It depends on what you're building stamina for and what you're willing to lose in exchange for stamina.
If all you want is stamina and you're fine with losing strength in exchange for stamina you can do a marathon runners workout. This will give you the sorta body where you can run and keep on running and running using minimal energy basically, but you're not as strong as you could be.
If you want stamina to do MMA cage fights it's a different story. A marathon runner is running about 10 miles a day in preparation to go and run 26 at once. MMA fighters and boxers are trying to have stamina to take a hit and keep on standing.
A good method for boxing and mma is to do exercises in rounds. Say you're in a league with 3'00" rounds and 5 rounds with a 1'00" break between rounds each match. A great way to build up stamina for that is to go work on the heavy bag for 3'00" as hard as you can, take a 1'00" break, then move on to the next workout for 3'00" with 1'00" breaks inbetween at the start. Then push it up to eventually 5'00" rounds.
I did track n field, wrestled, played soccer, football, and tennis. These sports have different stamina requirements. I'll cover what I did to prepare for each and why they are different also their similarities.
Track n field, my first sport.
I competed in the 800m dash, 400m dash, 4x400m relay and long jump [which required less work and took less out of me at an event]. At a meet I was going to competitively sprint full speed for 800m [400mx2] and at about 70% full speed for 800m and then jump as far as I could 3 times.
To build stamina for this I did a lot of sprints and ran miles. For the 400m dash sprinting 600m's and giving it your all will build stamina for running 400m. For the 800m you need to run 1600m [a mile+100m basically] intervals along with 300m, 200m, and 100m sprints to prepare for it. Basically you need to balance so that you can sprint hard and fast but you also have the stamina to keep going. In order to prepare for a meet where I was going to do 3 physically demanding events I had to work out pretty hard monday-thursday and then friday was a pretty light workout and we ate a lot of pasta and carbs to store up some energy so when our event came about on saturday were had the energy to burn for our races.
storing up energy the day before the event is a pretty common thing in terms of stamina.
45 minutes halves with a 20 minute break in between them. For 45 minutes you are sprinting, jogging, but sometimes just standing in place or walking. To prepare for this we'd do a drill where you have to make it to the end of the field and back 20 times in 20 minutes because you're likely going to have to do that in the game anyway. We ran on 4 mile runs everyday and did 20 40 yard dashes as well as 10 full field sprints each practice. I personally would go and go 30 more full field sprints, and run 3 more miles when practice was over and I never sat on the bench because I was never tired enough to need to. This is a bit different than track because it's not a specific amount you'll be sprinting each game trying to beat your last time as much as a utility to make it to the ball or a place you're needed on the field and you're also getting knocked down.
We practiced sprints full field and 40 yard dashes. 40 because you're likely never going to need to run more than that in a game. We occasionally would run a mile or 2, but distance running isn't as important in a sport where you take a break and get some rest after ever play and then even more rest when someone scores or there's a turn over. So, the main thing was to practice taking and giving a hit and sprints to increase stamina with about 5 miles ran a day... nothing major.
This is a very different kinda stamina than track, tennis, and soccer. We ran for timed runs of 30 minutes to be able to endure doing something for a set time, like the match time. We also slammed ourselves on the mat to get used to being slammed on the mat.
like basketball this is mostly about doing sprints. In practice it was sprints and suicides. Cause in a match you get a small break between each point but it's mostly just suicides the game.
I feel like the point of a community is to help where/when/however u can.