Yes, you should drink water before running, as being appropriately hydrated contributes to optimal health and exercise performance. Before running, athletes can achieve euhydration by consuming a fluid volume equivalent to 5-10 mL/kg BW (2-4 mL/lb) in the 2-4 hours before exercise [2]. Fluid deficits of over 2% of a runner’s body weight may compromise performance and cognitive functioning. Therefore it is important to stay hydrated before, during and after your run, especially in hot and humid conditions [1, 2]. Not taking in enough water and electrolytes can lead to dehydration, which can make exercise more difficult, increase fatigue, increase heart rate, cause electrolyte imbalances and difficulties regulating body temperature [3, 4].