Hey Guys, Wondering if any of you could give me some perspective... I am 36 years old, 6'3, 240 lbs, 12% body fat (roughly) and I have been training for several years. I tend to have good strength and stamina during general conditioning training. However, when I do Bas Rutten Thai Boxing (full power) on the heavy bag (10-2 min rounds) it is hard to make it through all ten rounds. I'm dragging my A$% by round 6-8. Do any of you have a hard time with the Rutten workouts on the heavy bag or is it my conditioning. Thanks!