Over time my bruising became less & less. It's important to use dit da jow & rub out those knots/bruise spots immediately after banging arms. These areas will be tender & you might need a partner to press firmly enough to break up the stagnation. Think of a happy place. Interestingly, a radiologist at work emphatically aruges against any kind of bone conditioning. Yet with decades of arm/hand conditioning behind them, my Sifu & Sigung don't suffer from any kind of degenerative bone disorder, nerve damage or arthritis.