I have a 57 rhr. i workout 3-4 times per week and struggle to get my heart rate into an aerobic zone. i try to burn 600 calories per workout but per heart rate monitor it takes 1:30 hours. with bradycardia is heart rate indicative of calorie burn?

Doing good: Please do not obsess about heart rate and calories burnt. If you maintain a healthy weight and exercise 150 minutes/week you are doing great. Over exercising may not be a good idea. For good health - Have a diet rich in fresh vegetables, fruits, whole grains, low fat milk and milk products, nuts, beans, legumes, lentils and small amounts of lean meats. Avoid saturated fats. Exercise at least 150 minutes/week and increase the intensity of exercise gradually. Do not use tobacco, alcohol, weed or street drugs in any form. Practice safe sex.