Some people have genes that make them naturally stronger, according to a largest-of-its-kind study of more than 340,000 people in Finland.
In addition to having a solid foundation for building brawn, individuals with the highest predisposition to hand grip strength were found to have up to 23 percent lower risk of common diseases, and a longer life expectancy.
The study's findings suggest that personalised genetic details on muscle strength and weakness can help doctors identify who is at risk of certain health conditions.
I don't feel like Korra's raw strength is talked about enough. She picks up this full grown man with basically no difficulty!! It should be noted that the Avatar state does NOT affect physical strength, only bending strength. Plus she goes out of the Avatar State while she has him up in the air anyways!!
There are a lot of really good examples of her physical strength throughout the show but this one's probably my favorite because it's just so ridiculous and blatant
Here's a couple season one examples just for the fun of it