I had the same experience before. After running for 5 minutes, my heartbeat rate had already over the max. heartbeat rate. After continuous practice, my heartbeat is back to normal after 6 months. My normal heartbeat is slowed down from 70/min to 55-60/min. Running is very good to healthy as long as you do not have knee problem.
小弟十之欣賞樓上師兄/姐嘅running philiosophy! 點到即止, 這樣才可以大大減小受傷的機會. Always remember 這金言"LISTEN TO YOUR BODY AND RESPECT THE DISTANCE". 小弟在這邊world認識很多新入行嘅beginner runner. 佢地一日跑到黑, 跑呀跑, 練呀練, 為咗要達到goal time! 傷都照去, 究竟為乜呢? 走火入魔? 亦更不明白練到喊都要continue練落去.