A 92-year-old Chinese veteran, Zhang Zhenqing, stunned the internet recently by showing off his splendid muscles and flexibility with moves on the horizontal bar as well as pull-ups and the splits, the results of decades of strict self-discipline and painstaking training. After retiring, Zhang found that years of hard work had left him with multiple chronic conditions, including gastritis, coronary heart disease and cataracts. He swears that the best way to shake off these troubles is to stay as