These cut-offs mark the points where your body switches how it makes energy. Pin them down and every session lands in the range you actually meant to train.

Lower threshold is where the base effort band ends and the tempo band begins. It normally lands near 58–78% of your ceiling, or roughly a 3 to 4 on a ten-point effort scale. It also tends to sit about 20 to 40 beats under your upper threshold, though the gap narrows as you get fitter.

Upper threshold marks the handoff from the tempo band into the redline band. It tends to sit near 80–92% of your ceiling, or about a 7 on that same scale — hard, but holdable. Functional threshold pulse, lactate turn point and upper threshold are, for training purposes, three names for the same number.