Talysman posted a meditation on hit points on Sunday.
I've always understood hit points to abstract not merely bodily intactness, but also stamina, luck, concentration, and so forth.
On page 18, Men & Magic defines hit points as
"the number of points of damage the character could sustain before death. Whether sustaining accumulative hits will otherwise affect a character is left to the discretion of the referee." The description for Cure Light Wounds says the spell
"will remove hits from a wounded character[....] A die is rolled, one pip added, and the resultant total subtracted from the hits points the character has taken." That would seem to establish a very narrow definition of hit points indicating a capacity to survive wounds, and not a measure of stamina, luck, etc.
However, a few other passages in the LBB's hint that hit points may sometimes reflect more than wounds. The description for wights says they
"drain away life energy levels when they score a hit in melee, one level per hit. Thus, a hit removes both the hit die and the corresponding energy to fight, i.e. a 9th level fighter would drop to 8th level." The wight description is interesting for two reasons. First, it could be read in conjunction with the Cure Light Wounds description (
"will remove hits") to mean that Cure will "remove hits" inflicted by the wights, and therefore restore the drained level* caused by those hits. Second, the wight description links "hits" with "energy to fight".
Hit dice dictate the number of creatures affected by Sleep. Sleep does not wound the targets, so that too indicates hit points/dice measure something in addition to the capacity to survive wounds.
Perhaps the most direct reading is that hit points correspond directly to the capacity to sustain wounds, but it's possible to understand some passages to mean that hit points/dice sometimes represent other concepts. I tend to favor the latter reading. Practically speaking, an experienced combatant may to some extent be able to mitigate wounds (maneuver to take a bruise to the shoulder instead of a slash to the ribs), but they'll certainly be better conditioned both mentally and physically to the rigors of battle in terms of stress, fatigue, and concentration.
* Although page 35 of Underworld & Wilderness Adventures says
"energy levels can only be regained by fresh experience, but common wounds can be healed with the passage of time".