I used to run reg­u­larly but stopped when my left knee began to hurt. When I restric­ted my gym ses­sions to the cross-​trainer I was pain free, but 10 minutes after going back on the tread­mill, my knee star­ted hurt­ing again. It then made a “click­ing” sound as I walked home. What have I done and how can I make it bet­ter?...

I run four or five times a week (usu­ally for about 40 minutes). A month ago I developed pains in my right shin dur­ing a long run, which las­ted for a few days. Since then, the pain returns whenever I try to run. Could I have shin splints? If so, how long will it take to heal and how will I main­tain my fit­ness levels in the mean­time?...

After a few drinks on a night out, I find the best way to get rid of a hangover is to do a strenu­ous workout because it makes me feel bet­ter. However, my wife says this is a bad idea because I will be dehyd­rated. Is she right?...