Your lactate threshold is the wattage you can hold for roughly an hour before your blood lactate starts climbing sharply. It is the single most useful number in endurance training, because the intensity zones that train it sit just below and just above it. If you know your threshold, you can structure a class around four blocks that each ask a specific question of your aerobic system.
In Cycle Threshold we run four blocks. The first is a warm-up at zone two, which is twenty to thirty watts below your threshold. The second and third blocks sit at threshold, with three-minute efforts and ninety-second recoveries. The fourth block is a Vo2 effort, which is thirty to fifty watts above threshold, with one-minute efforts and one-minute recoveries. The class finishes with a long cool-down because the fourth block leaves most riders glycolytically empty.
The reason the screen shows your watts in this class is not motivational. It is because the prescribed zones only work if you actually ride in them. A common pattern we see in self-coached riders is that they ride the threshold blocks five to ten watts too high, blow up in the third effort, and then ride the Vo2 block at threshold rather than above it. The class is designed the other way around — hold the threshold blocks steady, then go above.
If you do not know your threshold, we run a twenty-minute field test on the first Saturday of every month at Old Oak. It is a twenty-minute maximal effort and the average wattage is a good estimate of your functional threshold power. From there we can set your zones for the class. The test is open to non-members; book at reception.
One last thing. Threshold training is boring by design. The blocks do not change much from week to week because the stimulus does not need to change. If a cycling class advertises itself as constantly varied, it is probably not threshold training. That is fine, but it is a different class. Cycle Rhythm is the room for that.