Changes in physical fitness in transgender adolescents receiving gender-affirming hormone therapy: protocol for a prospective cohort pilot study

There is very little data about the physical fitness of transgender and gender-diverse (TGD) youth. This protocol paper describes the methods for a pilot study that aims to measure changes in fitness levels in TGD adolescents undergoing gender-affirming hormone therapy (GAHT) using FitnessGram, a reliable, validated tool used to measure physical fitness. A secondary aim of the study is to compare the physical fitness of TGD adolescents with normative data for cisgender individuals. This will be a prospective cohort study. We will recruit 25 TGD participants who are 13-18 years old and patients in our organisation's Gender Development Clinic, planning to initiate GAHT. Participants will complete FitnessGram before starting GAHT and undergo repeat assessments 6 months and 12 months after GAHT initiation. Participants will also complete the Physical Activity Questionnaire for Adolescents. We plan to report changes in the participant's ability to achieve the FitnessGram standards over 12 months. Secondary outcomes will include a comparison of the achievement of the FitnessGram standards in the cohort with the reported achievement of standards for cisgender adolescents.