You should find out your training heart rate zone for your correct training zone to know if you are training at the right pace.

Training Zones:

• Healthy Heart Zone (Warm up): 50 - 60% of maximum heart rate
• Fitness Zone (Fat Burning): 60 - 70% of maximum heart rate
• Aerobic Zone (Endurance Training): 70 - 80% of maximum heart rate
• Anaerobic Zone (Performance Training): 80 - 90% of maximum heart rate
• Red Line (Maximum Effort): 90 - 100% of maximum heart rate

To get an idea of which kind of training program is appropriate for you, you should check out the recommended target heart rate for your fitness level to avoid over-exertion and injury during your workout.