Something a little different...
Runner's World suggests running a 'pyramid' for improving speed. Thought I'd give it a whirl as I'm a bit bored with the idea of a straight 30 minute run. You run for one minute hard, then rest for 30 seconds, two minutes hard, rest for one minute, three minutes hard, rest for 90 seconds, and so on: 1-2-3-4-5-4-3-2-1.
It just happens to be the hottest day of the year. I'm also running on grass for the first time which is tiring in itself.
Anyway, I pretty much do it thought the longer runs are gentle jogs rather than fast. And I finish up with so much sweat in my eyes I can bearly see. I knew there was a good reason for wearing a cap...