Work out
Source Character Operations Manual pg. 155
Whether through aerobic exercise, pumping iron, sparring, or otherwise putting yourself through the paces, you push your body to improve its performance.
Results: On a success, once per day for the following week, you can reroll either a failed Acrobatics check to balance, escape, fly, or tumble, or a failed Athletics check to climb, jump, or swim, depending on the focus of your workout. On a failure, you can reroll a corresponding check only once during that week.
Multiday: Decide whether you’re working on your agility (to improve your Acrobatics) or sheer physical power (to improve your Athletics). You spend 7 days carefully alternating intense training and mindful rest. If this activity is interrupted, you can resume it within 2 days to keep any progress made toward the 7-day total. At the end of 7 days, attempt a Fortitude saving throw with a DC equal to 10 + half your character level—you gain a +2 circumstance bonus to this save if you have access to an exercise-focused recreation suite (such as a gym or sparring arena) or similar facility.
While the ship did not have a dedicated gym it did have some work out equipment stored in bins in the cargo hold to be used. Mostly just some yoga mats, dumbbells, some weights and bars to lift, exercise balls, jump ropes, and some resistance bands to help keep the crew fit. It certainly would not fully replace an actual gym but it was the best they could do in the limited space on the ship.