The aim of this session is to develop your threshold running — longer repetitions of 8, 6, 4, and 2 minutes. However, as a little surprise, the pace gradually gets faster going from just below to just above threshold pace. This further stresses your physiology and pushes up your threshold speed. Threshold is the point at which the powerhouse of the muscle cell (mitochondria) can no longer produce energy (ATP) aerobically. As such, threshold training is performed at a high intensity, somewhere around 7 or 8 out of 10 in terms of perceived intensity. Be sure to have your legs tip-top before getting stuck into this session! PS. It's also a great session to do off the bike.
For WHOOP users - This workout is ideally done on a Green Recovery day. These threshold intervals will challenge you and result in a higher strain score. If you aren’t well recovered, get some rest and come back to this workout on another day.