“In controlled exercise settings the placebo response…..Wright et al. (2009) found that runners’ performance increased by 6.5%, and that slower runners showed a stronger placebo effect after ingesting purported nutritional ergogenic aids.”

“…..the placebo effect of caffeine on resistance exercise to failure was studied with 12 men (Duncan, Lyons, & Hankey, 2009). Performance was better when participants expected that they have ingested caffeine.”

“Another study of 12 men, drinking either plain water (control), or a labeled performance enhancer drink (placebo), or fatigue inducing (nocebo) drink, showed a modest placebo effect in peak minute power incremental arm crank exercise (Bottoms, Buscombe, & Nicholettos, 2014).”

A.Szabo, et al
Laboratory Investigation of Specific and Placebo Effects of a Magnetic Bracelet on a Short Bout of Aerobic Exercise
Journal Of Sport Behavior – December 2017