I don’t think that matters. If the purpose of the reward was to bribe yourself to do it (i.e. consciously thinking “I’ll go to the gym because that way I’ll get to read some fiction afterwards”), then yes, you’d have to find some way of withholding the fiction until you’ve been to the gym. But I think the behaviourist sense of “reward” is different; it’s to reinforce the behaviour by creating a pleasant feeling which the brain then associates with the prior action.
To illustrate, I once tried to use this method to improve my punctuality (I wish I could say it worked, but I didn’t keep it up for long enough). I had a bag of sweets and if I got set up to join a virtual meeting 5 minutes before the start I would eat one. My friend said “If that was me I wouldn’t be able to stop myself from eating them at other times.” I said “Well if I do I’ll buy some more! It’s my punctuality I’m trying to improve, not my waistline”.
I don’t think that matters. If the purpose of the reward was to bribe yourself to do it (i.e. consciously thinking “I’ll go to the gym because that way I’ll get to read some fiction afterwards”), then yes, you’d have to find some way of withholding the fiction until you’ve been to the gym. But I think the behaviourist sense of “reward” is different; it’s to reinforce the behaviour by creating a pleasant feeling which the brain then associates with the prior action.
To illustrate, I once tried to use this method to improve my punctuality (I wish I could say it worked, but I didn’t keep it up for long enough). I had a bag of sweets and if I got set up to join a virtual meeting 5 minutes before the start I would eat one. My friend said “If that was me I wouldn’t be able to stop myself from eating them at other times.” I said “Well if I do I’ll buy some more! It’s my punctuality I’m trying to improve, not my waistline”.