Country music icon Willie Nelson has been given double the reason to celebrate his birthday this week (begs28Apr14) after receiving a fifth-degree black belt in the Korean martial art of Gong Kwon Yu Sul. The veteran singer, who turns 81 on Wednesday (30Apr14), was presented with the accolade and a special scroll from his instructor, Grand Master Sam Um, during a ceremony in Austin, Texas on Monday night (28Apr14). Nelson, who is also an expert in the martial arts of kung fu and tae kwon do, did not show off his self-defence skills at the presentation, but admitted he had never imagined achieving such a high standard when he first started studying the martial art two decades ago. He said, "Honestly, I was surprised to be getting this degree. I don't know what else is out there. I never thought about anything beyond second-degree black belt." And he has credited his longterm training for helping him stay in tip-top shape: "I'm pretty healthy at 81. I think martial arts is one of the best exercises you can do. Mentally, spiritually, physically, everything. I'm sure that's helped." The black belt was Nelson's latest honour - he was inducted into the Austin City Limits Hall of Fame by actor Matthew McConaughey on Saturday (26Apr14) in recognition of his career achievements.