You can tell a group got improvised training because they will absolutely marvel at the luxury of well funded professional teams and arenas. The richer, posh kids will sneer at them, while these kids will reply they didn't need sissy advantages or buy success with money.
Despite the zero budget and dubious training methods, it turns out the rougher and unconventional training pays off and helps them win. The more traditional (especially the ultra well funded prep or snooty Legacy Team that always wins) will have such rigid and inflexible mindsets that the ragtag team keeps catching them by surprise. Be it with creative plays or enduring more pain, or outperforming them. Occasionally, the training itself may even give them comparable or superior physical performance, at times bordering on Charles Atlas Super Powers.
- Subverted in Rurouni Kenshin where Sano (a brawler) attempts to train while traveling to Kyoto by knocking down trees with his bare hands. Eventually however he admits, that this isn't really training and he's not learning anything useful by doing it. At least while he's lost in the forest he does meet a mentor who does train him and show him new techniques.
- Eyeshield 21 had this trope going in the beginning. Ojou were so luxurious they owned a castle in Germany for the sole purpose of training in it. Deimon? They pushed a truck half way across the US in a month (part of the reason was also because they didn't have enough money for more gas).
- Endou from Inazuma Eleven usually practices with a tire tied to a tree, which he tries to stop with his hand.
- The Turtle Hermit trains Goku and Krillin in Dragon Ball by having them deliver milk to an entire island every morning, plow fields with their bare hands, dodge bees after hitting beehives, swim in a lake with a shark in it, do construction work, etc. All with a 40 kg turtle shell on their backs (that gets doubled in weight a few months in).
- In Amazing Fantasy, Izuku spends ten months following Peter's training plan, which is designed around discovering and pushing the limits of Izuku's abilities in a program entirely sustained by Izuku's allowance. This includes taking laps around the city, setting up improvised obstacle courses to practice parkour, and using abandoned roller coaster cars as weights. He slam dunks the U.A. Entrance Exam even without access to his web-shooters.
- In Neither a Bird nor a Plane, it's Deku!, Izuku can't use his powers in public, so he needs to find a place away from prying eyes that he can access on a daily basis to practice. He decides on Korusan Island, the corpse of an abandoned Kaiju that emits a gas so corrosive that no one else can approach it without dying. There he refines his control over his Combo Platter Powers well enough to easily earn a spot at U.A.
- A Knight's Tale They used jury rigged contraptions to teach William to joust. Plus he had to wear a dead guys armor.
- Cool Runnings has the story of the first Jamaican bobsledding team. With such gems as "sliding" on a cart down rocky hills, and locking players in an ice cream truck to acclimate them to the cold.
- Shaolin Soccer, a washed up pro soccer trainer converts a team of washed up kung-fu trained brothers into a team of Super Soccer Kung Fu Monks. With such feats as eggs tossing and catching, and pitting them against a team that uses metal hand tools to bludgeon their opponents.
- In Lagaan the new Indian cricket team chases chickens and the like. Half of their special skills originate from ordinary tasks that they do in their day jobs too.
- The little league baseball team in The Perfect Game. They're poor, have no advantages, and actually have to clean up a church yard of brush, tires, and rocks to get a ball field. Their training consisted in a lot of running, cutting their own bats from wood, and hitting balls made of rubber bands/wire. They do eventually get real bats and balls, though they never see cut grass fields until they start competing.
- Rocky does a version of this in every movie, chasing chickens, using whole cows as heavy bags, lifting logs, etc., usually done to an 80's Sports Montage. In Rocky IV his working out was juxtaposed with his opponent's high-tech training, contrasting Rocky's lifting boulders and chopping wood to Drago's using high-tech equipment with dozens of scientists surrounding him.
- A variant in Major League sees the ball players improvising ways to recover from the exertions of training, after the team's hostile owner takes away all their equipment. One player is seen lying in an improvised whirlpool bath made up of an aluminium horse trough, a garden hose, and an outboard boat motor.
- The old children's book A Brother for the Orphelines by Natalie Savage Carlsson is about a bunch of girls in an orphanage where this turned up — the girls are able to beat the other local kids at marbles because they can't afford marbles themselves and so they always play with walnuts.
- Subverted in Unseen Academicals, in that Trev Likely can manipulate a kicked tin can six ways from Sunday, yet has never actually kicked a soccer ball in his life. When he finally does join a game, he can only manage near-miss shots until a friend engineers a "lost" ball and tosses a tin can onto the field as a substitute.
- In Firebird (Lackey), when posing as a mad fool and dead bored, Ilya improvised training to keep fit. There's a notable passage of the book that makes perfect sense in context of a life of extreme physical labor, but is sure to make anyone who's run track double over laughing:
Besides, it was perfectly mad to run circles around the palace. No sane person would waste his time running for no other reason than to get exercise.
- In Ballerina, wagon wheels and water barrels serve for the orphans vestibular training.
- British climbers Tom Randall and Pete Whittaker built a plywood training dungeon in Tom's basement where they spent two years training strength and endurance before embarking on a two month tour of America's offwidth crack routes. They swept through most of the classic routes, then climbed the infamous Century Crack making themselves legend in the climbing community. Their training montage is filmed in Reel Rock Tour 7.
- Kolten Wong, the second baseman for the St. Louis Cardinals (as of 2019), grew up in Hawaii and strengthened his baseball swing by chopping down trees with an axe.