The purpose of gym class — also known as physical education — is to encourage kids and young adults to be physically active. And for some people, it works.
By "some people" I mean the ones who like and/or are good at sports. Usually and. Because people who aren't very good at sports will learn to hate them very quickly in gym class.
When I was taking gym class it always focused on sports — partly due to a misguided belief that all children like sports, partly due to funding (a single soccer ball, or a few basketballs are much less expensive and easier to maintain than a rock climbing wall, or weight machines), and partly due to having teachers who weren't always very well trained trying to teach groups of 25-30 kids at a time, so that they can't really give proper instruction in anything. Because apparently gym is like English; anyone can teach it. (What are "credentials"?)
The only times I liked physical education were when we were doing gymnastics, and for the part of track and field when we were doing high jump — up until I injured my knee in grade five or six, after which high jump was painful and also frustrating (because I used to be moderately good at it and then no longer was, which is infinitely worse than just always having been terrible).
Making physical education about sports makes it about winning and losing. And when it's about winning and losing the people who aren't personally as good at it end up hating it; not necessarily because they're not good at it (I was never great at rock climbing, and there were always going to be tonnes of people who were better than I was, but I still loved it and I’d still like to get back to it if I ever can). No, they end up hating it because it's a way to let other people down.
And for some of the people who are good at sports, and are also sensitive to other people's feelings, competing with or against people who aren't evenly matched skill-wise can be upsetting because they worry that they're making their teammates or their opponents feel bad. This may be unlikely with grown-up athletes, but remember, we're talking about school kids, ages five to eighteen. And the under-tens mostly haven't learned to not give a crap about others yet.
So, gym class was terrible and I avoided it at all costs. If we were playing dodge ball I would sometimes intentionally get hit so that I could sit out until the end of the round.
As soon as it was no longer mandatory I dropped gym class like it was a priceless Fabergé egg that my worst enemy had asked me to hold for them. And most of the extra-curricular physical activities that I knew about and could have taken part in were far too similar to gym class. Between the ages of four and nine, I really enjoyed figure skating and was devastated when my mother stopped signing me up. Then I tried to go back in my early teens and learned why mum had stopped the lessons — once you reach a certain level it becomes all about competition, and if you're not interested in competing then coaches (in my experience) aren't interested in you.
It's not like I never did anything physical. When I aged up into Rangers (Girl Guides for fifteen- to eighteen-year-olds) we went on a lot of backpacking trips, as well as canoeing, dog sledding, and other fun things. It was actually at a provincial Rangers event that I first tried rock climbing.
But I didn't consider any of those things to be physical activities; hiking and dogsledding were adventures or experiences, and rock climbing was a skill that I was building, like knitting or cooking. And when I first started going to the gym and lifting weights it was in an effort to become a better climber, not because I wanted to be healthier.
Physical education had so thoroughly convinced me that I hated physical activity that I avoided anything I perceived as such; and if I accidentally tried and liked doing something physical, My Brain would categorize it as something else. Anything else.
In gym class I liked when we would do dance, but that was ART.
I liked when we would do gymnastics, but that was a SKILL.
I liked when we would do skipping, but that was a GAME that I'd been playing with friends since I was little.
Basically, I liked all of the things where I was working on my own. Where I could look more at my own progress, and less at what others were doing or expecting me to do. Where no team was counting on me, and therefore no one got mad at me when I did something "wrong". If I made a mistake in group skipping that just meant it was my turn to hold the end of the rope while other people skipped — people were more likely to get annoyed if someone was too good at it and never did the "boring" job of twirling the rope for everyone else.
I'm not suggesting that we cancel gym class. I think that its theoretical purpose of getting kids moving is a fundamentally good thing. I'm suggesting that we change gym class, and try to foster actual enjoyment of physical activity (the current model fosters avoidance — how many people did you know who would use any excuse they could come up with to try to get out of participating in gym?)
I think that cooperative games would have been more universally enjoyable than competitive ones. I think that learning about proper nutrition and how to provide first aid would have been far more beneficial than learning the rules of a bunch of different sports that I not only didn't enjoy playing or watching, but toward which my feelings about playing or watching were (and still are) the diametrical opposite of enjoyment.
In highschool there should be two different gym classes; one for the sportsy kids, and one for the kids who prefer individual activity. And if some kids want to take both then that's awesome! But teaching kids to hate physical education teaches them to hate being physically active.
And that's just not good.