Why would that be racist? At any rate, Redguards aren't the only one with athleticism as an ability. In Morrowind, for instance, they get +5 to their Athletics skill, but so do Dunmer and Khajiit. Argonians get +15!
wait why is that a bad thing? Am I missing something? Since when was being physically capable considered insulting?
This part of the lore was written in 1994 when they first released Arena, and introduced all of the different races. If you look at the artwork and writing for that game and Daggerfall, you'll notice Elder Scrolls was pretty knee-deep in quasi-racist/sixist fantasy tropes, as well as just being a pretty generic fantasy universe to begin with. It wasn't until Morrowind (or more specifically, Redguard) that they moved in a new direction to make the series more unique and flee from those tropes, although they tried to avoid retconning most of what the first two games established. So no, no one making the gladiator game turned Tolkienesque/DnD-esque fantasy RPG from 1994 realized they were perpetuating a stereotype, although I'm sure they picked up on that later on.
Although if you actually play the games and observe all of the Redguard characters, they pretty much run the gamut of character types and personal ability - one of the advantages of the modern Elder Scrolls games having so many different NPCs is that there's never a token black/female/whatever character, and they can avoid those stereotypes pretty easily. The lore around Redguards also paints them as the most clever of the "warrior" races, as well as masterful artisans, craftsmen, and seafarers. It's a shame the Redguard adventure game never got much traction, I can't think of any other fantasy adventure games with a primarily black cast of characters.
The "black people = more athletic" stereotype actually isn't supported by science, although it's got an ugly origin in slave-era pseudoscience, and it's managed to persist ever since. It's kind of super-complicated, and this isn't the forum to go into that discussion. The only thing that really upsets me about how Redguards are portrayed in the modern games is that Skyrim used mostly white voice actors to play the Redguard characters - I mean, Jason Marsden is great, yeah, but what's up with that.
As mentioned above, these kinds of statements tend to originate more in prejudice inspired pseudo science than real biology. I would be more dubious of such "facts" if I were you. Anyway, back to Elder Scrolls. I don't think the redgaurd athleticism bonus was ever intended to be based on real life physical stereotypes, but rather a reflection of their warrior culture. i.e. Redgaurds tend to be more athletic because they put more emphasis on physical training than, say, High Elves. It's still a generalization even in that context though.
I think when people see "racism" everywhere like this, it says more about them than the things they're actually critiquing.
The Redguards are known for their aversion to magic and their sword-fighting prowess, so it makes sense that their racials are centred around physical ability rather than, say, resistance to or affinities with certain magics.
It get far worse, Argonian and Khajiit has tails no others, this is pretty visible.
There is no race on earth known as Redguards. There is some racial generalizations that are apparent in Nirn. We get into trouble here when mixing up earth and Nirn. One easy way to ensure you realize this is not earth is to notice the two moons that orbit Nirn and the beast races. Here on the forum we tend to get into trouble when trying to compare this fictional place with it's fictional races to earth.
So we don't do that, I think this thread is best just closed. It's important to keep real world politics, religion and prejudices out of our discussions of Nirn and it's inhabitants.