Choose the SiS GO + Caffeine Gel for a fast physical and mental boost, when you need that racing edge. When pushing yourself hard, your brain controls how fatigued you feel. Caffeine has been repeatedly shown to improve performance by lowering your perception of effort by providing a boost just when you need it. Research suggests that 5 mg of caffeine per kg of body mass is thought to be beneficial for endurance performance, which for a 70kg person would equal 350mg. SIS GO Energy + Caffeine Gel 150mg can help you hit this goal.