Is this a good program?

[markopolo100]

Hi everyone, I am 26, 5-9, 165 pounds. I've lost 52 pounds since last June.

I would love some advice on how to improve my cardio efforts. Thanks so much.

I lift three days a week (with a 15-minute cardio warmup).
I do a 56-minute cardio program three other days a week.

My cardio workout was given to me by a personal trainer after he tested my heart rate threshold at 165.

All of my cardio is done on an elliptical machine. I monitor my heart rate at all times and vary resistance and speed by that.

Time, RPM, resistance
3 minutes, 70-75RPM, resistance 2, heart rate 120-140
4 minutes, 77-83RPM, resistance 4, heart rate 140-150
4 minutes, 77-85RPM, resistance 8, heart rate 150-165
2 minutes, 75-80RPM, resistance 4, heart rate 120-140
6 minutes, 77-85RPM, resistance 8, heart rate 150-165
2 minutes, 85-92RPM, resistance 11, heart rate 165-180
6 minutes, 77-85RPM, resistance 8, heart rate 150-165
2 minutes, 85-92RPM, resistance 11, heart rate 165-180
6 minutes, 77-85RPM, resistance 8, heart rate 150-165
2 minutes, 85-92RPM, resistance 11, heart rate 165-180
6 minutes, 77-85RPM, resistance 8, heart rate 150-165
2 minutes, 75-80RPM, resistance 4, heart rate 120-140
6 minutes, 77-85RPM, resistance 8, heart rate 150-165
5 minute cooldown

TOTAL: 56 minutes

In the past month, my performances haven't improved much. How do I take it to the next level. Any thoughts or suggestions?

Thanks so much for your help.
Marko