Only those who will risk going too far can possibly find out how far one can go.
-T. S. Elliot

We all don’t all have a track nearby to workout at. Here’s a speed workout that can be done on both road, trails, and treadmill.
Fartlek
Warm-up:

10 minute jog

Main Set:

2 min hard run
1 min jog
4 min hard run
2 min jog
6 min hard run
3 min jog
4 min hard run
2 min jog
2 min hardrun
1 min jog

‘hard’ = above lactate threshold/race pace/NOT conversation pace

Cool-down:

Stretch