My coach gave me this session to tune me up for the mara:
6 x 300 @ 50sec w/ 2:00 rec - slight tail wind @ 2000m altitude on gravel track in Oz
Kicked home with a 49 point last rep
program usually is 40 mile week with 15 mile long run and 2 sessions - as you can see I've got killer speed, hoping to run under 2:40 soon