Hi Whymewhynow, 

I've had 7 rounds of chemotherapy among other treatments and you have to give your body a long time to recover. Chemo affects your whole body and having had all the main cancer treatments, I'd say it's by far the worst in how long it affects you. By all means keep as active as you can but don't push your poor body too hard before it has recovered.  My nails still break constantly 15 months after chemo and my hair isn't growing at its normal rate and still has chemo curls. I use these signs as a measure that the rest of my body will still be recovering too. Energy levels better than they were but not what they used to be. 

My hospital sent me After the Treatment finishes - Then What? by Dr Peter Harvey. You can find it online if you want to read it and it explains that recovery happens in 3 stages.

One day you'll get your miles up but try not to be impatient for this to happen. Good luck!