Realism... to me, as it applies to stories, this does NOT mean real events, people, etc... but instead means that nothing is fantastically different from modern standards... ie no centaurs, no blue skinned aliens, etc.
So, when reading a story that otherwise shows realism, it is jarring to read character descriptions that show little resemblance to reality.
Case in point: MC is described as 6'3", 190 lbs, muscular and ripped from his exercising (100 p/u, 250 s/u, 5-10 mile run, 1/2-1 mile swim daily).
Using my physique as a baseline for reality: at my prime, I was 6'1", 190 lbs, thin and wiry.. certainly not ripped nor muscular. Some seriously thought I looked anorexic.. I had very very low fat reserves...in fact, I barely registered using body fat skinfold measuring devices. I was also constantly borderline dehydrated as I drank nothing but sodas.
4 primary areas control weight: muscle, fat deposits, water retention, and bone density.
Muscle is a lot denser than fat deposits...so for the same weight, muscle will have a leaner look and occupy a smaller area.
Bone density is relatively standard... but you do have outliers that are very delicately boned or very thick-boned.
Water retention is pretty standard (for males, I know that for females it depends on their hormonal balance at the time in addition to any outside influence) unless you are over-watering or dehydrated. The higher your water retention, the more you weigh if all other factors are the same.
So... comparing that MC's description to mine and taking into account the factors involved in weight... I can see absolutely NO way in hell a male could be described that way and only weigh 190 lbs.
In my prime I was 2 inches shorter, same weight, with normal bone density and borderline dehydrated (if I hydrated to normal levels, I would probably have weighed 5-8 lbs more than I did).
The MC is never described as having very delicate bone structure so I assume he had normal bone density. Even if he did have very delicate bone structure, it wouldn't account for the weight disparity...not unless he had hollow bird bones which would not be able to support that amount of muscle mass without collapsing anyway.
IMO for a male with height of 6'3" to be described as ripped and muscular would have to have a weight of 230-240 lbs (or more depending on HOW muscular) to be realistic.
Just a pet peeve of mine really... every time I read a story with a male description like that, it is very jarring because I was constantly harassed/made fun of for how thin I was yet here is a description of a character even taller than me and the same weight that is described as ripped and muscular when the additional 2 inches would have made them appear gaunt and wraithlike. My brain can't come up with a visual that fits the description when I am reading because it goes so against my experience... it is like reading "the water felt dry" and trying to imagine that. I have a very rich imagination and usually can easily visualize anything I am reading...so to have a description come up that gives me a total blank on a visualization is enough to totally throw me off balance while reading a story.