A couple thoughts on this one (and keep in mind this is from someone who missed out on this in PE class)...
It's interesting seeing how early jocks were required in some schools, but it may not have been impossible when you consider youth sizes. I think the typical youth regular/medium was for 20-26" waist, with large running 26-32", or at least versions of that. Looking around ebay, it seems like Bike even made a Youth Small in the 1990's (guess at the date) - it shows this as 14-20" waist, which is TINY!
Size Small waist 14" - 20".www.ebay.com
It's also wild to hear that cups were even required in PE, although there were certainly days where they would come in handy depending on the sport being played!
I would also add, in looking around online, seems like there are at least some hits still of schools which require or recently required jocks for the boys in PE. Interestingly enough some of the same webpages sometimes also require or recommend sports bras for the girls - honestly these two seem like they'd go hand in hand. I would guess the sports bra requirement is on the rise, while jocks are (and have been) on the fall.
SMALLER POUCHES Especially for youth.
In my town they required jockstraps for PE in 7th grade, because a few guys were starting puberty. Many of us chose to wear them earlier. We couldn't wait to be like the big guys. We never thought that our small pre-puberty stuff disqualified us. We were "superman" in our hearts.
In our little town the only store that sold gym clothes had BIKES in all the adult sizes. So the smallest we could get was ADULT SMALL. This was really stupid because the pouches were ample for the most hung adult and us boys were swimming in the pouches. I tried real hard to snug them up. In hindsight I am puzzled that the store owner never offered us kids the YOUTH sizes, and the school coaches who saw the discrepancy never said anything.
When I was 14 and my nuts got big I was in Jr High. One guy with the locker next to mine was the only guy in the school to have a YOUTH MODEL. His dad took him to another town to get it. I memorized his locker number and "borrowed" it one day. I was in heaven wearing a jock that actually cradled my nuts. I wore it to bed and had two wet dreams. I returned it to his locker before gym class. At that age I didn't think anything about the loads I shot in it, but I am sorry about that now. That wasn't nice.
It seems unfair that so much attention is paid to girls to get them bra sizes that fit them individually, and they even have "training bras" for those who haven't "bloomed" yet. While all boys are expected to wear ADULT MEN'S pouches that didn't really help us any. Once a guy reaches puberty, whether his cock and balls are small or larger, no one wants then dangling during competitive sports. We all need support. Why can't jocks have pouch sizes too? They could label the pouches "snug" or "roomy".
Before BIKE stopped making jocks, they made a wide waist band model for TEENS LARGE that came with a large enough waist band that I could just get it on. I loved the smaller TEENS pouch. It gave me great support. If you look at my avatar photo you will see that I am NOT in the small range, and yet a snug pouch was just right for me, as long as I wasn't hard. (Getting a boner in any jock is painful for me.)
So, I think that pouches are too big especially for boys and teenagers who need their own sizes.
I attached a photo of a jock with the snuggest pouch I ever found. It lifted my balls up front and grouped everything together real good. It feels fantastic. Unfortulately when I tried buy another they had discontinued them.