Innovative Delivery Technologies and Pharmacokinetic Advancements in Caffeine Supplementation for Human Performance: A Narrative Review

Background and aim: For decades, caffeine has been considered a widespread and universally beneficial ergogenic aid. This perspective is reflected in guidelines and standardized dosage recommendations. However, contemporary evidence indicates that the traditional approach is not entirely effective in practice, and the effectiveness of caffeine supplementation may be influenced by factors such as age, gender, carrying specific allegles of genes responsible for caffeine metabolism, type of undertaken physical activity, or even the time of the day and the route of supplementation. This review aims to synthesize recent high-level evidence regarding these modifying factors. Description of the state of knowledge: Current data most often indicate that a safe dosage of caffeine falls within the range of 3–6 mg/kg of body weight. In the analyzed studies, this dosing regimen minimized the occurrence of bothersome side effects while consistently improving outcomes across mixed performance metrics. Specifically, caffeine enhances endurance, muscle strength - especially in the upper body when using free-weight loading - and the overall ability to undertake intermittent exercise, which is characteristic of team sports. Conclusion: While caffeine has an ergogenic effect in the majority of athletic scenarios, the modern approach, combining sports medicine and personalized medicine, does not focus on proving caffeine's baseline efficacy but on determining in which contexts its effects are most beneficial. Therefore, further exploration of this topic is required, taking into account the emerging individual variables.