Bono, 44, was dressed in shorts and a T-shirt that showed off his recent weight loss and his muscles, E! Online reported.
The son of Cher and the late Sonny Bono decided to lose weight when he tipped the scales at about 250 pounds. In May he told People he had dropped 65 pounds and had at least 15 more to go.
"Physically, my body feels just so much better," he said. "I'm in a lot less discomfort when I exercise and am doing physical stuff. All of my numbers are all normal now, which is great -- my blood pressure, my cholesterol. I just have a lot more confidence, and that feels really cool. I really like what I see in the mirror."
Bono, named Chastity Bono at birth 44 years ago, transitioned from female to male in 2008 and 2009.
Swim Week Miami Beach 2014 [PHOTOS]