Described as a "Soulful Journey", and is sure to take your mind and body to the next level, Volume 4 REALLY turns up the heat!

• Challenge 1: level 3 sprint for 2 minutes, 30 second recovery, level 3 hill for 2 minutes, 30 second recovery, level 3 sprint 2 minutes.

• Challenge 2: level 3 hill for 1 minute, level 4 hill for 1 minute, 30 seconds rest, then do it all again (2 more times).

• Challenge 3 (optional): level 3 hill for 3 minutes, 1 minute recovery, level 4 sprint for 45 seconds, 1 minute recovery, level 3 hill for 2 minutes, 2 minute recovery, finish with a level 4 sprint for 1 minute.