REF-1745 · Rasmussen, Bisgaard & Hansen, 2026 · International Journal of Sports Physiology and Performance, · Paper · PubMed

In female football players, evidence on menstrual-cycle phase and performance was inconsistent: of 15 small prospective observational studies (210 players), 5 found aerobic or sprint performance lower in the early follicular phase than in the late follicular or mid-luteal phase and 10 found no difference, with no consistent effect on agility, jumps or change of direction

A count of study results without pooling, in studies whose phase verification was inconsistent

Main caveat: Observational within-player studies, small samples (about 14 per study), counted rather than pooled; no effect sizes in the abstract.
limited evidenceMeasured on trained to highly trained athletesRead from the abstract only

Rasmussen, Bisgaard and Hansen reviewed studies of eumenorrheic female football players that measured performance in two or more defined menstrual-cycle phases. Searching PubMed and SPORTDiscus up to January 2026, they found 15 prospective observational studies with 210 players in total.

They sorted outcomes into three domains: aerobic (for example total running distance and Yo-Yo tests), sprinting and high-intensity running, and agility and jump power (for example jumps and change of direction), and compared phases domain by domain without pooling.

Ten studies found no phase differences; five reported lower aerobic and/or sprint performance in the early follicular phase than in the late follicular or mid-luteal phase; agility and power outcomes showed no consistent phase effect.

The authors list small samples, inconsistent phase verification and varied performance tests as weaknesses across studies, conclude that aerobic and sprint performance may be slightly impaired early in the follicular phase but that the evidence is inconclusive, and call for standardised protocols with hormonal confirmation of phase.

Participants

15 studies, 210 eumenorrheic female football players in total (about 14 per study by our arithmetic).
Not in the abstract: ages, playing level, how eumenorrhea was defined, and whether hormonal contraceptive users were explicitly excluded (the eumenorrheic label implies naturally cycling players, but the abstract does not say).

Protocol

Search: PubMed and SPORTDiscus, PRISMA, last updated January 2026; not registered.
Inclusion: eumenorrheic female football players; at least one quantitative performance outcome assessed across two or more defined phases.
Outcome domains: aerobic performance (total running distance, Yo-Yo tests and similar), sprint and high-intensity running, agility and power-related outcomes (jumps, change of direction).
Quality: a modified version of an existing quality tool, covering methodological quality and how phase was verified; ratings not in the abstract.
Synthesis: structured comparison by domain across phases; no meta-analysis.
Not in the abstract: which phases each study compared, how phases were determined in each (day counting, ovulation tests, blood hormones), the size of any differences, and funding.

Key Results

DomainFinding across the 15 studies
Aerobic and/or sprint performance5 studies: lower in the early follicular phase than in the late follicular or mid-luteal phase; 10 studies: no phase differences
Agility and power (jumps, change of direction)no consistent phase effect
Methodological weaknesses (the authors)small samples, inconsistent phase verification, varied performance tests
No magnitudes, effect sizes or confidence intervals are given in the abstract.

Practical Application

Phase gave no consistent signal for a player's performance: 5 of 15 small studies in female footballers found lower aerobic or sprint performance in the early follicular phase and 10 found no difference, a count of results rather than a pooled size, so a small early-follicular dip is neither shown nor ruled out; jumps and change of direction showed no consistent effect. This supports SYNTH-37's default not to restructure training by phase; the early-follicular dip matches the trivial early-follicular reduction in REF-335 rather than contesting it.
How phase was tested matters for reading this review: the players were eumenorrheic, but phase verification was inconsistent across studies and the authors themselves ask for hormonal confirmation, so a study that counted days may have compared phases that were not what they were labelled. The review cannot say whether the 5 positive studies were the better- or worse-verified ones.
Inference, not tested here: if a player feels flat early in her cycle, ask about symptoms (pain, heavy bleeding, sleep) and act on those, as SYNTH-37 says; heavy bleeding is a reason to check iron (REF-573).
Not settled by this design: how large the early-follicular dip is, whether it shows in matches rather than tests, and whether it applies to contraceptive users or to endurance athletes.

Limitations

Observational within-player studies, small samples (about 14 per study), counted rather than pooled; no effect sizes in the abstract.
Phase verification inconsistent across studies; the quality ratings and how they relate to the positive findings are not in the abstract.
Two databases only; not registered.
Football-specific tests (running distance, Yo-Yo) do not transfer one-to-one to endurance performance.
Written from the abstract and the PubMed record; full text not read; risk of bias not read.
How this entry was checked and changed
Why this level

risk of bias not read (abstract only): the abstract names the main weaknesses (small samples, inconsistent phase verification, varied tests) but gives no ratings; held below the B+ cap because the included studies are observational within-player comparisons rather than controlled trials, results are counted rather than pooled, and the review was not registered