Creatine monohydrate remains the most extensively studied and effective performance supplement, with over 1000 studies confirming its safety in healthy individuals. Endogenous synthesis from arginine, glycine, and methionine produces approximately 1 to 2 g daily, while the body's total creatine pool of 120 to 140 g is stored as phosphocreatine primarily in skeletal muscle. During high-intensity exercise, phosphocreatine donates a phosphate group to ADP via creatine kinase to rapidly regenerate ATP, supporting the first 10 to 15 seconds of maximal effort. Standard supplementation protocols involve an optional loading phase of 20 g/day for 5 to 7 days followed by 3 to 5 g/day maintenance, or simply 3 to 5 g/day without loading (which saturates muscle stores in 3 to 4 weeks). Creatine increases strength and power output by 5 to 15%, supports lean mass gains, enhances recovery between sets, and provides cognitive benefits particularly for vegetarians, the sleep-deprived, and those recovering from traumatic brain injury.
Beta-alanine and sodium bicarbonate work through complementary buffering mechanisms to delay exercise-induced acidosis. Beta-alanine is the rate-limiting precursor for carnosine synthesis in muscle, and chronic supplementation at 3.2 to 6.4 g/day increases muscle carnosine by 40 to 80% over 4 to 12 weeks. Carnosine's imidazole ring (pKa ~6.83) is ideally positioned to buffer the hydrogen ions that accumulate during glycolytic exercise, accounting for 10 to 20% of muscle buffering capacity and most effective for efforts lasting 60 seconds to 4 minutes. The harmless paresthesia (tingling) that accompanies beta-alanine is caused by activation of MrgprD receptors on sensory neurons and can be managed by dividing doses below 1.6 g or using sustained-release formulations. Sodium bicarbonate (0.3 g/kg body weight taken 60 to 90 minutes pre-exercise) provides extracellular buffering and is most effective for efforts of 1 to 7 minutes, though 30 to 50% of users experience gastrointestinal distress that can be mitigated by splitting the dose or using sodium citrate as a gentler alternative.
Nitric oxide enhancement through dietary nitrate and amino acid precursors represents a third major pathway for performance support. Beetroot juice containing 6 to 12 mmol nitrate (400 to 800 mg) increases nitric oxide bioavailability via the nitrate-nitrite-NO pathway, which becomes increasingly important with age as endothelial NOS function declines. This pathway requires oral bacteria to reduce nitrate to nitrite (meaning mouthwash use abolishes the benefit) and works synergistically with citrulline, which raises plasma arginine more effectively than arginine supplementation itself by bypassing intestinal and hepatic first-pass metabolism. Citrulline malate at 6 to 8 g has been shown to increase repetitions to failure by 10 to 53% in resistance training while reducing ammonia accumulation and perceived exertion. HMB (beta-hydroxy beta-methylbutyrate), a leucine metabolite, works primarily as an anti-catabolic agent by inhibiting the ubiquitin-proteasome pathway, with its strongest evidence in preventing muscle loss during caloric restriction, bed rest, and aging rather than promoting gains in already-trained athletes.
Recovery from intense training benefits from targeted nutritional support. Hydrolyzed collagen peptides (10 to 20 g daily) provide glycine (33%), proline (13%), and hydroxyproline (11%), which are limiting amino acids in typical Western diets and serve as building blocks for connective tissue. A specific protocol of 15 g collagen or gelatin with 50 mg vitamin C taken 30 to 60 minutes before exercise doubles collagen synthesis in tendons (Shaw et al. 2017), making this a foundational strategy for injury prevention. Tart cherry juice concentrate reduces delayed-onset muscle soreness through its anthocyanin content and anti-inflammatory effects. Omega-3 fatty acids (2 to 3 g EPA+DHA daily) resolve inflammation through specialized pro-resolving mediators (resolvins, protectins, maresins) without the blunting of training adaptations that excessive antioxidant supplementation can cause. Caffeine, the most widely consumed ergogenic aid, works primarily through adenosine receptor antagonism at doses of 3 to 6 mg/kg taken 30 to 60 minutes pre-exercise, improving endurance, strength, and power by 2 to 5%, with L-theanine (200 mg) providing synergistic focus without jitteriness.