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.
stevenconrad t1_j1qfsfy wrote
Reply to A study on volleyball players found that caffeinated chewing gum significantly improved attack accuracy compared to placebo. However, this did not improve results in jumping tests, running tests, and other volleyball specific-skills, including speed tests and accuracy during the volleyball serve by glawgii
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.