Hi it’s a slow build up but I was told you had to remember chemo was a three week cycle and you didn’t feel like running a marathon at the end of the three weeks 
We’re all different and our treatment plans differ so much . I had MX first followed by chemo and was told about three month for chemo to be out of system hence the need to wait for optician appointment as eyes could change .
I did feel better as weeks moved on but my age 70 at the time won5 have helped . Also I was on Herceptin so still three weekly cycle . Then lockdown arrived so difficult to build fitness.
My advice is be patient listen to body rest when needed to but start to build fitness levels slowly but surely . Then one day you’ll realise your back !!
