The Most Important Amino Acid To Flip The Growth Switch

The Most Important Amino Acid To Flip The Growth Switch

Leucine turns on protein synthesis, which stimulates muscle hypertrophy. An amino acid that is regularly taken as a supplement, leucine is essential to the body.  The body needs it to survive, yet it can't produce it.  Hence, leucine must be provided through food intake or supplements.

Leucine is a branched chain amino acid (BCAA). The other two BCAAs are valine and isoleucine, with leucine the most promising of the three when used as a body building supplement.

“Leucine Is An Amino Acid That Is Used By The Body Mainly For Building Muscle And Providing Energy. It’s Widely Used To Improve Strength During Exercise And Muscle Recovery Times”

Top Benefits Of Leucine Consumption

1.  Used To Increase Energy Production

2.  Improves Muscles & Helps Prevent Muscle Fatigue & Soreness

3.  Increases The Amount Of Protein, Enhancing Protein Synthesis

4.  May Increase Strength, Proven To Assist In Heavier Weight Lifts

5.  May Increase Longevity By 30 To 50%

6.  Reduces The Risk Of Hardening Of The Arteries (Atherosclerosis)

7.  May Reduce Obesity By 25%



"SSP Loads All Three Of Its Products In The SYSTEM With 2.5g Of Leucine.  That Is A Total Of 7.5g Of Leucine When You Combine The PRE Workout Formula, POST Workout Formula & Lean Muscle Meal Formula!"   


  • Leucine, isoleucine, and valine are the three branched-chain amino acids (BCAAs) that are highly effective for stimulating skeletal muscle protein synthesis. Interestingly, leucine has much greater power on stimulating protein synthesis compared to any other amino acid.
  • Declining leucine levels signal mTOR that there's a lack of dietary protein present to synthesize new skeletal muscle protein, therefore disabling mTOR. Upon ingesting increased concentrations of leucine, the elevated amino acid then signals mTOR that sufficient dietary protein exists, and switches on overall protein synthesis. An important point to remember is an increase in mTOR activity (and all aspects of the pathway with which it belongs) results in an increase in protein-building and more growth!


  • Leucine, isoleucine and valine (BCAA), make up about one-third of muscle protein. Of these, leucine has been the most thoroughly investigated because its oxidation rate is higher than that of isoleucine or valine. Leucine also stimulates protein synthesis in muscle and is closely associated with the release of gluconeogenic precursors, such as alanine, from muscle.
  • Significant decreases in plasma or serum levels of leucine occur following aerobic (11 to 33%), anaerobic lactic (5 to 8%) and strength exercise (30%) sessions. In skeletal muscle, there is a decrease in leucine level and a reduction in glycogen stores during exhaustive aerobic exercise.
  • Consumption of BCAA (30 to 35% leucine) before or during endurance exercise may prevent or decrease the net rate of protein degradation, may improve both mental and physical performance and may have a sparing effect on muscle glycogen degradation and depletion of muscle glycogen stores.
  • Studies show supplementation of leucine undertaking intensive resistance training exercise resulted in an increased deposition of fat-free mass and an accompanying increase in strength. Muscle proteolysis was also decreased with HMB, accompanied by lower plasma levels of enzymes indicating muscle damage and an average 50% decrease in plasma essential amino acid levels.
  • BCAA supplementation (76% leucine) in combination with moderate energy restriction has been shown to induce significant and preferential losses of visceral adipose tissue and to allow maintenance of a high level of performance.

Young Athletes: when leucine was provided, significant increases in blood levels of amino acids occurred very rapidly. In fact, within 15 minutes of ingesting leucine, blood levels of the essential amino acids began to rise rapidly, and within 30 minutes of ingestion they reached their peak levels. In addition, rates of muscle protein synthesis reached similar peak levels regardless of whether the solution contained 26 or 41 percent leucine.

Older Athletes: studies show an increase in protein synthesis with a 41 percent solution. This should come as no surprise, though, as previous research has demonstrated reduced muscle protein synthesis in older individuals when only small amounts of essential amino acids are ingested. Due to a possible decrease in sensitively to leucine, individuals 65  years and older should aim to consume extra leucine to activate muscle protein synthesis.

Blog Sources:

Back to blog

Contact form