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gudamor t1_j1n40eq wrote

"we tested 20 things, but only this one was significant at p<0.05"?

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chance909 t1_j1oiyl9 wrote

From the statistics textbook:

"With 20 tests being considered at a p-value of 0.05, we have a 64% chance of one test being significant even if all tests are actually non-significant"

If you have multiple testing, you need a correction like Bonferroni or FDR to avoid this issue.

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potatoaster t1_j1o4xis wrote

Wow, you're right. I read the paper fully expecting them to write something about multiple comparisons but nope, there's nothing at all. And the p value that made it through that barrier of probability was .02. Naturally.

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popplesan t1_j1pegew wrote

It’s an MDPI paper, can’t expect much. I read a paper in one of their journals that explicitly described p-hacking in the methods. The reviewer’s comments were public, except they had no comments. It was mind boggling. Then I saw that the advisor had 100+ papers in sketchy journals, was at a fairly weak university and decided to Google if MDPI was a conglomerate of fake/predatory journals. They’re in a gray area for sure. Some of their journals are laughable, and some are pretty decent. But as a rule of thumb, if I see MDPI I bust out the fine-toothed comb even from their good journals.

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B_lintu t1_j1qo7gn wrote

Wow that's so effed up. I was recently reading one of their economics journals with 3.9 impact-factor and I would never think such things would slip in this kind of journal, I though it was quite decent.

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cantdecide23 t1_j1ozg76 wrote

As a volleyball player this kind of confuses me too, in the sense that they say it improves attacking, but then proceed to list off all the components that make up an attack (running to position, jumping, hitting, etc) as things that are unaffected.

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Altiloquent t1_j1n5unr wrote

So they did at least 8 comparisons on the data and found one was significant. Shouldn't that p value be adjusted, especially since they didn't find significance on measures that were previously reported?

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glawgii OP t1_j1mkdf2 wrote

>Caffeine is considered the most popular psychoactive drug used by the majority of the general population in the world. Due to its ergogenic effect, it is widely used by athletes of many sports disciplines.
>
>Interestingly, between 1984 and 2004 caffeine was banned in sports competitions, although only in extremely high doses (i.e., representing a concentration of caffeine greater than 12 μg/mL in urine). However, on 1 January 2004, the World Anti-Doping Agency (WADA) decided to remove caffeine from the list of banned substances. Since then, athletes can freely use this substance during competitions. Nevertheless, caffeine has been moved to the Monitoring Program to control the consumption of high doses of caffeine by athletes (i.e., over 6 μg/mL in urine) as they can be harmful to them.
>
>Interestingly, a urinary caffeine concentration greater than 15 µg/mL is still prohibited by the National Collegiate Athletic Association (NCAA). However, since the ban was lifted for almost all associations, caffeine-containing supplements have been hugely popular in the sports world. It has been shown that up to 75–90% of athletes use caffeine before or during competition. The recommended doses of caffeine intake by athletes are 3–6 mg/kg body mass (BM). This is due to the fact that higher doses of caffeine (9–13 mg/kg BM) do not result in additional benefits, and also increase the risk of side effects.

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mjkjg2 t1_j1mxm2x wrote

would like to see this with nicotine gum too

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TheLoneJuanderer t1_j1o28uf wrote

I was curious too, so I looked it up. Apparently the evidence is pretty neutral for nicotine, but also, the amount of research is very limited currently.

It’s actually not prohibited by WADA, which is interesting, but I guess nicotine research isn’t very popular these days.

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laustcozz t1_j1pb54v wrote

Released research on nicotine is limited, that doesn't mean the research actually is. You can bet your heiny if there were significant positive effects there Phillip Morris would have let you know about it decades ago.

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SheepChaser1 t1_j1o1nry wrote

I bet it has a similar effect and I would imagine it’s due to saccade.

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Ruhh-Rohh t1_j1n1u5c wrote

Gag. Ever had a caffeine pill melt on your tongue? Now think of doing it on purpose, for an extended period of time.

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TheLoneJuanderer t1_j1o0zql wrote

I was about to say that caffeine infused gum tastes mostly normal, but then I read what they actually took in the study: For men it was about 6 portions of gum totaling 300mg of caffeine. Basically 5-6 cups of coffee’s worth of caffeine.

Yeah… “gag” is probably the correct reaction to this…

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BadMeetsEvil24 t1_j1ozvj5 wrote

You're saying one cup is equivalent to 50mg of caffeine? I thought one cup was commonly equivalent to 100mg.

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TheLoneJuanderer t1_j1p4eff wrote

Sorry, I was thinking like espresso based drinks. A cup of drip coffee would be definitely closer to 100.

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ProfessorPetrus t1_j1n7a8i wrote

Me and Boris Diaw just like to have an espresso before the game instead.

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bustedbuddha t1_j1nss93 wrote

Wait if they don't mean accuracy what do they mean?

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cantdecide23 t1_j1oz9rt wrote

They mean attack accuracy (when you jump up to spike the ball after the setter puts it up), in the last part of the title they are referring to accuracy during serves.

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TargaryenPenguin t1_j1pn5vr wrote

It's because they had only 12 players in the test which is a pathetically small sample making it very unlikely that anything would be significant except by chance. Unfortunately this makes the study a waste of time.

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Siggur-T t1_j1prk3r wrote

They should do this with games

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stevenconrad t1_j1qfsfy wrote

As a sport performance coach, I can believe this. The difference is likely improved reaction. Other actions (running, jumping, serving) are deliberate movements, but "attack accuracy" is very much a reactionary movement. Caffeine (in other studies) has been shown to improve reaction time; so having a slight advantage by anticipating or executing a movement a fraction of a second earlier could be measurable with a large enough sample.

This is pure speculation, though.

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[deleted] t1_j1n066j wrote

[deleted]

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ScipioLongstocking t1_j1noym3 wrote

>In most of the studies and real sports scenarios, caffeine is typically consumed 45–60 min before exercise in the form of capsules, coffee, or an energy drink. However, it can be problematic when fast caffeine absorption is desired. Interestingly, caffeinated chewing gum offers a faster method of delivery; after 5 min of chewing, even 85% of this supplement is bioavailable.

Since clicking the link and reading halfway through the introduction is too hard.

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