L‑citrulline is a non‑essential amino acid found in high amounts in watermelon, cucumbers, and other melons. Over the past 15 years, researchers have shown that supplementing with L‑citrulline can boost performance in both endurance activities (like running or cycling) and short, intense efforts (like weight lifting or sprinting). In today’s sports‑nutrition market, it’s most often delivered as citrulline malate—a 2:1 blend of L‑citrulline and malic acid—to take advantage of both ingredients at once.
Once ingested, L‑citrulline raises blood levels of arginine, which in turn fuels nitric‑oxide production and widens blood vessels. That improved circulation delivers more oxygen and nutrients to working muscles, delaying fatigue. Meanwhile, malate (the salt of malic acid) enters muscle cells and feeds directly into the tricarboxylic‑acid (TCA) cycle—the body’s primary energy‑making pathway. By keeping the TCA cycle running smoothly, malate helps your cells make ATP more efficiently and prevents pyruvate from piling up as lactic acid, so you experience less “burn” and recover faster between bursts.
Together, the two work hand in hand: citrulline widens and primes your delivery system, and malate keeps your cellular engines revving at peak output. The result is better muscle perfusion, steadier energy production, and a noticeable boost in both aerobic endurance and anaerobic power—exactly why citrulline malate remains a staple in the most effective pre‑workout formulas.
