A Chinese grandfather has run a marathon in under three and a half hours – despite chain-smoking all the way. The 50-year-old, known as ‘Uncle Chen’, ran the race in Jiande, China, last week, only slowing down to light up again in recording what is thought to be his personal best time. Chen, who apparently only smokes when he runs, finished 574th – in 3:28:45 – out of nearly 1,500 runners. Camera Icon A Chinese grandfather has run a marathon in under three and a half hours – despite chain-smoking all the way. Credit: Weibo / Weibo Snaps of the…