Heart rate training zones divide the exercise intensity spectrum into bands, each targeting specific physiological adaptations. The 5-zone system (most common): Z1 recovery (50-60% max HR), Z2 aerobic base (60-70%), Z3 aerobic (70-80%), Z4 threshold (80-90%), Z5 VO2 max (90-100%). 80% of training should be in Z1-Z2 (the 80/20 principle). Zone 2 builds the aerobic base and fat-burning capacity. Zone 4 directly raises the lactate threshold. Zone 5 develops maximal aerobic capacity. Heart rate zones can also be calculated from LTHR for greater individual accuracy.
Key points
- 5 zones from recovery to maximal
- Zone 2 (60-70% MHR) for aerobic base
- Zone 4 for threshold development
- 80/20 principle: 80% easy, 20% hard