Boost your performance with L-citrulline

If you are looking to improve your physical performance, then this supplement is for you! L-citrulline is a naturally occurring amino acid in the body that has been extensively studied by science and has been shown to be effective in reducing muscle fatigue and improving endurance performance (Pérez-Guisado & Jakeman, 2010). But its potential doesn't stop there! Numerous studies suggest that this substance can also be beneficial for mental performance by optimizing cerebral oxygenation and promoting the balance of neurotransmitters, as well as for cardiovascular health (Figueroa et al., 2017).

What is L-Citrulline?

Its name comes from its discovery in the iconic summer fruit, the watermelon (Citrullus lanatus). This amino acid was first isolated in 1930 by Japanese researchers. Naturally produced by the body via the urea cycle, L-citrulline is a non-proteinogenic amino acid: it does not enter the composition of proteins but plays a crucial metabolic precursor role. It is notably the most effective precursor of plasma arginine, allowing sustained production of nitric oxide (NO), a powerful vasodilator (Schwedhelm et al., 2008).

Reduction of Muscle Fatigue and Improvement of Endurance Performance

The scientific literature demonstrates that citrulline supplementation before exercise reduces the perception of fatigue and improves total training volume in both strength and endurance training. These benefits are based on four major physiological levers:

1. Hemodynamics and Nitric Oxide: The conversion to NO increases muscle blood flow, facilitating the supply of nutrients and the efflux of acidic metabolites (Bailey et al., 2015).
2. Ammonia Buffering: During intense exercise, the accumulation of ammonia (neurotoxic and an inhibitor of glycolysis) promotes fatigue. Citrulline accelerates its elimination by converting it to urea, less toxic and easily excreted by the kidneys (Callis et al., 2012).
3. Optimization of Protein Synthesis: It indirectly stimulates the mTOR pathway, promoting tissue repair and glutamine synthesis (Jourdan et al., 2015).
4. ATP Resynthesis: It promotes aerobic energy production and the resynthesis of phosphocreatine after exercise, allowing for faster inter-set recovery (Bendahan et al., 2002).

Beyond sports, L-citrulline is a recognized clinical aid for improving endothelial function in hypertensive subjects and for supporting mild to moderate erectile function through a natural enzymatic pathway (Cormio et al., 2011).

Where can it be found?

It is present in certain cucurbitaceae, although dietary doses are often insufficient for a major ergogenic effect:

• Watermelons: ~150 mg / 100g
• Cucumbers and Melons: ~50 mg / 100g

For a therapeutic or sports effect, the use of isolated supplements or in the form of Citrulline Malate is recommended. Malate acts synergistically with citrulline to stimulate the Krebs cycle. Expert Protocol: Take 6g to 8g of Citrulline Malate (or 3g to 5g of pure L-Citrulline) approximately 60 minutes before exercise (Kerksick et al., 2018 - ISSN Stand).

In conclusion, L-citrulline is an essential amino acid to optimize metabolic performance and muscle pumps. By incorporating this ally into your routine, you maximize your anabolic potential while protecting your cardiovascular system.