Describing life as a young man living in the closet in San Juan, Puerto Rico, Martin talks about years he spent questioning his sexuality, and believing he was wrong for being homosexual.
"I was very angry, very rebellious. I used to look at gay men and think, I'm not like that, I don't want to be like that, that's not me. I was ashamed," Martin told the magazine. "When you're told you're wrong by everyone, from society, from your faith -- my self-esteem was crushed. I took my anger out on those around me."
"I look back now and realize I would bully people who I knew were gay. I internalized homophobia," he revealed. "To realize that was confronting to me. I wanted to get away from that."
The "Livin' La Vida Loca" singer and mentor on Australia's "The Voice" officially came out as gay in 2010. Prior to that, Martin said, it really bothered him when people "pressured" him to come out, saying even at that late stage he was questioning his sexuality.
"If I had spent a quarter of the time that I spent manipulating my sexuality in front of a piano instead, I would be the most gifted piano player of my lifetime," said the former member of Puerto Rican boy band Menudo.
But ultimately he became comfortable with his identity. Since that time, Martin, 41, has fought for LGBT rights, and has received GLAAD's Vito Russo Award for his efforts to promote equality.
"What people were expecting from me was not who I was, and I forced myself to believe that what they wanted could be my truth, my reality, and I went after it hardcore."