Underwear suggestions...
My issue with most of the boxer-briefs I've tried is that they always start riding up my legs, so then I end up with a bunch of wadded material up higher on my leg, not getting any real support. I've tried Under Armour and a couple of other brands that I can't recall, and they all do the same thing.
I've switched to wearing compression pants that go down past my knee when I go to karate. This gives me good support, and they don't have a problem creeping up my leg. I'm starting to develop loose skin in my thigh area, and it really flops around when I'm trying to kick if I don't have it locked down with a compression layer under my uniform. My favorite is made by Sub Sports:
https://www.amazon.com/gp/product/B003TOBORW/ref=oh_aui_deta ilpage_o09_s00?ie=UTF8&psc=1
The material feels great. I've only worn them a few times so far, so I can't speak yet to durability, but they are pretty well reviewed and I think pretty affordable compared to some of the bigger name brands out there. They also do a version that might meet your boxer-brief type criteria here:
https://www.amazon.com/gp/product/B002VE4UMW/ref=s9_acsd_al_ bw_c_x_3_w
Just note - the package I received came from Germany (even though it's free shipping on Amazon), so it takes a little longer than a usual Amazon order to arrive.
My hubby refuses to wear anything but saxx underwear since I got a pair as a gift. They are pricey, so he gets a pair for every gift occasion. I don't know what makes them so special but even the sales lady commented to me that she doesn't know what is up with them but her boyfriend is the same...will never go back to anything else once he tried them. And they sell like hot cakes
Band-RNY revision age 50 5'4" HW 260 SW: 244 (bf healthy range 23-35%) bf 23.7% (at 137lbs) cw range 135-138.lbl with butt lift and mastoplexy March 23, 2018...2.5lbs removed.
Pre-op-16lbs (size 18/20...244) M1-16lbs (size 18...228) M2-15.6lbs (size 16/18...212.4) M3-10lbs (size 16..202.4) M4-11.4lbs (size 14...191) M5-10.8lbs (size 12...180.2) M6-8.4 (size 8/10...171.8) M7-6.4 (size 8...165.4 lbs) M8-11.6 (size 6...153.8) M9-5.6 (size 4/6...148.2) M10-5.8 (size 4....142.4) M11-4 (size 2/4...138.4) Surgiversary -1 (size 2/4...137.4) M13-2.6 (size 2/4...134.8) M14 (size 2/4...134.8) M15 (size 2...135) M16 (size 2...131.4) M17 (size 2...135) M18 (size 2...135) M19 (size 2...138) M20 (size 2...135) M21 (size 2...138)