Changes in body composition among female athletes using a levonorgestrel-releasing intrauterine system in preparation for the Paris 2024 Paralympic Games: an exploratory study

Introduction: Body composition assessments play a crucial role in athletic performance, as lean mass (LM) is linked to improved training outcomes and competitive success.Many athletes use hormonal contraception to manage or suppress menstruation, but some studies suggest that oral contraceptive may affect body composition.The levonorgestrel-releasing intrauterine device (LNG-IUD), a progestin derived from 19-nortestosterone, has been associated with increases in fat-free mass.Given its potential impact on body composition, this study aimed to evaluate the effects of LNG-IUD use on Paralympic athletes preparing for the Paris 2024 Paralympic Games.Material and methods: A prospective, descriptive study was conducted over one year with 10 Paralympic athletes who chose a 19.5 mg levonorgestrel intrauterine device as their contraceptive method for the Paris 2024 Games.Body composition was assessed using the DXA Lunar Prodigy Advance before the insertion of the IUD and one year after its use.The variables analyzed were fat mass, lean mass, body fat percentage, lean mass percentage, and bone mass.Results: The average age was 233 years; three athletes had intellectual disabilities, three had visual impairments and four physical disabilities.After one year using the hormonal intrauterine device, lean tissue mass increased from 40.9 kg to 41.8 kg, (p < 0.04).Fat mass decreased from 15.0 kg to 14.4 kg, (p = 0.14).Bone mineral density increased from 1.25g/cm 2 to 1.26g/cm 2 (p = 0.46).Conclusions: The 19.5 mg LNG-IUD was associated with increased lean tissue mass in athletes, suggesting potential benefits for body composition in preparation for the Paris 2024 Paralympic Games.