Does Leucine Trigger Muscle Growth?

Written by Dr. Steve Chaney on . Posted in Exercise, Issues, Supplements and Health

What Does The Perfect Post-Workout Protein Shake Look Like?

Author: Dr. Stephen Chaney

 Post-Workout Protein ShakeIf you work out on a regular basis and read any of the “muscle magazines”, you’ve seen the ads. “Explode Your Muscles.” “Double Your Gains.” They all claim to have the perfect post-workout protein shake, backed by science. They all sound so tempting, but you know that some of them have to be scams.

I told you about some of the sports supplements to avoid in a previous “Health Tips From the Professor”. In this issue, I’m going to ask “What does the perfect post-workout protein shake look like?”

For years athletes have been using protein beverages containing branched chain amino acids after their workouts to maximize muscle gain and recovery. There was some science behind that practice, but the major questions were unanswered. Nobody really knew:

  • How much protein is optimal?
  • What kind of protein is optimal?
  • What amount of branched chain amino acids is optimal?
  • Are some branched chain amino acids more important than others?
  • Does the optimal amount of branched chain amino acids depend on the amount of protein?

As a consequence, after workout protein supplements were all over the map in terms of protein source, protein amount, branched amino acid amount and type of branched chain amino acids. Fortunately, recent research has clarified many of these questions.

How Much And What Kind Of Protein Do You Need?

  • Recent research has shown that the optimal protein intake for maximizing muscle gain post workout is 15-20 gm for young adults (Katsanos et al, Am J Clin Nutr 82: 1065-1073, 2005; Moore et al, Am J Clin Nutr, 89: 161-168, 2009) and 20-25 gm for older adults (Symons et al, Am J Clin Nutr 86: 451-456, 2007).
  • More protein isn’t necessarily better. The effect of protein intake on post workout muscle gain maxes out at around 25 gm for young adults and 30 gm for older adults (Symons et al, J Am Diet Assoc 109: 1582-1586, 2009).
  • Whey protein is the best choice for enhancing muscle gain immediately after a workout. Other protein sources (soy, casein, chicken) are better choices for sustaining muscle gain over the next few hours.

Does Leucine Trigger Muscle Growth?

  • It turns out that leucine is the only branched chain amino acid that actually stimulates muscle protein synthesis (Am J Physiol Endocrinol Metab 291: E381-E387, 2006). And protein is what gives muscles their strength and their bulk.
  • Recent research has shown that 2-3 gm of leucine (2 gm for young adults; 3 gm for older adults) is sufficient to maximize post workout muscle gain if protein levels are adequate (Am J Physiol Endocrinol Metab 291: E381-E387, 2006).

Unanswered Questions About Optimizing Muscle Gain Post-Workout

  •  Do the other branched chain amino acids play a supporting role, or is leucine alone sufficient to drive post-workout muscle gain?
  • Can leucine still help maximize post-workout muscle gain if protein intake is inadequate? If so, how much leucine is needed?

Does Leucine Enhancement Improve Low Protein Shakes?

Lrg Extension ExercisesA recent study (Churchward-Venne et al, Am J Clin Nutr, 99: 276-286, 2014) seems to answer those two questions. The authors compared the effect of 5 protein-amino acid combinations on muscle protein synthesis in 40 young men (~21 years old) following unilateral knee-extensor resistance exercise. The protein shakes contained:

  • 25 gm of whey protein, which naturally contains 3 gm of leucine (high protein)
  • 6.25 gm of whey protein, which naturally contains 0.76 gm of leucine (low protein)
  • 6.25 gm of whey protein with 3 gm of leucine (low protein, low leucine)
  • 6.25 gm of whey protein with 5 gm of leucine (low protein, high leucine)
  • 6.25 gm of whey protein with 5 gm of leucine + added isoleucine and valine (the other branched chain amino acids). (low protein, branched chain amino acids).

The results were clear cut:

  • The high protein shake (25 gm of protein) was far superior to the low protein shake (6.25 gm of protein) at enhancing post workout protein synthesis. This is consistent with numerous other published clinical reports.
  • Adding 3 gm of leucine to the low protein shake had no effect on post-workout protein synthesis, but 5 gm of added leucine made the low protein shake just as effective as the high protein shake at supporting post-workout protein synthesis.

In short, leucine can improve the effectiveness of a low protein shake, but you need more leucine than if you chose the high protein shake to begin with.

  • Adding extra branched chain amino acids actually suppressed the effectiveness of leucine at enhancing post-workout protein synthesis. These data suggest:
    • Leucine probably is the major amino acid responsible for the muscle gain reported in many of the previous studies with branched chain amino acids.
    • If the other branched chain amino acids play a supporting role in the muscle gain, the quantities that occur naturally in the protein are probably enough. Adding more may actually reduce the effectiveness of leucine at stimulating muscle gain.

While this is a single study, it is consist with numerous other recent clinical studies. It simply helps clarify whether leucine can increase the effectiveness of a low protein supplement. It also clarifies the role of branched chain amino acids.

Also, while this study focused on protein synthesis, numerous other studies have shown that optimizing post-workout protein and leucine intake results in greater muscle gain (for example, Westcott et al., Fitness Management, May 2008)

The Bottom Line

Research on post-workout nutrition to optimize muscle gain from the workouts has come a long way in recent years. It is now actually possible to make rational choices about the best protein supplements and foods to support your workouts.

  • If you are a young adult (17-30), you should aim for 15-20 gm of protein and about 2 gm of leucine after your workout.
  • If you are an older adult (50+), you should aim for 20-25 gm of protein and 3 gm of leucine after your workout.
  • If you are in between you are on your own. Studies haven’t yet been done in your age group, but it’s reasonable to assume that you should aim for somewhere between the extremes.
  • If you are getting the recommended amounts of whey protein, the leucine level will also be optimal. If you are using other protein sources you may want to choose ones with added leucine.
  • The research cited above shows that you can make a low protein supplement effective by adding lots of leucine, but that’s going to require artificial flavors and sweeteners to cover up the taste of that much leucine. I would recommend choosing one that provided adequate protein to begin with.
  • While the research in this area is still somewhat fluid, I would avoid protein supplements with added branched chain amino acids other than leucine. If the paper I cited above is correct you probably get all of the other branched chain amino acids you need from your protein and adding more may actually interfere with the effect of leucine on muscle gain.
  • I’d pretty much forget all the other “magic ingredients” in post-workout supplements. If you’re a novice there is some evidence that arginine and HMB may be of benefit, but if you have been working out for more than 6 months, the evidence is mixed at best. As for the rest, the clinical studies are all over the map. There’s no convincing evidence that they work.
  • Whey protein is the best choice for enhancing muscle gain immediately after your workout. Soy and casein are better choices for sustaining muscle gain over the next few hours. If you’re looking at meat protein, chicken is a particularly good choice. Four ounces of chicken will provide the protein and leucine you need to sustain muscle gain for several hours.
  • Even if you are not working out, recent research on dietary protein and leucine has important implications for your health. In a recent “Health Tips From the Professor” I shared research showing that optimizing protein and leucine intake helps to increase muscle retention and maximize fat loss when you are losing weight.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

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Comments (8)

  • Mikell Fuhrmann

    |

    Hi I am confused but I just listened to the State of the Union speech & I’m
    old. I have taken ESP Shaklee protein for 20 yrs. not over weight, exercise off/on still have biceps but wrinkles on my upper arms. Is this just
    another part of aging? I am 76 yo. Like your tips. Thanks

    Reply

    • Dr. Steve Chaney

      |

      Dear Mikell,
      At 76 biceps are good. The wrinkles are more likely due to sun exposure and age than to protein deficiency.
      Dr. Chaney

      Reply

  • Pam McDonald

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    Great article. Correct me if I’m wrong, but why doesn’t Shaklee’s Physique include leucine in their ingredients? Thanks

    Reply

    • Dr. Steve Chaney

      |

      Dear Pam,
      If I had my way every company would list the amino acid composition of their products. However, it is not required. And whey protein is considered a complete protein, so amino acid composition information may not be necessary. As I said in my article, whey protein supplements that provide enough protein generally provide enough leucine as well.
      Dr. Chaney

      Reply

  • nick

    |

    Well done. Although I agree with most of your post, I disagree on the added BCAA’s having a negative impact on the Leucine Trigger. Yes some research suggest otherwise, but most good studies do not. That being said, All whey proteins are not the same. We know from the human genome project and subsequent human proteome project that “quality’ of protein, and in this case Whey, has a tremendous impact on genomic response. Most mass produced whey comes from inferior or lesser quality bovine–CAFO raised. Over 80% of the market carries this inferior whey. Most are also denatured, where the bonds are broken between the amino acid link thus distorting that proteins unique finger print or key like structure, if you will. Proteins are the environmental signal for genes to encode or make the 350k or so proteins that make up all the tissues of our body. If you denature the Whey, as with most Mass market Whey, it can’t unlock the genes encoding potentiality. Then you have to consider all the supporting cast necessary for the highest absorption and utilization possibility, such as: Prebiotic’s, Probiotics, enzymes, minerals and trace minerals. The particular transport system in the gut requires this combination in fairly exact quantities.

    Reply

    • Dr. Steve Chaney

      |

      Dear Nick,

      I agree that it is premature to declare that BCAA’S have a negative effect on the leucine trigger based on a single study. However, it is pretty clear from multiple studies at this point that most of the benefits attributed to BCAA’s in general are due to leucine alone. We need adequate amounts of the other BCAA’s, but it is not clear that we gain any extra benefit from higher levels of any BCAA except leucine.

      The rest of your argument is misguided. It appears to be based on the assumption that proteins can be absorbed from the intestine intact. In fact, all proteins need to be broken down to individual amino acids to be absorbed by the intestine. When that does not occur and proteins or portions of proteins are absorbed into the bloodstream intact, such as in “leaky gut” syndrome, they are recognized as foreign antigens by our immune system and can trigger inflammation and a number of serious diseases.

      Dr. Chaney

      Reply

  • Jay Goodman

    |

    Dr Chaney, it was awesome to meet you this last weekend! So can you provide any updated studies on Leucine? I would love to read it!

    Reply

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Latest Article

Relieve Hip Pain After Sitting or Driving

Posted June 20, 2017 by Dr. Steve Chaney

Relief is Just a Few Movements Away!

Author: Julie Donnelly, LMT – The Pain Relief Expert

Editor: Dr. Steve Chaney

 

relieve hip pain after sittingI’m on a long business trip, speaking and teaching in Tennessee and New York, and the drive from Sarasota, FL meant many hours of driving over several days.  One of my stops was to visit with Suzanne and Dr. Steve Chaney at their home in North Carolina.  It was that long drive that became the inspiration for this blog.

After all those hours of driving, my hip was really sore. It was painful to stand up. While talking to Suzanne and Dr. Chaney I was using my elbow to work on the sore area, and when we were discussing the blog for this month it only made sense to share this technique with you.  So, Dr. Chaney took pictures and I sat at his computer to write.  I thought others may want to how to relieve hip pain after sitting or driving for long periods.

What Causes Anterior Hip Pain?

As I’ve mentioned in posts in the past, sitting is the #1 cause of low back pain, and it also causes anterior hip pain (pain localized towards the front of the hip) because the muscles (psoas and iliacus) pass through the hip and insert into the tendons that then insert into the top of the thigh bone.  When hip pain reliefyou try to stand up, the tight muscle tendons will pull on your thigh bone.  The other thing that happens is the point where the muscle merges into the tendon will be very tight and tender to touch. You aren’t having pain at your hip or thigh bone, but at the muscular point where the muscle and tendon merge.

It’s a bit confusing to describe, but you’ll find it if you sit down and put your fingers onto the tip of your pelvis, then just slide your fingers down toward your thigh and out about 2”. The point is right along the crease where your leg meets your trunk.

The muscle you are treating is the Rectus Femoris, where it merges from the tendon into the muscle fibers.  Follow this link, thigh muscle, to see the muscle and it will be a bit easier to visualize.

You need to be pressing deeply into the muscle, like you’re trying to press the bone and the muscle just happens to be in the way.  Move your fingers around a bit and you’ll find it.

Easy Treatment for Anterior Hip Pain After Sitting

relieve hip painHere is an easy treatment for hip pain after sitting you can administer yourself.  First, sit as I am, with your leg out and slightly turned.

Find the tender point with your fingers and then put your elbow into it as shown.

It’s important to have your arm opened so the point of your elbow is on top of the spasm.  It’s a bit tricky, but if you move about a bit you’ll come on to it, and it will hurt.  Keep the pressure so it’s tolerable, not excruciating.

After you have worked on this point for a few minutes you can move to the second part of the treatment.

hip pain treatmentPut the heel of your “same-side” hand onto your thigh as close to the spasm as you can get.  Lift up your fingers so the pressure is only on the heel of your hand.  You can use your opposite hand to help give more pressure.

Press down hard and deeply slide down the muscle, going toward your knee.  You can also kneed it like you would kneed bread dough, really forcing the muscle fibers to relax.

I’m putting in a picture from a previous blog to explain how you can also treat this point of your rectus femoris by using a ball on the floor.

As shown in this picture, lie on the floor with the ball on your hip muscle, and then slightly turn your body toward the floor so the ball rolls toward the front of your body. You may need to move the ball down an inch or so to get to your Rectus Femoris.

When you feel the pain, you’re on the muscle.  Just stay there for a minute or so, and if you want you can move so the ball goes along the muscle fibers all the way to your knee.

pain free living book coverIt may be a challenge to find this point, but it’s well-worth the effort!

In my book, Treat Yourself to Pain Free Living, I teach how to treat all the muscles that cause pain from your head to your feet.

Wishing you well,

Julie Donnelly

julie donnelly

About The Author

Julie Donnelly is a Deep Muscle Massage Therapist with 20 years of experience specializing in the treatment of chronic joint pain and sports injuries. She has worked extensively with elite athletes and patients who have been unsuccessful at finding relief through the more conventional therapies.

She has been widely published, both on – and off – line, in magazines, newsletters, and newspapers around the country. She is also often chosen to speak at national conventions, medical schools, and health facilities nationwide.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

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