I went for a swim for the 1st time in 10 years this afternoon. Now, since I was 14 (the last time before today that I swam) I have developed a penchant for beer and pizza, which has had a detrimental effect on my stamina. However, back them I could happily dive into a pool at 10 am and act like a fish on heat until dusk. So why in the name of god did I give up today after 20 lengths and half an hour?????? 4 hours later and I'm still knackered.