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What Is the Effect of Breast Size on Running Economy and Upper Body Biomechanical Factors Contributing to Running Economy?

PMID 40489959 (2025): what, breast — Running economy (study note for endurance athletes).

Last updated/Feb 23, 2026, 11:13 PM

Study note • PMID 40489959

What Is the Effect of Breast Size on Running Economy and Upper Body Biomechanical Factors Contributing to Running Economy?

Medicine and science in sports and exercise2025 • DOI 10.1249/MSS.0000000000003780
Evidence D54/100
Action 3: Experiment carefully

Useful, but technique/population sensitive.

ELI5

In plain language

This study investigated the effect of breast size on running economy, breast displacement, total body center of mass excursion, trunk angular velocity, and exercise-induced breast pain at different running velocities. (controlled study; recreational runners).

The abstract doesn’t indicate a clear change in Running economy under the tested conditions. Treat this as a signal, not a guarantee; confirm methods and context in the full paper.

Takeaways

What the abstract suggests

  • Study question: This study investigated the effect of breast size on running economy, breast displacement, total body center of mass excursion, trunk angular velocity, and exercise-induced breast pain at different running velocities.
  • The abstract doesn’t indicate a clear change in Running economy under the tested conditions.
  • Population: recreational runners.
  • Protocol cues (title/abstract): 10 km.

Protocol

Protocol (as reported)

  • Intervention/exposure: what, breast (vs comparison group).
  • Dose/time/duration cues in abstract/title: 10 km.
  • Outcomes: Running economy.
  • Replication note: abstracts often omit adherence and timing; confirm details before changing training or supplementation.

Fit

Who it helps, and who should skip it

Who it helps

  • Athletes similar to the study population (recreational runners) working on biomechanics.
  • Athletes who can measure Running economy with a repeatable workout or time-trial effort.

Who should skip

  • If you have symptoms or conditions that make the intervention risky, get professional guidance.
  • If you’re near race day and can’t safely test, defer the experiment.

Methods

What the study actually did

  • Design: controlled study.
  • Population: recreational runners.
  • Comparator: comparison group.
  • Outcomes measured: Running economy.
  • Protocol cues mentioned: 10 km.
  • Source: PubMed PMID 40489959 (2025) — Medicine and science in sports and exercise.

Results excerpt

What the abstract reports

Women with large breast volumes experience significantly more breast motion compared with their smaller breasted counterparts during running, despite the presence of a high-support sports bra.

Note: excerpts are short; for full context, read the paper.

Limits

Limitations & bias

  • Abstract-only summaries can miss critical details (population, protocol, adherence, and context).
  • Single studies often don’t generalize to your event, history, and training load; treat results as a starting point.
  • If your context differs (elite vs recreational; cycling vs running), adjust expectations and be conservative.
  • This is performance information, not medical advice.

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Sources