Emerging evidence suggests that the presence of oxidative stress per se does not rationalize the use of antioxidants, emphasizing the need to identify "responsive" phenotypes for personalized interventions¹. This originates, most probably, from the fact that we all inherit and acquire different and/or unique biological and behavioural characteristics. These characteristics regulate the impact of any (e.g., nutritional) treatment that affects physiology resulting in beneficial, harmful or neutral outcomes (e.g., exercise performance)^2,3. As a result, the issue of individual responsiveness attracted the interest of researchers across diverse scientific fields, while personalized nutrition became a central translational goal. Unfortunately, most studies on the topic followed suboptimal methodological approaches to quantify individual responses and to specify statistical thresholds of effectiveness (‘minimal clinically important difference’ or ‘smallest worthwhile change’)^4,5. Thus, the typical classification of participants after any treatment into “high”, “low” or “adverse” responders commonly lied in the eye of the beholder. Herein, diverse methodological and statistical practices that seem to provide a more straightforward approach for personalized sports nutrition studies will be presented, which may be of interest for research and applied purposes.