By taking part in strenuous exercises while heavy bags are attached to their feet, the students become as light as a feather once the bags are removed.
練輕功的時候，腳上綁著鐵砂袋，身上穿著鐵衣，天天走豎板、跳砂坑，練重躍的功夫和抓勁。修練期間，不能洗澡，鐵砂袋也必須長年累月綁在腿上，不能卸下。如此三、四年下來，便身輕如燕，能飛簷走壁了。至於用內力療傷，雲樵先生自己就曾經歷過。