Aerobic Threshold Calculator

The aerobic threshold (AeT) is the exercise intensity at which lactate begins to accumulate in the blood above resting levels. Below the AeT, the body can clear lactate as fast as it is produced and can sustain exercise almost indefinitely. It corresponds to approximately 65 to 70% of maximum heart rate in most adults.

The Maffetone Method uses the formula: Maximum Aerobic Function (MAF) heart rate = 180 minus age, with adjustments: subtract 10 if recovering from major illness or medication; subtract 5 if training inconsistently; add 5 if training consistently for 2+ years without injury. This gives the upper heart rate for purely aerobic training.

The aerobic threshold (AeT) is the lower intensity threshold where lactate begins accumulating. The anaerobic threshold (AnT, also called lactate threshold 2 or ventilatory threshold 2) is the higher intensity where lactate accumulation rate exceeds clearance. The zone between AeT and AnT is optimal for sustained aerobic development.

Training primarily at or below the aerobic threshold (polarised or 80/20 training) has strong research support for endurance athletes. Easy aerobic training builds mitochondrial density, fat oxidation capacity, and cardiac efficiency without the accumulated fatigue from high-intensity work. Most elite endurance athletes do 70 to 80% of volume at or below AeT.

The most accurate methods require laboratory testing: blood lactate testing identifies AeT as the intensity where blood lactate first rises above 1.0 to 2.0 mmol/L above baseline. The talk test is a simple field test: AeT is roughly the highest intensity at which you can speak in complete sentences without breathlessness.