I want to preface this by saying that I'm aware of how contradictory it sounds to apply real-world logic onto something that is inherently supernatural in a supernatural setting. Saying that, I like to believe that there is a sense of satisfaction that can be found in writing something supernatural that is as close to reality as it can be!
How does someone reason magic to work as a substitute for lack of physical ability or attain superhuman strength with magic? What is the magic supposed to affect: the cells of the character? The space around the character? A mix of both?
I know I'm just throwing out questions, but I have a hard time visualizing how to attain superhuman strength using magic.