Caffeine’s arguably the most studied ergogenic around with loads of studies showing it reduces the rate of perceived exertion; i.e. it makes exercise easier.
Carbs are the primary fuel supply for high-intensity physical activity. However, as your brain burns 100-150g glucose daily, fail to carb up and you’ll find training mentally tougher and less productive.
Creatine’s associated with instant energy for power efforts, but there’s also evidence that it improves cognitive function. In a tri, that means a better pacing strategy.
These potent antioxidants, found in cocoa powder, increase cerebral bloodflow. Like creatine, it’s suggested that this results in improved cognitive function and more reliable decision making.
Guarana is a rich source of not only caffeine but antioxidants, too. Research has revealed its fatigue-lowering benefits plus improved cognitive performance.