fartlek on the trail 9/7

Since the track was being used for a football game last night, we went to the trail and did a fartlek workout. I ran the 10 mile loop with a 2 mile warm up and then 20 X 1 min on / 1 min off followed by a 2 mile cool down. The workout got progressively harder after about 12 repeats of this cycle. I was finished with the last repeat at the rock, so did a cool down back to Rtex.
The best thing? no ankle pain. Felt good but I wished we could have done those 400's. I was looking forward to that. Maybe in a few weeks.