The Claim

In transgender women athletes, gender-affirming hormone therapy leads to greater performance decrements in longer-duration endurance events (>240 seconds) compared to shorter-duration anaerobic events (<120 seconds), with race time increases of 15.8% versus 10.3%, respectively, indicating a relatively greater impact on aerobic endurance than anaerobic power.

Source: Longitudinal Performance Changes in Transgender Women Athletes Pre and Post Gender Affirming Hormone Therapy

What the research says

Supports is higher

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

Supports
44score
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.

Quantitative
1 study reviewed
In plain English

Trans women athletes tend to slow down more in long races after hormone therapy than in short sprints—suggesting endurance is affected more than quick bursts of power.

See the scientific wording

Performance decrements in transgender women athletes following gender-affirming hormone therapy are greater in longer-duration events (>240 seconds) compared to shorter-duration events (<120 seconds), with race time increases of 15.8% vs 10.3% respectively, suggesting that aerobic endurance is more affected than anaerobic power.

What the research says

1 study
  1. Study: Longitudinal Performance Changes in Transgender Women Athletes Pre and Post Gender Affirming Hormone Therapy

    The study found that transgender women athletes had bigger drops in performance in longer races than in shorter ones after hormone therapy, which matches the claim.

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

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