Direct Questioning: Age, ethnicity, height, weight
Boys were asked to indicate all of the sports that they are involved in. Options included: soccer, basketball, swimming, Australian Football, Cross Country, Hockey, Athletics, and ‘other (please specify)
The 10-item Appearance subscale of the Body Esteem Scale for Adolescents and Adults  was used to assess body esteem. Cronbach’s alpha for the current study was acceptable α = .63
Drive for Muscularity
The 7-item Beliefs Subscale of the Drive for Muscularity Scale  was used to assess Drive for Muscularity. Previous research has confirmed that only the beliefs subscale, not the muscularity attitudes subscale predicts supplement use  Cronbach’s alpha for the current study was high α = .99
Use of Protein Powder, creatine, and anabolic steroids
Direct questioning items from ATLAS evaluation studies [32, 33] included: “Have you ever used (protein powder/creatine/anabolic steroids)” and participants responded by selecting an option from ‘I don’t know what this is’, ‘no, never’, ‘yes, once or twice’, or ‘yes, more than three times’.
Intentions to use protein powder, creatine, and anabolic steroids
Items from ATLAS evaluation studies [32, 33] asked participants to indicate the degree to which they agree or disagree (on a 7-point response scale) with the statements ‘I intend to try or use (protein powder/creatine/anabolic steroids)’.
Direct questioning “Do you do any weight training” with yes/no responses.