It only decays -3 if they haven't exercised at all. So if they visit Hanging Gardens, Gym or Parks, their fitness level should go up, not down. They must be visiting something else.

What are their interests? What else do you have in the Dome?

Diners are usually the culprits at reducing Fitness since Colonists will satisfy their need for Social there (while they eat) and forego visiting any of the other establishments.

A few Grocers on Hard Work are usually much better than Diners.

Thanks for all your amazing mods but I feel like you made this one too hard.

I found that only way to keep the fitness average in green is to have gym as the only social source in a dome. -3 decay is too much compared to the +s they get.

On my current colony I have a dome with fully staffed gym in hard work, min shift performance is 137. Have a hanging garden, plus couple of parks, and Martian diet breakthrough. Dome population is 147, none of the colonists are getting missing service penalty and I have minimal unprepared food penalties. Still I couldn’t find a way to keep the fitness average above 50.

That's great to hear, i just recall that back then i couldn't get more than 3 perks on a biorobot with gurus or morpheus, but if the fit perk is no longer counted towards that limit, and your other improved wonders mod now allows morpheus to give up to 7 perks, then the only thing i could think of that might be an issue are gurus and how many perks people can have before they can't receive any more from the gurus.

Glad that fit isn't counted towards this limit anymore, means that even if we still only could get up to 3 perks we now basically can get 4 now that fit is pretty much free if you do things right.

Thanks for making this mod btw, i felt like colonist stats were okay but not very in depth, so having another stat to manage makes things a bit more interesting.

Colonists can have as many positive and negative traits as they can possibly have.

It's just when generating their personality (which happens when they become adults) that they get a random number of traits between 1 and 3. With this mod enabledz, Fit won't be assigned as a random trait anymore, so it doesn't count.

You can't cure Unfit at the Sanatorium (unless you have another mod allowing it, but that would create a exploit, because the Fitness level would still be low, and the colonist would become Unfit the next day)

Oh and another question: If a colonist gets a fitness level below 30, and gets the unfit negative trait, can it be "cured" and replaced by a positive trait by the sanatorium?

IIRC atleast in 2018 colonists could only have 3 positive/negative traits and then have things like martianborn, founder, biorobot, and other special traits independent of the 3 basic ones.

If a colonist achieves a fitness level of 70 or above and gets the fit perk, does that take up one of the 3 basic slots, or is it treated like one of the special/unique traits that is independent of the 3 basic slots?

I used to train my biorobots with workaholic, enthusiast, and composed as base traits and wouldn't want to trade in one of them for the fit trait, but if you could have all 4 at the same time i'd love to use this mod.

The problem with Casinos is that they have 70 service comfort. That's way more than the Gym, so Colonists will prefer to visit the Casino for Social rather than the Gym. One trick that often works is to understaff the Casino to lower it's comfort, just below the Gym. Diners have a similar problem.

The default service slice (which btw should be updated to replace the Diner with an Ampitheater) works alright for the base game, but with this mod, Gyms/Hanging Gardens are needed.

Thanks, Tremualin! Amazingly detailed response, and much appreciated!
To start out the turn-around, I built a gym in a nearby dome and staffed it with fitness coaches -- that seems to be having an impact already. I didn't know Casinos were so bad for fitness! (My primary dome has one, so that definitely could have contributed to the problem.)
I also hadn't realised that diners had those issues: I think I read somewhere, before playing this (my first) game, that every dome should have a 'service slice' consisting of Diner / Infirmary / Grocer, so that's what I've been doing. Your comments make me seriously rethink that (probably wrong, or anyway far too generalising) advice!
Anyway, thanks again for the help, and of course for all the AMAZING mods. (literally just had my first domestic dust-up... exciting times on the Red Planet!)

Also, remember that colonists prefer to visit services with higher comfort. If you have a Diner and a Gym with Fintess Coaches; whichever has the most comfort will be used first. You can turn Heavy Workload on the Gym, but not the Diner, to keep the Gym more desirable.

Casinos are terrible for Fitness. Consider building them in connected Domes. Colonists will look in their own Domes for a service before looking somewhere else. This trick works for Diners as well.

In the late game, Hanging Gardens are great because they provide moderate amounts of Fitness for people looking for Relaxation.

Hope that helps.

Check for colonists eating unprepared food; that lowers their fitness levels quickly.

Some specializations, like botanists, have a hard time becoming fit, because they don't have the social interest.

Make sure they're visiting grocers and that those grocers have good performance so they can benefit from good nutrition. And that there's a gym with Fitness Coaches. Both bonuses stack, so they'll get many Fitness points.

Diners can be counterintuitive because people satisfy Social there instead of going to the gym. Try to use them only when necessary (Engineers).

Addendum: It's only my Martianborn youths who are 'Fit', plus one colonist who was 'Fit' to begin with. Everybody else is 'Unfit'...

Help! (lol) I love the notion of this mod, but I activated it in early game, and now 52 of my 60 colonists are 'Unfit'! Do you have any tips for me for turning this $#8t-show around? Thanks kindly!

Another great idea! Really like this addition to the game!