• Zone 1 (50-60% HRM) (6+ hours) 50-60% effort ・ easy breath
• Zone 2 (60-70% HRM) (1-3 hours) 60-70% effort ・ talking full sentences
• Zone 3 (70-80% HRM) (40-90 min) 70-80% effort ・ talking short phrases
• Zone 4 (80-90% HRM) (6-40 min) 80-90% effort ・ barely talking
• Zone 5 (90-100% HRM) (< 5 min) 90-100% effort ・ maximum effort

80% of training should be in zone 1-2, 20% in zone 3-5; e.g. z2 z2 Z3 z2 z2 Z3

My maximum heart rate is 193. Therefore: Zone 2 143-155 bpm; Zone 3 156-169 bpm

C25k