opps, just wondering

[go4gold]

I have been doing my cardio for about 45 min a day, my problem is that i have been keeping my heart rate at like 160, their has been times where i have gotten it to almost 190 a few times. I run the walk, then run again, my rate never dropped below 145. I just did some calculations and found my target rate to be about 125-145. u guys don't think i was burning muscle. I was wondering why my cardio was so **** hard.

[Hypertrophy]

Steady state activity is better than run/walk/run.