A no-nonsense stamina management mod, meaning that it doesn't meddle with anything and everything, only stamina- and/or weight-related events.

A MCM menu allows to configure the options.

Stamina drain when running or swimming fast, the amount depends on the InventoryWeight/CarryWeight ratio.
Moving with 100 kilos of loot doesn't impact on superdovahkiins with 1500 carrying capacity as it does on weaklings with 150.
The effect checks the actual movement speed [default = greater than 125] because 'running' and 'swimming' are unreliable conditions, and it's tuned for the vanilla movement settings.
If you have modded movement speed settings, a slider allows to tweak the threshold [100<->200].
0-Disabled, 1-Extra-Low, 2-Low, 3-Medium, 4-High
Default: Low

The stamina regeneration rate is reduced by the inventory weight, it takes more time to regain your breath when you're carrying around heavy bags, sacks, backpacks, and whatnots.
Restoration spells and potions suddenly become more useful than they used to be.
It depends on the InventoryWeight/CarryWeight ratio like the stamina drain and this too accommodates low- and high-level PCs.
0-Disabled, 1-Low, 2-High
Default: Low

Your maximum stamina is reduced while hurt and bleeding, you obviously feel weaker.
This is better explained with an example:
if your base stamina is 100 - 200 and you're at 50% health, you temporarily lose 56 points;
if your base stamina is 201 - 300 and you're at 50% health, you temporarily lose 110 points;
if your base stamina is 301 - 400 and you're at 50% health, you temporarily lose 166 points;
if your base stamina is above 400 and you're at 50% health, you temporarily lose 220 points [I didn't go higher because this would never reach an end. Where to stop? 500, 600, 1000, 2000 stamina? I just assume that above 400 you're so fit that, while being half dead is severely debilitating for a pipsqueak, it's just an annoyance for you].
Steps are at 25%, 50%, 75% health. I guess that a 0% health step would be a little... erm... redundant.
0-Disabled, 1-Low, 2-High
Default: Low

You sneak badly with all the clanking heavy stuff you carry around, the sneak value is progressively reduced by your inventory weight [It can even become negative, not sure whether this has an actual effect or it's like having the basic value of 15].
This is easily explained, the aforementioned bags, sacks, backpacks, and whatnots make you more detectable.
0-Disabled, 1-Low, 2-High
Default: Low

At zero stamina you feel really tired and can't run or fast-swim anymore, not much to explain here, I guess.
Stop, walk, drink a potion, cast a spell, swim slowly, or float in the water to recover.
Disabled or enabled
Default: enabled


To safely uninstall: disable all options -- wait for stamina and health to be back to normal if depleted -- save -- uninstall.
To safely update: disable all options -- wait for stamina and health to be back to normal if depleted -- save -- uninstall old version -- reload -- save -- install new version.

Disclaimer
This has been inspired by "Cardio SE - More Realistic Fatigue", I used it for a while but then I felt I needed something different.
I discarded all the disliked stuff and redeveloped the good ideas to suit my taste, mostly to have the effects take into account the actual stats and abilities of the player instead of being one-size-fits-all.
The mod is made from scratch and doesn't take anything from Cardio (apart from the already mentioned good ideas, of course).