First of all, congratulations on your continued healing.
I'm in a similar spot to you -different cancer, and a few months further along in the healing process. But basically, similar.
Here's how it's playing out FOR ME. When I started to exercise again, I quite literally couldn't make it to the corner without gasping for air and my heart racing. And I had been quite physically fit before. Well, to be honest, I had been quite physically fit in the past. JUST before my diagnosis, I hadn't beem working out all that much. But anyway....
I did what I could. I made the most pathetic training plans you ever saw. And I showed them to NO ONE, because they were so embarassing. I had to work my way up to walking for 1/2 hour. And then I added one minute of running in that half hour. And some days I broke it up into two 30-second sessions. And I had to stay at that level for probably two weeks or more before I could add another 30 seconds of running. It was dismal.
But then -all of a sudden- I could do more. The slow running progress just bugged me, so I ran for 30 minutes. Well, jogged.... but you know what I mean. I picked my feet up, for heaven's sakes! I could swim more. I could go biking with my husband again. When I started to WANT to do those things, as opposed to making myself do them or else my entire body would probably shrivel up in atrophy, then I came to this site. And I'm not even exaggerating. One day, it was just different. I was back in the land of the living.
I'm still bringing up the rear in probably every indicator of triathlon goddess-ness. I'm okay with that. I give people the comfort of knowing that there's SOMEONE they can beat
And I know how far I've come.
To answer your specific question... I would let my heart rate get up to 180, but not higher than that. And 180 was probably pushing it at the time. My resting pulse was something like 90. It was crazy. I just gave blood a few weeks ago -my cancer history doesn't preclude that. ANd I got the "athlete question". My pulse rate was so LOW that they almost disqualified me from donating, but they'll let athletes go a little lower. I was thrilled!
Feel free to send me a private message if you want to talk more. And of course, your experience is going to be different from mine and you should do what your doctors tell you.... blah, blah, blah.....
Andrea