I had thought at one point about letting players have a trait or feat that let them use their Strength as their Endurance base, rather than Vitality, but after i saw GURPS does that by default, i'm thinking of making the change permanent rather than optional.

Pros: This further rewards putting points on Str, my game's Damage base, as they will also become healthier as they become more powerful in melee. Characters not designed to deal lots of melee damage really have no business being in melee, and those characters designed to be meat shields will have ample ability to deal damage with the rest.

It also allows me to make things like Prana/Magic Points divided from Endurance/Hit Points by keeping the MP with Vitality (If i understand Prana correctly, the two are somewhat correlated).

Cons: I'm afraid of putting too much emphasis on any one Attribute, i want the duties pretty evenly spread out if possible so various character concepts may be devised and created and played accurately without having a super stat that everyone would be a fool not to put points on.

What other Base Health methods are out there?

I know D&D has HP based on class/dice roll, sometimes with Con added depending on the edition (or was that always there?)

Gurps uses ST at a 1:1 ratio for HP.

Many CRPGs, JRPGs, and MMORPGs seem to have their HP totals an arbitrary quantity based on the predefined notion of the game's balance.

In my rules' current rendition, Endurance has a base of 30 starting points, and the relevant attribute is added to that maximum (either Vitality or Strength, depending on which way i go with that).

Damage is dealt (for simplicity we'll assume Melee) based on weapon dice rolls plus Strength.

There is a level cap for each stat set at 14. No stat may be raised above that level, so the most Endurance a character may have without outside influence is 44 End. (Armor will grant additional points to Endurance, but i plan on keeping that low still.) I need to make sure Weapons don't do too much damage, especially not too early.

I'm making the game without the typical level progression, so stats will either remain static, or progress one point at a time through training. (no sudden and colossal jump in power levels. no going over 9000.)

There are a number of considerations that can recommend lumping together muscle mass, total mass, fortitude and (roughly) height. This is more so if your game focuses on generally big, strong, tough figures.

Realistically, the factors have a complex relationship. Most of the time, rules sets use approaches that make for (or at least allow for) pretty strange combinations.

TFT (simpler precursor to GURPS) had just ST, DX and IQ. Outside of combat, ST was not so valuable as the others, and I think that's pretty generally true in most games. Giving it more value in the limited domain in which it's frequently significant can help with game balance.

Thanks for the response!

Yeah, that's one thing i actually like about Strength in 2E AD&D, if it's high enough you can bend bars and break down doors. Donno if that's a thing in later editions, but I'm kinda doing that with mine. Strength determines your character's ability to lift/push/pull heavy objects, wield certain weapons, use physical intimidation, etc.

I figured muscled people might have more toughness than squishy people  

They don't have to be bulky though, some people have lean muscle, or "supernatural" strength beyond appearances.

I still have a Vitality stat, which used to be the base for Endurance, but i've pretty much concluded that one's constitution with illness is not the same as one's toughness, which is how i'm treating Hit Points in my game. Not as physical wounds and bloody gashes, but as bumps/scrapes/bruises. Death by a thousand cuts in other words. No single cut can bleed you to death, but all of them together will just put you into shock and you shut down. Without medical attention you will die.

My plan now is to let Vitality focus on being the poison/disease resistance, and possibly one's physical appearance. (certain aspects of physical beauty are usually equated with physical health, clear skin, healthy hair and nails, shiny teeth, sparkling eyes, etc.)

I had a list of a few different ways of determining hit points here:
http://www.therpgsite.com/showpost.php?p=496987#post496987

STR or CON- based HPs are most common, there's often a random factor (sometimes rolled each level, sometimes one-off). HERO and 4E GURPS I think let you 'buy' HPs separate to any other stat . There are also games which just give out fixed numbers of hit points, and there may be class modifiers. Some games (Runequest) have a Size value separate to Strength which affects hit points. Very occasionally Willpower or Dex affects hit points, and I can think of one (MSH) where 'Fighting' is a score and helps calculate hits. There are a few games where some mystical or metagame resource is more important than actual HPs; in Savage Worlds characters spend 'bennies' (luck points) to soak so these are very important, while Exalted characters have a wound track but mostly rely on spending energy motes to power Perfect Defenses that block attacks.
Strength as a source of HPs is probably most justifiable as a rough measure of size, though to an extent muscle is also harder to cut through and so armour a character's vital locations. (I guess fat might help here too...). Response to blood loss is perhaps more a Con thing, however, perhaps bone density as well. Poison tolerance depends a lot on body mass so you could argue STR would help there (as an abstraction of body size), as well as CON, though I don't think working out would help much. Having STR as basis for HPs is bad for swashbuckly-type fighters, although maybe more points in DEX will help them from being hit as often.

As far as scaling goes, depends what you want. D&Ds 1 Hit Dice/level thing is good for heroes killing lots of low-level plebs, though you could also have some sort of damage bonus for high-level vs. low-level characters, or high attack roll vs. low defense.

On the bending bars/break down doors, 3E just has Strength checks (d20+Str modifier, + size modifier in this case), with a DC depending on what you're doing.

Thanks for the link, i gave it a quick perusal, and i'll have to look at it again in the daylight hours. Very interesting read what i saw.

I agree with you on the Swashbuckler point, i've never considered them to be strength based anyway, more dexterity/agility fighters.

I'm thinking of the swordsmen in the Princess Bride for example. It was never about their brawn or toughness, it was about their speed and accuracy. When Wesley was tortured, what kept him alive wasn't his strength or body, it was his will to live (in game terms, his Vitality). Just a thought.

Or Inigo fails to die due to his 'overdeveloped sense of vengeance'

With Willpower, one idea I've toyed with is having HPs determined by CON (or ST), but having willpower rolls start becoming involved to keep going at negative HPs. In that setup wound penalties and critical effects and such would be based off actual HPs, but Will would still make some difference.