|Pre-workout drinks were yesterday, the modern athlete snorts his ergogenics.|
In their latest study, Kevin De Pauw, et al. investigate whether this effect would translate to real-world increases in exercise and/or cognitive performance (reaction times).
For their study, the scientists recruited eleven non-smoking and moderately trained male subjects (age: 22±2 yrs) with a low daily caffeine consumption (23 ± 27 mg/day). All subjects were asked to maintain the same nutrition pattern before each experimental trial. The latter included a 30 s Wingate test and a 30 min time-trial (TT) performance test interspersed by 15 min of rest.
"The three experimental trials that were identical except for the NAS solution. Each trial started at the same time of the day and included two exercise performances, i.e. the 30 s Wingate test and a 30 min TT performance, always performed in the same order and separated by 15 min of passive rest. During the exercise performances no verbal encouragement or other motivational measures were provided" (De Pauw. 2017).Before they started to cycle, the subjects used a nasal spray that contained solutions with caffeine (CAF), glucose (GLUC) or placebo (PLAC) in randomized, double-blind, placebo-controlled, cross-over manner. The solutions were nasally administered with a standard insufflator and were prepared by an independent company an here's what was in the sprays:
- all nasal sprays contained 400 mL water, 40 mg benzalkoniumchloride as a preservative plus natrium chloride as a base, as well as hydroxypropyl methylcellulose (HPMC) and mannitol to modify the particle morphology and flowability
- the caffeine spray (CAF) and glucose sprays (GLUC) contained a final concentration of 16mg/ml and 80mg/ml caffeine and glucose, respectively
|Figure 1: Graphical overview of the study design (De Pauw. 2017).|
What about the increases in cognitive performance? In contrast to what De Pauw et al. had hoped for, their reaction time test did not show a statistically significant benefit of either of the treatments. This does not mean that other parameters in the cognitive domain couldn't benefit from snorting glucose or caffeine, though. Thus, it would be interesting to see future studies investigate the effects on memory performance and co.Performance increases that reached statistical significance only in the glucose, yet not in the caffeine group, where the 1.2% and 0.5% increase in power output during the Wingate test and time trial in the caffeine group did not achieve statistical significance. The average increase in power output during the time-trial in the glucose group, on the other hand, was statistically significant.
|Figure 2: Peak power and average power in watt, relative change compared to placebo trial in % (De Pauw. 2017).|
- Chambers, E. S., M. W. Bridge, and D. A. Jones. "Carbohydrate sensing in the human mouth: effects on exercise performance and brain activity." The Journal of physiology 587.8 (2009): 1779-1794.
- De Pauw, Kevin, et al. "Do Glucose and Caffeine Nasal Sprays Influence Exercise and/or Cognitive Performance?." International Journal of Sports Physiology and Performance (2017): 1-22.
- Doering, Thomas M., et al. "The effect of a caffeinated mouth-rinse on endurance cycling time-trial performance." International journal of sport nutrition and exercise metabolism 24.1 (2014): 90-97.
- Phillips, Shaun M., et al. "The Influence of Serial Carbohydrate Mouth Rinsing on Power Output during a Cycle Sprint." Journal of sports science & medicine 13.2 (2014): 252.