On the latest episode of MBC Every1's Idol Army Season 5, they revealed MBLAQ's Lee Joon working hard on his chocolate abs. The episode showed a clip in which MBLAQ visited Japan for their concert. When the concert was over, it was past 12:00AM. Due to the late time, Lee Joon commented, "I don't think I can go to the health club so I brought it along with me," and then revealed a set of exercising equipements he brought along the trip. During his workout later that evening, he even surprised G.O, who was filming him, by taking off his clothes. Through the clip, Lee Joon also revealed an effective way to do sit-ups which help burn your belly weight. Stay tuned to this episode on the 17th to find out!