When I am feeling OK, I try to go for a short walk (around the block or similar) but at present (2nd chemo was on Monday with mild Low hemoglobing before I began), I am having REALLY BAD fatigue, I am fighting to get out of bed and go to the Loo, so going for a walk is just WAY beyond me, So I am not sweating it, when I start to feel a bit better, I will go for a walk, until then I will rest and relax and sleep/ nap until I am up to doing more.
I don;t even have the energy to want to eat (although I am forcing myself), I have decided that if I am still this bad tomorrow I will call my chemo nurses/ breast nurse or oncologist and see what I can do to help it (maybe I need iron suppliments or something to help the low hemoglobin as this HAS to be adding to the post chemo fatigue I get anyway), but until then, rest, rest, rest and I REFUSE to feel guilty about it. IF this is what my body wants, the is what my body will get.
Good Luck to you and to finding a balance that is right for YOU. It is so HARD as like you said the information is conflicting and we are ALL so different, we all react differently to our treatments (our chemo meds are different, our bodies are different, our cancers care different, our genetics are different, our pre cancer fitness levels are different and so on and so forth), so I can't see how there can be a one size fits all answer.
I say, do what seems right for you - if you go for a short walk - to your mailbox and that is fine, maybe try a little farther. If you get to the end of the street (and remember you have to walk the same distance to get back) and you feel fine, maybe try to go a bit further.
I do recommend you carry your mobile phone with you though, so if it is too much you can call someone to pick you up in a car (even if it is form the end of the street or from 2 doors down), My hubby demands that i keep a phone with my if he is not in seeing/ hearing distance from me - JUST IN CASE, so I can call him, if I need assistance (we have walkie talkies for at home <LOL> as he is working in the garage a lot building our 4x4 motorhome.
Good luck with find a balance for yourself (I KNOW it is a hard one).