Dive Summary:

• A small-scale U.S./Australian study, "The Effects of Caffeinated Energy Shots on Time Trial Performance," shows that Red Bull energy shots, as opposed to drinks, failed to improve experienced runners' time in a 5km run.
• The study claims to be the first to examine the effects of energy shot consumption on exercise performance, but the study's authors note that the administered caffeine dose (1.42-2.5 mg/kg of body mass) is lower than the possible threshold dose (>2.5 mg/kg of body mass) for caffeine to create a response.
• The study included five runners who were presented a placebo flavored like Red Bull, a Red Bull energy shot with 80mg of caffeine or a Guayaki Yerba Mate organic shot with 140mg of caffeine in a 59ml dose 60 minutes before each trial, and two of the runners were faster on the placebo, three were faster on Red Bull, and one was faster on Yerba Mate.
• Researchers admit the small sample size was one limitation and that more participants were needed to confirm the findings for "a variety of sport and field settings," but they concluded that ingestion didn't alter 5km treadmill time-trial performance compared to the placebo.

From the article:

Red Bull energy shots failed to improve the time in which experienced runners completed a 5km run versus a placebo, according to a new, but small-scale US/Australian study claiming to be the first to examine the efficacy of shots rather than energy drinks on exercise performance. ...