The 5 training zones based on lactate threshold

Why this matters

Zones become more useful when they are tied to LT1 and LT2 rather than only to max heart rate or FTP.

What to record

For every useful lactate analysis, intensity and lactate must be linked clearly. Record pace or watts, mmol/L value, heart rate if available and the stage duration.

• Pace or watts for each stage
• Lactate in mmol/L
• Optional heart rate and RPE
• Test conditions such as heat, altitude, sleep and nutrition

How to interpret it

Look at the curve, not only at one value. LT1, LT2, VLamax and zones become more reliable when the protocol is repeatable and the curve shape is plausible.

• Zone 2 should respect LT1
• Threshold work sits near LT2
• Heart rate can support control
• Update zones after meaningful fitness changes

Practical next step

Use the same protocol for future tests and compare trends instead of overinterpreting one isolated result.