Effects Of Steroid Use And Training On Myogenic Expression In Trained Male Iron Sport Athletes

Anabolic-Androgenic Steroid (AAS) use has been shown to impact the gene expression of the myogenic growth factors insulin-like growth factor 1 (IGF1), myogenin (MYOG), and myoblast determination protein 1 (MyoD). While studies have explored this in rodent models, limited research has been conducted in human subjects, with no studies exploring athletic populations. PURPOSE: This cross-sectional study investigated the effects of AAS use and iron sport training style on myogenic expression of IGF1, MYOG, and MyoD. METHODS: Fifty-two male iron sport athletes were recruited via volunteer and snowball samping from specialized local gyms. All athletes were classified as powerlifters (n = 21), bodybuilders (n = 19), or strongman (n = 12) based on a self-reported training style questionnaire item. Participants were further stratified into AAS users (n = 18) or non-users (n = 34) via a yes/no self-reported questionnaire item; AAS users were further prompted to indicate which compounds were used and in what doses. Saliva samples were collected from each participant via passive drooling to assess expression levels of IGF1, MYOG, and MyoD via polymerase chain reaction (PCR)-derived cycle threshold (CT) values. A 2 (AAS use) x 3 (iron sport) factorial MANOVA analyzed group differences in IGF1, MYOG, and MyoD levels (⍺ = 0.05). RESULTS: There was no mean vector difference on any combination of dependent variables (V = 0.136, F(6, 88) = 1.073, p = 0.385, ηp2 = 0.068), and no significant main effects for AAS use (V = 0.145, F(3, 43) = 2.435, p = 0.078, ηp2 = 0.145), or iron sport (V = 0.168, F(6, 88) = 1.345, p = 0.246, ηp2 = 0.084). CONCLUSIONS: Neither iron sport training style nor AAS use result in differences in myogenic growth factor expression relative to each other. Future research should investigate the effects of variables such as training age, length of AAS history, or expression of myogenic inhibitors such as myostatin.