Competitive swimming places extraordinary demands on athletes, who often train twice daily and must fuel both explosive anaerobic efforts and prolonged aerobic work within tightly compressed recovery windows. Nutrition has emerged as one of the few performance levers directly under an athlete’s control, yet swim-specific guidance has historically lagged behind that developed for running and cycling. This narrative review synthesizes current evidence on nutritional interventions relevant to two interconnected outcomes in competitive swimmers: race performance and post-exercise muscular regeneration. Peer-reviewed studies, systematic reviews, meta-analyses, and position stands published between 2012 and 2025 were identified through PubMed, Scopus, and Google Scholar and synthesized narratively around macronutrient foundations (carbohydrate availability and nutrient-timed protein intake) and five well-evidenced ergogenic compoundscreatine monohydrate, beta-alanine, sodium bicarbonate, caffeine, and L-arginine/L-citrulline alongside two culturally accessible, food-based options of particular relevance to Indian swimmers, ashwagandha and beetroot. The evidence indicates that each intervention acts on a distinct physiological bottleneck, from phosphagen resynthesis and intramuscular buffering to central fatigue perception and vascular oxygen delivery, such that supplementation strategies are most effective when matched to event distance and training phase rather than applied uniformly. Important gaps remain, including small sample sizes, heterogeneous dosing protocols, and extrapolation from resistance-trained or mixed-endurance populations rather than swimmers themselves. Overall, the review supports a periodized, individualized approach to swim nutrition that layers macronutrient strategy with targeted, event-specific ergogenic support to optimize both performance and recovery across a demanding competitive season.