One run a week is an hour long. I do it as soon as I get up because of the impossibly hot temperatures. It should be a 10k run but I only manage around 7.5 . Not great I know, but I am of a certain age and boy, it ain't half hot here even at the crack of dawn. Anyway, what I don't get it how my first 30 minutes is at a good tempo -- ok, not a full 5k but almost. Then I seem to slow down for about 15 minutes followed by Usain Bolt style energy at the end. Now, is it my old battered body or my head? Am I naturally inconsistent or am I really tired? I did try jelly babies -- orange and purple if you must know -- nice and dentist will kill me, but whether they actually energized me I'm not too sure.