Simple yet hard day. Start with a 24 step lungewalk on either an uphill or flat surface and then accelerate a run from 0-100 meters. Walk back and take an extra 50 meters and stretch in between while taking 90 seconds rest. . Repeat this a total of 4 times and each run should be faster. This should be hard especially if it is warm where you choose to train. For runners do the runs at 400 meters with 50 step lungewalks. After run an all out mile. For novices take 3 minutes and run an all out 400 meters for time.