Neuromodulation technologies like transcranial direct current stimulation (tDCS) might enable professional and amateur athletes to reach their respective levels of physical excellence in a safe, cost-effective, and fair manner. Key factors that may assist an athlete in achieving their potential usually include training for many years, often since childhood, and access to a high level of funding. If cost-effective neuromodulation based on tDCS lives up to its promises (regarding safety and efficacy), tDCS can help athletes to learn relevant skills more effectively and thus reach their respective levels of physical excellence more quickly, especially athletes with limited time and resources. Whilst dangerous, illegal drugs such as EPO and steroids can increase performance without training, current evidence suggests that tDCS assists an athlete in improving their performance in combination with training. Given that the World Anti-Doping Association has not made any statement regarding the permissibility of tDCS, whilst access to and popularity of tDCS are constantly increasing, it is important to consider more in-depth if the use of tDCS can be justified. Here, we will outline three key criteria that any performance-enhancing measure must meet if its use can be considered ethical and permissible according to WADA requirements. tDCS must meet our requirements of safety, hard work from the athlete and accessibility. The preliminary evidence regarding its safety, its relatively low cost and the reasonable expectation, that long-term improvements can only be made if its application is paralleled by intense training, justifies its further research in the context of athletic performance enhancement. Moreover, we also consider its potential wider impact, especially how tDCS could help to level the playing field between amateur and elite athletes.