefit in women with overweight or obesity, and no adverse maternal or neonatal effects.
PICO Summary
| Element | Detail |
|---|---|
| Population | Pregnant women pooled from three blinded, prospective randomised controlled trials (secondary analysis). |
| Intervention | ~24 weeks of supervised aerobic, resistance, or combination exercise between 12–16 and 37–40 weeks’ gestation. |
| Comparison | Standard prenatal care without structured exercise. |
| Outcome | Resting lactate rose 0.5 mmol/L across gestation in controls; this rise was blunted in exercisers (p=0.01). Pre-pregnancy BMI correlated with lactate in controls (R=0.20) but not exercisers. Exercisers with overweight/obesity had lower 36-week lactate (p=0.001), notably in aerobic and combination arms. |
Prenatal exercise and resting maternal lactate
Pooled RCT secondary analysis · pregnancy · 16–36 weeks
Prenatal exercise blunted the gestational rise in resting maternal lactate that controls showed, with the clearest benefit in women with overweight or obesity. Lactate is a metabolic surrogate, not a clinical outcome.
Expert Commentary
This is a physiology-focused secondary analysis, and read for what it is, it is a tidy demonstration that exercise during pregnancy keeps a marker of resting metabolism in check. The precise finding matters and is worth stating carefully: exercisers did not simply have lower lactate, rather the gestational rise that controls showed was blunted, and the effect concentrated in women with overweight or obesity. That is a coherent, biologically sensible signal pointing to better oxidative efficiency where it is most needed. My caveats are about scope. Resting lactate is a surrogate of uncertain clinical weight, not a maternal or neonatal outcome, and pooling three trials brings heterogeneity in populations and protocols. A lower lactate is not in itself something a patient feels. Can I use this with my patients? Indirectly and supportively. It adds metabolic rationale to advice I already give, that uncomplicated pregnancies benefit from regular moderate activity, around 150 minutes a week, in whatever modality the woman will sustain, with particular value in those carrying extra weight. I would not present the lactate change itself as a clinical goal, and I would want hard outcome data before going further.
References
Claiborne A, Jevtovic F, Biagioni EM, et al. The influence of prenatal exercise modes on resting maternal blood lactate. Physiol Rep. 2025;13(13):e70444. doi:10.14814/phy2.70444