No. Turning the caber is an individual event.
It can damp down or hamper movement.
Target shooting (and I’m specifically referring to rifle, which is the only kind I did) is a precision sport. I’m trying to put a .22 calibre round through a bullseye that is the size of a dime, at a distance of 50 meters, and using only iron sights (i.e. no telescopic sights). A twitch, “the shakes” from too much coffee that morning, or other unwanted or involuntary movement, could throw my aim off, so we can damp down any effects by using thicker clothing.
Think of Ralphie’s little brother in the movie, “A Christmas Story.” Every time he goes outside, he is dressed in so many layers of clothing that he cannot move. And if he falls over, as he often does, he cannot get up–all that clothing means that he lacks the flexibility to get up. The same principle applies to target rifle shooting–the more and thicker your clothing, the stiffer you get, and thus, the less susceptible you are to unwanted or involuntary movement. So, to level the playing field among competitors, the rulebook has parameters your clothing must fit within.
My typical attire for a match was a cotton T-shirt under a thin flannel long-sleeved shirt. The combined thickness of both was within the rules, but a thicker flannel shirt or another T-shirt, would have disqualified me. My jeans and sneakers were easily inside the rules. I also had my leather shooting jacket, which was designed by the manufacturer to conform to the rules, and said so on the label. Of course, I always had my shooting glasses, for safety’s sake.
King of the Hill had a pretty great gag where Dale cheats at a fishing competition by having someone underwater place a large bass they had already purchased from a local fish market onto his hook and he reeled it in.
His only problem was that the fish was still frozen when the official weighed it.
Even aside from taking banned substances, it would be possible to cheat at curling. It’s rather like golf in that players are expected to call fouls against themselves. If you’re sweeping and your broom happens to touch the rock, you’re expected to announce it and take the appropriate penalty. The officials that you see in televised matches do very little, until they’re called on for something the players can’t agree on among themselves.
There are probably other ways to cheat, if you put the effort in. It doesn’t take much to throw off the line of a curling stone. You could drop things on the ice to try and disturb your opponent’s shots, or alter your broom to make it more effective.
Ping pong?
Yep, the ice surface is critical and a scratch, piece of lint, a bit of water, salt, sand, etc… can cause a pick and cause a deviation in the path. It happens quite often in regular play.
Would faking an injury to game the rules, which happens in soccer and Football, be cheating? I would say yes but some people would call it “angle shooting” (i.e. using loop holes in the rules to your advantage).
It’s definitely cheating (most commonly, exaggerating the extent to which you have been touched by an opponent in the hope of getting the officials to sanction them). This isn’t a loophole in the rules because there isn’t anything you could put in the rules to prevent it, all you can do is try to punish those who appear to be guilty of doing it.
It’s definitely cheating. If everyone fakes injuries then after a time it gets hard to distinguish fake and real ones. Eventually that may lead to serious injuries not receiving needed and timely treatment (the crying wolf syndrome).
Another way to look at it, if your strategy requires deceiving the officials it’s pretty much cheating by definition. (Deceiving your opponent is generally just being clever.)
They use observers, which is all but the same as officials.
That actually happened in tournaments, as well as anglers stashing precaught but live fish on the lake and taking them out of the underwater cages, pretending they’d caught them during the tourney.
I nominate Mornington Crescent. And Calvinball.
Um, it’s the fourth Wednesday of the month - you can’t mention Mornington Crescent in odd-numbered posts. Check your rulebook - I hope you’re not still using the hopelessly outdated Cunningham edition? Some would say this was cheating…
ETA: I think I see where you erred - had you forgotten that GMT is (for obvious reasons) always used? So probably not cheating. But it could have been.
If you’re playing on-line (so can’t sneak pieces on the board, etc.) you could intercept your opponents’ electronic communications to read their orders or communications to each other. That would be a significant advantage, I think.
Solitaire? 
That sounds pretty hard to do.
Darts, and other non-contact target sports like bowls etc.
I found one incident of apparent cheating in darts, which involved a very close miss, the scorer misreading it and the player (who must have known the call was wrong when he stepped to board to retrieve the darts) keeping his mouth shut rather than correcting it. That was in 2013. It required a fairly unique set of circumstances and you certainly couldn’t plan on doing it with any success.
Which isn’t to say there isn’t a certain amount of gamesmanship: playing slowly to put an opponent out of rhythm, “sledging” via quiet asides and even on one occasion deliberate obnoxious farting (!). But I think those come under “bad attitude” rather than out and out breaking the rules.
Other than that, I think it’s quite hard to cheat. You could overstep the oche to be closer to the board, but if you’re over enough to help you’ll be spotted, and if you’re not over enough to be spotted it won’t help. There might be some sort of superior but banned type of dart* but failing that you’re left with some sort of ludicrous cartoon-physics magnetised board and darts arrangement which would be both difficult to arrange and supremely unlikely to actually work.
*There’s one word for that: magic darts
Are there ways to cheat in competitive eating (pies, hotdogs, etc)?
Curler here.
If you’re playing competitively, using a curling broom with a head that can scratch or melt the ice in a way that changes the direction of a rock much more (Hardline IcePad, Goldline Norway Pad, old horsehair broom, etc) than using conventional head, isn’t allowed. For club play, it’s okay, but you might get a few dirty looks among hardcore curlers in Alberta or Duluth. You could probably modify a conventional broom head to hide some handwarmers for something similar.
There’s also not calling burned rocks (when you touch a moving rock after release) or hogged rocks (delivering a rock, and holding on to it past the hog line). Mulligans aren’t a thing in curling.
Otherwise, you don’t cheat at curling. It’s just not part of the game. The winners buy the losers drinks, so there’s not much of an incentive to cheat in club play.
Have a labrador under the table.
It’s absurdly easy to cheat at solitaire. You can, for example, just search through the deck for every card you want and place them however you like. There are rules to it (or it wouldn’t be a game) and there’s nobody to call you on it when you break them. Sure, you get nothing out of cheating since there is no opponent to beat but cheating is cheating.
It reminds me of one of the saddest things I’ve ever encountered in my life. Back in high school there was a kid who used to play Dungeons and Dragons in a solitaire fashion. He was his own Dungeon Master and would run his own PCs through scenarios he made up. That on its own is sad enough but the worst part is that he’d brag to me and my friends (who played RPGs together on occasion) and regale us with his accomplishments. He’d talk about how strong his character was, how he’d defeated all these various gods in single combat, and so on. He truly expected us to be impressed by the way he’d sit alone in his room and just make up stories by himself.
I bet he grew up to be a serial killer or something.