Find your training zones using the Karvonen formula
The simple formula for maximum heart rate is 220 minus your age. A 35-year-old has a maximum heart rate of approximately 185 beats per minute. The fat burning zone is 50-70% of max heart rate (93-130 bpm for a 35-year-old). The cardio zone is 70-85% (130-157 bpm). Resting heart rate below 60 bpm indicates strong cardiovascular fitness.
Heart rate zones divide exercise intensity into ranges based on percentage of maximum heart rate. Each zone produces different physiological benefits — lower zones burn a higher percentage of fat while higher zones build cardiovascular endurance and aerobic capacity. Training in the right zone for your goal makes exercise significantly more effective.