One day, the duck-rabbit will publish a whole series of handbooks, and The Duck-Rabbit’s Guide to Running will be one of them.
There will also be The Duck-Rabbit’s Guide to Writing a Book, The Duck-Rabbit’s Guide to Parenting, and so on and so forth. The premise of each of these invaluable handbooks will be that in order to get anything done other than lolling around all day, you have to overcome an epic struggle between the short-term-pleasure focused, lazy part of you (that would be the duck) and the long-term-achievement focused, ambitious part of you (that would be the rabbit).
The duck-rabbit experiences this struggle more or less any time it strives to do anything that involves arising from the sofa upon which it currently reclines. According to anecdotal evidence, not everyone experiences this daily struggle: some blessed individuals decide they want to do something and then they simply do it. Quite extraordinary!
Obviously, these handbooks will be of little use to such individuals. But for persons who do experience this constant push-pull between short-term pleasure and long-term goals, the duck-rabbit’s series of (handy, pocket-sized) guides will prove indispensable. The key is using the rabbit to trick the duck. This isn’t all that hard, because the duck isn’t much of a thinker, let’s be honest. Still, it does involve a certain degree of subterfuge on the rabbit’s part. Consider the following dialogue as a case study. 
Rabbit: We’re going for a walk, just to clear the head, get some fresh air.
Duck: Sure, whatevs.
Rabbit: All right, so let’s get our gear on.
Duck: “Our gear”?
[Pause during which the rabbit patiently retrieves all of the various pieces of exercise clothing—the shorts, the sports bra, the running top, the visor, the running socks, the running shoes—plus all the other necessary accouterments—the sunblock, the headphones, etc.—and garbs (and in the case of sunblock, slathers) the duck-rabbit with said items.]
Duck: Bloody hell.
Rabbit: [testily] What?
Duck: I just don’t get why, if we’re just going for a walk to clear our head, we need all this brightly colored spandex.
Rabbit: Well, it’s a warm day.
Rabbit: This is special moisture-wicking fabric. We’ll be much more comfortable.
Duck: I dunno. It just looks like we’re trying really hard to be athletic or something. And we’re just going for a walk!
Rabbit: Look, let’s just go, we’re all spandexed and sunblocked now, we might as well go outside.
Duck: Oh, fine.
[They walk out into the bright sunshiny afternoon. It’s a lovely day with a cool breeze. They happily stroll along together singing along to Amy Winehouse on their iPhone.]
Rabbit: Ooh, this is a quite a bouncy song, don’t you think.
Duck: Not really. Actually, it’s a bit depressing, when you think about it.
[They walk for a few more minutes. Another song comes on.]
Rabbit: D’you fancy to running to this one?
Duck: Not really.
Rabbit: Let’s try, just for this one song.
Duck: Oh, fine.
[The duck-rabbit breaks into a modest trot for most but not the entirety of the song, which turns out to be quite a bit longer than it expected.]
Duck: [doubled-over with a stitch] Fuck, are you trying to kill me!
Rabbit: There, don’t you feel invigorated!
Duck: If by “invigorated,” you mean winded and clammy, then, yes.
[They walk for five more minutes.]
Rabbit: You know, it’s been over half an hour since we left the house.
Rabbit: Wouldn’t you like to get home soon and lie on the sofa?
Duck: [Perking up]: yeah, why, shall we Uber?
Rabbit: No, I was thinking we could run home.
Duck: Ha! No thanks.
Rabbit: Why not? Think about it. We already have our running clothing on. We have to get home anyway. It will be quicker if we run. And there’s some Britney Spears coming up on the playlist, it’s going to be awesome.
Duck: You are such a fucker.
Rabbit: [innocently] I don’t know what you’re talking about.
Duck: You tricked me!
Rabbit: You are so paranoid!
Duck: Your proposal that we “go for a walk” was a ruse to make me go running, which you knew I would never agree to otherwise.
Rabbit: Hey, I’m not making you do anything. I’m just proposing running as the quickest and most efficient way to get back to the sofa. [Coaxingly] You do want to get back to the sofa, don’t you?
Duck: Stop saying the word sofa. [Blocking its ears with its wings] rhubarb, rhubarb, rhubarb, I can’t hear anything you’re saying.
Rabbit: [Chanting] So-fa! So-fa! So-fa! So-fa!
Duck: [Unblocking its ears] Look, what I object to, less than the running—
Rabbit: So you don’t object to the running?
Duck: [Ignoring Rabbit]: What I object to, is the deception. You propose a lovely walk and then you ambush me halfway through with this [disgusted tone] running.
Rabbit: Not to be a pedant, but I’m not sure that, technically, one can ambush oneself.
Duck: Oh, but one can! Because one just did!
Rabbit: But how can you possibly say you didn’t see this coming? We ran 26. 2 miles because I told you we were just going with Marissa to lend moral support while she signed up to run a marathon.
Duck: I’m tired of arguing. I just want this outdoors portion of the day to be over as soon as possible, and the quickest way to make that happen is to run home as fast as we can.
Rabbit: You said it not me.
Duck: [Starts running, cursing under breath the whole time] You are such a cunt. And I am such a tool. [Picks up pace so as to bounce along in time to Britney.]
Rabbit: [Whispering to itself] Well played, Rabbit. Well played.
 I was originally going to write this in the first person; however, I watched Zootopia last night and was so charmed by the banter between the two main characters—bunny and fox—that I decided to revive the duck-rabbit dialogue.