BEAST member KiKwang along with 2AM members Changmin and Jinwoon put on a special performance for the audience on the Chuseok Special of 'Fantasy Star Couples Challenge Cup'. The trio was also joined by Korean basketball star ??? (Woo Ji Won). All four men are known for their excellent physiques and body condition, so they all took center stage and did various exercises. Sounds simple, right? Well, to make things interesting they also had to sing 2AM's hit song 'Can't Let You Go Even If I Die'... while exercising! As a bonus they also performed BEAST's hit track 'Shock' shortly thereafter. Check out the hilarious performance below.