Effects of consuming coffee on empty stomachs and physical performance

Consuming coffee on an empty stomach may not cause direct damage to the stomach lining due to its protective mucus layer, but it can increase gastric acid production. This increase in acidity can lead to heartburn or exacerbate conditions such as gastritis and esophagitis. Additionally, caffeine can relax the esophageal sphincter, potentially causing gastroesophageal reflux.

Regarding physical activity, caffeine acts as a stimulant on the central nervous system by blocking adenosine receptors, which reduces the perception of effort. However, it does not serve as metabolic fuel. While caffeine may mask fatigue during short workouts of less than 45 minutes, it cannot replace carbohydrates for longer sessions. In endurance activities lasting over an hour, relying solely on caffeine without carbohydrate intake can lead to a sudden energy crash once glycogen stores are depleted.

Individual responses to caffeine vary, with potential side effects including digestive discomfort, muscle tremors, nervousness, and increased heart rate.