The Claim

Resistance training with a one-repetition maximum up to 50 lbs in pregnant recreational athletes has no detrimental effect on placental blood flow as measured by vascular flow index (VFI) and may result in a slight increase in VFI, challenging the notion that the Valsalva maneuver during lifting universally impairs fetal perfusion.

Source: Resistance Training Does Not Decrease Placental Blood Flow During Valsalva Maneuver: A Novel Use of 3D Doppler Power Flow Ultrasonography

What the research says

Supports is higher

Support is ahead, but a single strong opposing study can change this.

Supports
47score
Challenges
0score

These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.

How it works
1 study reviewed
In plain English

Lifting weights up to 50 pounds while pregnant doesn't hurt blood flow to the baby—and might even help it a little—so the idea that lifting is always dangerous for the baby might not be true.

See the scientific wording

Resistance training up to a 50 lb one-repetition maximum (1RM) in pregnant recreational athletes does not reduce placental blood flow, as measured by vascular flow index (VFI), and may even slightly increase it, challenging the assumption that the Valsalva maneuver during lifting universally compromises fetal perfusion.

What the research says

1 study
  1. Study: Resistance Training Does Not Decrease Placental Blood Flow During Valsalva Maneuver: A Novel Use of 3D Doppler Power Flow Ultrasonography

    This study found that pregnant women who lifted weights up to 50 pounds didn’t reduce blood flow to the baby—in fact, it slightly increased. So, lifting heavy weights isn’t as dangerous for the baby as people thought.

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies

Fit Body Science verdict — we translate health claims into clear verdicts backed by peer-reviewed research.

Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.