Personer med avsikt att använda tillskott faller lättare för placebo

[King Grub]

Purpose:

We investigated associations between athletes’ use of sport supplements and their responsiveness to placebo and nocebo interventions.

Methods:

Participants (n = 627) reported their intention to use, and actual use of, sport supplements. They then completed a 5 × 20 m repeat sprint protocol in the baseline condition, before being randomized to one of three treatments. Participants in the positive-belief treatment were administered an inert capsule described as a potent supplement which would improve sprint performance. Participants in the negative-belief treatment were administered an inert capsule described as a potent supplement which would negatively affect sprint performance. Participants in the control treatment received neither instruction nor capsule. Twenty minutes after baseline trials, all participants completed the same repeat sprint protocol in the experimental condition.

Results:

Compared with controls, no mean differences in performance were observed between baseline and experimental conditions for the positive-belief treatment (−0.07% ± 0.27%, d = 0.02), but mean differences were observed for the negative-belief treatment (−0.92% ± 0.31%, d = 0.32), suggesting a moderate nocebo effect. In the positive-belief treatment, however, a relationship between intention to use supplements and performance was observed. Performance worsened by −1.10% ± 0.30% compared with baseline for participants not intending to use supplements, worsened by −0.64% ± 0.43% among those undecided about supplement use, but improved by 0.19% ± 0.24% among those participants intending to use supplements.

Conclusions:

Information about a harmful supplement worsened repeat sprint performance (a mean nocebo effect), whereas information about a beneficial supplement did not improve performance (no mean placebo effect was observed). However, participants' intention to use sport supplements influenced the direction and magnitude of subsequent placebo responses, with participants intending to use supplements more likely to respond to the positive intervention.

Athletes Intending to Use Sports Supplements Are More Likely to Respond to a Placebo. Medicine & Science in Sports & Exercise: September 2017 - Volume 49 - Issue 9 - p 1877–1883.

[smerk]

OT kanske men hur stora muskelökningar har man sett som högst av placebo jämfört med en kontrollgrupp?

[Max]

Ursprungligen postat av smerk

OT kanske men hur stora muskelökningar har man sett som högst av placebo jämfört med en kontrollgrupp?

Muskelökningar? Vad jag kan se från abstraktet så har man undersökt sprint-prestation. Eller undrar du över någon annan/andra studier som undersökt detta?

[Bruce Banner]

Ursprungligen postat av smerk

OT kanske men hur stora muskelökningar har man sett som högst av placebo jämfört med en kontrollgrupp?

En klassisk studie på placeboeffekt när deltagarna trodde de fick Dianabol visar på dramatiska styrkeökningar (inte muskelvolym osv). Så en viss effekt kan man härleda till placebo.

http://www.arielnet.com/articles/sho...ts-of-placebos

MVH
/Bruce