Backgrid USA Adam Levine is getting in an outdoor workout. The 47-year-old musician, who is the lead singer of Maroon 5, carried a 45lb kettlebell as he went for an afternoon hike on Saturday (June 13) in Los Angeles. For his workout, Adam showed off his massive tattoo collection while wearing a white tank shirt and black running shorts. Back in April, Adam won the most recent season of The Voice and he also just made a rare red carpet appearanc…