“…Energy gels with a 0.5% menthol concentration, as determined from and described in a previous investigation [24], were produced by a commercial sports nutrition manufacturer (GU Energy Labs, Berkeley, CA, USA) using the following ingredients: maltodextrin, water, fructose, L-leucine, sodium citrate, medium-chain triglycerides, sea salt, potassium citrate, citric acid, calcium carbonate, L-valine, gellan gum, L-isoleucine, sodium benzoate (preservative), potassium sorbate (preservative), natural L-menthol (Sigma-Aldrich, St. Louis, MO, USA), and natural citrus flavor. A placebo gel was also produced containing a natural mint flavor in place of the l-menthol (Virginia Dare, Brooklyn, NY, USA), as previously described [23].…”