In Chapter 14 you’ll be able to visit the gym to start - and finish - the quest Wavering Heart, which is all well and good, but it’s only the tip of the iceberg when it comes to the subject of this trophy: the pull-ups minigame. To earn this trophy you’ll need to defeat Andrea, after which you can challenge the regulars - Ronnie, Jay and Jules.
To earn this trophy you’ll need to defeat Jules, the other contests with Andrea, Ronnie and Jay are just warmups. Fundamentally the pullups minigame is very similar to squats in that you’ll have to rhythmically press the [Triangle], [Circle], [Cross] and [Square] buttons, although this time the order in which you’ll have to press them is randomly determined at the start of each round. Each match spans two rounds - another innovation that differs pullups from squats - which really just gives them an opportunity to switch up the button sequence.
Otherwise, it’s largely the same; you’ll need to start out slow, rhythmically pressing the aforementioned randomly ordered buttons, picking up speed as your combo count increases. Once in a while you’ll have to mash one of the buttons (always the first button in the combo), and this is honestly the trickiest part of the minigame, as it can be easy to lose focus and press the flashing button on the screen out of order. As with squats you can take a moment to collect your bearings - useful before and after you have to mash a button to continue your combo and the timing is fairly generous.
Do yourself a favor and mute everything in the game save the sound effects to limit distractions. Jules will almost always fall off the bar near the beginning of round one (around 6-7 pullups in) and will regularly fall off near the end of the second round (when he hits his maximum of around 42-44 pullups). Don’t pay attention to Jules’ score, you can’t do anything to change that, and he almost always ends up around the same 42-44. Fretting about it will only distract you, and it’s largely your performance that will determine the outcome, not Jules’. If you fall off the bar at any point, you might as well just quit and try again, but if you end the first round with 18-24 pullups, you’re probably in a position to try to win in round two, whatever Jules’ score is. The final fifteen seconds are usually where your heart will be broken, as you’ll almost invariably have to mash the first button of your combo twice in that time, and the faster you’re moving, the easier it is to get tripped up.