Soccer

The aim of this research is to determine whether sodium citrate supplementation, taken at the best individual time, would improve repeated sprint performance in professional female soccer players. The main questions it aims to answer are: 1. Does sodium citrate improve sprint times, peak power, minimum power, and mean power during repeated sprints? 2. Does sodium citrate lower fatigue index (the drop in power across sprints) during repeated sprint exercise? 3. Does sodium citrate change blood bicarbonate, pH, and lactate levels before and after exercise? 4. Does sodium citrate affect how hard exercise feels (perceived exertion)?

This randomized crossover study compared the acute post-activation performance responses to isometric and dynamic squat-based preconditioning protocols performed with and without electromyostimulation (EMS). Participants completed five randomized experimental conditions: maximal voluntary isometric contraction (MVIC), dynamic contraction (DC), MVIC+EMS, DC+EMS, and EMS only (O-EMS). Baseline and post-intervention assessments included countermovement jump (CMJ), countermovement jump with arm swing (CMJWH), zig-zag agility, and shooting speed, with post-tests conducted after a 4-minute recovery period. Perceptual responses, including ratings of perceived exertion (RPE), perceived discomfort (RPD), and fatigue (VAS), were recorded immediately after each protocol. All sessions were conducted between 14:00 and 16:00 under standardized conditions, with protocol order randomized and participants instructed to avoid strenuous exercise and food intake before testing.