Grant, N., Turner, C. E., Stinear, C. M., & Byblow, W. D. (2012). Immediate energy signaling during physical activity. Presentation 2332 at the 59th Annual Meeting of the American College of Sports Medicine, San Francisco, California; May 29-June 2, 2012.

"The presence of carbohydrate in the mouth has been associated with immediate improvements in human performance and the facilitation of neural drive to muscle. Oral energy receptors may be involved in a novel form of sensorimotor integration, capable of regulating motor output during exercise."

This study used neuroimaging to examine central influences of oral carbohydrate during a motor task, identifying areas of the brain involved in immediate energy signaling. Carbohydrate and placebo solutions with identical perceptual qualities but variable energy content were infused and recovered from the mouth in a double-blind, counterbalanced design. Functional Magnetic Resonance Imaging was used to measure blood oxygen level-dependent contrast in the brain whilst Ss generated isometric force during a handgrip task.

Carbohydrate in the mouth increased the motor cortex activation network when compared to placebo during the handgrip task. Carbohydrate activated additional areas in the left insular cortex and left central operculum (primary taste areas), and regions of the frontal cortex associated with rewarding sensory stimuli.

Implication. Oral carbohydrate enhanced the extent of a neural activation network and improved performance during a motor task. The increased activity within motor cortex and regions involved in reward processing provides a neural basis for enhancements in force production and motor output observed with oral exposure to carbohydrate.

[Editor's note: This study suggests that swirling carbohydrate in the mouth (e.g., glucose candies) in the minute before starting a high-intensity performance, such as a swimming race or pitching a baseball, will enhance the performance that follows. It could be a valuable part of the last phase of a warm-up routine.]

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