I added fartleks to the Cabela loop for my workout today. It was a total of 3.09 miles with 7-8 fartleks, I lost count. I tried to do a pyramid of sorts the first was 30 seconds then 40, then 50, then 60, then 50, 30, 40. I meant to do two 60 second fartleks but can't remember. It took 44:14 total.