Weight loss is basically about calories burned versus calories consumed, not about what your heart rate is during exercise.
That said, when starting an exercise program, it's probably best to start out gently and gradually increase the intensity over several weeks. Your maximum heart rate can roughly estimated at 220 minus your age, or about 170 in your case. You should start out exercising at 60-65% (100-110 bpm), gradually lifting it to 75-80% (130-135 bpm).
The reasonable man adapts himself to the world; the unreasonable one persists in trying to adapt the world to himself. Therefore all progress depends on the unreasonable man.
| current weight: 178.0