Watch Grand Valley State tackle a fartlek before the 2017 DII NCAA Cross Country Championships, where the men finished runner-up and the women placed sixth overall. THE WORKOUT: Men: 8 min. hard, 1 min easy, 7 min. hard, 1 min easy, 6 min. hard, 1 min easy, 5 min. hard (faster pace than before), 1 min easy, 4 min. hard, 1 min easy, 3 min. hard, 1 min easy, 2 min hard, 1 min easy, 1 min hard, 1 min easy. Women: The same as above, but working down from 7 minutes hard instead of 8. THE COOL-DOWN: 30-sec. strides