W5/D4: 5k specific fartlek

-15-20 minute warmup plus drills and strides. -Run 5 minutes hard, 5 minutes easy, 4 minutes hard, 4 minutes easy, 3 minutes hard, 3 minutes easy, 2 minutes hard, 2 minutes easy, 1 minute hard (Run the hard segments at 5k goal pace) -15-20 minute easy cool down