I ran this workout at sea level 8 weeks before my marathon last December and I ran a 2:42. I was running 50-65 miles a week.
6 x 1000m with 400 m jog. The jog took approx 130 seconds, so it was more than 2 minutes rest.
3:50, 3:56, 3:55, 3:52, 3:43, 3:47
I went to Mammoth Lakes around 7,800 ft over the sea level and ran a similar workout I'm still 14 weeks from my next marathon. I'm running now between 80-90 miles a week.
7 x 1000m with 60 seconds static rest.
3:47, 3:43, 3:42, 3:47, 3:44, 3:47, 3:46
Taking in account I still have 14 weeks till my race what would be a realistic goal for me?