She is not only talking from expertise, she takes these hormones herself
A systematic review of 11 studies published in MDPI in 2021 concluded that L-Carnitine may help improve high-intensity exercise performance, reduce muscle fatigue and support recovery, especially when taken at 34 g about an hour before exercise or as a long-term supplement (22.72 g per day for 924 weeks) with carbohydrates
doi:10.1056/NEJMoa2301972 Coskun T, Urva S, Roell WC, Qu H, Loghin C, Moyers JS, O'Farrell LS, Briere DA, Sloop KW, Thomas MK, Pirro V, Wainscott DB, Willard FS, Abernathy M, Morford L, Du Y, Benson C, Gimeno RE, Haupt A, Milicevic Z
It works synergistically with TRT and creatine