The Claim

In nonathletic transgender men receiving testosterone therapy, muscle mass increases by approximately 10% and grip strength by 18% within the first 12 months, and physical performance in push-ups, sit-ups, and running reaches or approaches the average levels observed in cisgender men by 3 years, indicating that masculinizing hormone therapy is associated with significant improvements in strength and endurance over time.

Source: The Impact of Gender-Affirming Hormone Therapy on Physical Performance

What the research says

Roughly balanced

Support and challenge are close. The picture may shift as more studies come in.

Supports
1score
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 guys who aren't athletes gain noticeable muscle and strength in their first year on testosterone, and after about 3 years, their push-ups, sit-ups, and running get close to or match the average fitness levels of cis men.

See the scientific wording

In nonathletic transgender men undergoing testosterone therapy, muscle mass increases by approximately 10% and grip strength by 18% within the first 12 months, with physical performance in push-ups, sit-ups, and running approaching or reaching the average levels of cisgender men by 3 years, suggesting masculinizing hormone therapy is associated with significant gains in strength and endurance performance over time.

What the research says

1 study
  1. Study: The Impact of Gender-Affirming Hormone Therapy on Physical Performance

    The study looks at the same thing as the claim—how testosterone therapy affects strength and fitness in transgender men—and finds that their muscle and performance improve and become similar to cisgender men over time.

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

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