Fuel-90: validation of a questionnaire to assess players’ knowledge of carbohydrate guidelines for soccer

Abstract Purpose Professional soccer players typically under-consume carbohydrate in relation to contemporary guidelines, where their dietary behaviors may, in part, be underpinned by lack of knowledge. Accordingly, we aimed to develop and validate a novel and time-efficient questionnaire for use with professional soccer players to assess soccer players’ knowledge of the current carbohydrate guidelines. Method The Fuel-90 questionnaire was developed by research-active practitioners, based upon the 2021 Union of European Football Associations (UEFA) expert group statement on nutrition in elite soccer. The Fuel-90 questionnaire comprised 25 multiple choice questions divided into 5 sub-sections, assessing: (1) Fueling Fundamentals, (2) Match Day-1, (3) Pre-match Meal, (4) In-match fueling and (5) Post-match Recovery. The questionnaire was administered to 62 professionally Sport and Exercise Nutrition registered practitioners (SENR), 186 professional male adult soccer players from the English Premier League and Championship (PRO) and 145 recreational male adult soccer players (REC) ( n = 393). Of the 186 professional soccer players, 31 completed a second questionnaire within 21 days of their first completion. Results: Construct validity was confirmed by significant differences in Fuel-90 score between the three groups (SENR: 24 ± 2; 96 ± 6% > PRO: 15 ± 4; 59 ± 17% > REC 13 ± 4; 51 ± 14%; ( p < 0.005). Fuel-90 demonstrated acceptable internal consistency (Cronbach’s alpha = 0⋅86). Fuel-90 questionnaire was established (r = 0.74; p < 0.001), with no significant learning effect between test (17 ± 4) and re-test (18 ± 4; p = 0.295). Conclusion The Fuel-90 questionnaire presents a valid, reliable, and practical tool for practitioners to assess professional soccer players’ knowledge of current carbohydrate guidelines, thereby providing an initial framework to tailor subsequent education and nutrition interventions.