I did this workout at the track Saturday:
You'll need two markers. I just used two socks. Set your watch or Gymboss timer for 30 seconds. On Go: sprint around the track. When 30 seconds hit drop the marker (sock). Now walk back to the start. Set the 30 seconds again. Go again and try to beat the previous mark. If you do, drop the other marker. If you don't the first marker stays and it means you ran slower. Do eight sprints. I beat the marker six out of eight. Distance doesn't matter. Just try to beat the marker. I thought of using small dumbbells for this too. I guess it's sort of Tabata-like but not exactly. I'll try this twice a week. Any suggestions for changes/improvements?