I think the problem you have is that you don't know which 'you' is making the decisions. Let's call the 'tricking' you 'You' and the one you are tricking 'Body-You'. Then here is how the conversation goes:
You: "Time to get up and run."
Body-You: "Oh hell no. I'm tired. Plus we did a good job yesterday. And we have a lot to do today. Also, we don't want to over do it do we?"
You: (sighs) "Fine. Let's at least walk for 30 minutes."
Body-You (sighs): "Ugh. Fine."
10 minutes of walking pass.
Body-You: "This feels great! Let's run."
You: "Okay."
...
First notice that You said, "at least." You is not lying. If, at minute 30, Body-You is like "Ugh, still no," You can capitulate.
Second, notice that it is Body-You that makes the decision to turn it into a run. In your version, Body-You never gets what it wants. Both times You has to control the situation. The first time, to start the run, the second time, to enforce a more-or-less arbitrary contract for the sake of the contract, even though both parties want a new contract.
I feel the same thing Valakas is describing. Which of the "you"'s is remembering the next time, "yeah but 30 minutes that's not how it went last time"?
(also, I don't think body-you would say "we have a lot to do today"?)
Body-You will say anything to get what it wants, including “We don’t have time.” I’m calling it Body-You but, at least for me, it’s really a collection of parts of my mind that are against the action.
As for the “lying”, Body-You knows it is not a lie but doesn’t care. If You believes You is lying, Body-You is more than happy to use that as yet another excuse.
Personally I call these two people the "Planner" and the "Doer". Neither of them start out with bad intentions, but only one of them has to actually do things in the present moment, so resentment can definitely build up between the two.
You: "Time to get up and run."
Body-You: "Oh hell no. I'm tired. Plus we did a good job yesterday. And we have a lot to do today. Also, we don't want to over do it do we?"
You: (sighs) "Fine. Let's at least walk for 30 minutes."
Body-You (sighs): "Ugh. Fine."
10 minutes of walking pass.
Body-You: "This feels great! Let's run."
You: "Okay."
...
First notice that You said, "at least." You is not lying. If, at minute 30, Body-You is like "Ugh, still no," You can capitulate.
Second, notice that it is Body-You that makes the decision to turn it into a run. In your version, Body-You never gets what it wants. Both times You has to control the situation. The first time, to start the run, the second time, to enforce a more-or-less arbitrary contract for the sake of the contract, even though both parties want a new contract.