Tag Archive for: muscle

The Bottom Line on Essential Amino Acids

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Essential amino acids are becoming more prevalent in the sport nutrition supplement offerings. Yet there are still questions that remain, and we don’t have a total picture of who will benefit from EAA use. Let’s take a look.

Questions

Even with this new research, there’s so much we still don’t know about EAAs.

  • Is there a special proportion of EAAs that works best? In other words, should the amount of leucine or isoleucine or tryptophan be higher than other EAAs? What’s the best proportion?
  • What’s the best source? Milk, which contains whey and casein? Soy? Rice? Pea? Or a form of meat such as chicken, fish, or beef?
  • Do the EAAs compete for absorption? Does eating a complete protein such as the protein in beef or chicken inhibit the absorption of the EAAs in the protein? After all, just eating more meat could potentially be the best solution, but maybe it’s not as efficient as getting the EAAs in a stand-alone product.
  • How much muscle will athletes build in how long a time? Will it be 1% or 5% better than just eating more protein or will it be the same?
  • Should the EAAs be taken alone or as part of a protein shake?
  • When is the best time to take the EAAs in relation to a workout? Or does it really not matter? What about other nutrients taken at the same time such as carbohydrates or fats? Will they positively or negatively impact the EAAs?

There are some partial answers in the research but nowhere near enough to say “This is how you do it for the best benefit.” That’s not to say that there are no opinions, but it’s based more on limited research or personal experience than anything else.

The Bottom Line

Based on all of the available information, here is the bottom line on EAAs.

  • Everyone needs more EAAs in their diet, especially those of us over 50. (We all need to do more resistance exercise, but that’s a different Memo.) It’s more than just losing muscles mass as we age; it’s also about being able to make all the hormones we need for optimal health.
  • Eat about one gram protein per pound of body weight up to about 150 grams per day. If someone is overweight or oversized, trial and error is the only way to set an upper limit. But it’s critical for athletes and older people to hit that mark. Chicken seems to be the best profile for EAAs next to milk protein, but there’s more research needed.
  • If you get your EAAs from powders, whey protein isolate seems to have the best profile based on the content of branch-chained amino acids, but soy protein has a good profile as well. There doesn’t seem to be a perfect source yet.
  • If you want to take a separate EAA product that has no other amino acids, that’s fine. It will probably be best to take it before you work out or lift weights, but there’s good reason to take it after working out as well. About 15 to 30 minutes later, take your complete protein, whether from powders or food.

As research continues, I’ll update the recommendations as we get more answers. For now, make sure you get enough protein for health and growth based on what we know today.

What are you prepared to do today?

Dr. Chet

 

Essential Amino Acids for Older Adults

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One of the issues we all face as we get older is the loss of muscle mass; the technical term is sarcopenia. While some of the loss can be attributed to declining hormone levels as well as the decline in physical activity, we tend to eat less protein as we get older. Less protein intake means less muscle and other protein synthesis.

Researchers in Japan wanted to see if increases in muscle mass were related to protein intake, specifically EAAs. Instead of jumping right into supplementing with EAAs, they recruited 10 older men with a mean age of 69 and gathered nutritional information using a three-day dietary record. They put the men on a progressive weight training program, lifting three days per week for 12 weeks.

All men gained muscle mass, about one pound of muscle per leg. In analyzing the diet, the average protein intake was 99 grams of protein per day with 37 grams from EAAs. What they found was that those men with higher EAA intake, especially leucine, had a greater increase in muscle mass. It was even better if they had the EAAs with their breakfast.

This was a small preliminary study that examined current food intake with no intervention other than exercise. It may indicate that in order to be efficient at adding muscle mass, EAAs are important in older adults. What does this mean for you if you’re in that age group or an athlete wanting to add muscle mass? I’ll let you know on Saturday.

What are you prepared to do today?

Dr. Chet

 

Reference: J Nutr Sci vitaminol (Tokyo). 2017;63(6):379-388. doi: 10.3177/jnsv.63.379.

 

Essential Amino Acids: The Basics

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I’ve been getting many questions about essential amino acids lately. What are they? Why do I need them? Are they only for athletes? What can they do for me? In addition, I came across an interesting study that supports the use of EAAs in a specific population.

The EAAs include the amino acids phenylalanine, threonine, tryptophan, methionine, lysine, histidine, leucine, isoleucine, and valine. They’re essential because we can’t make them, but we can make other amino acids from these EAAs. In addition, three of the EAAs are designated as branch chain amino acids (BCAAs): leucine, isoleucine, and valine; they’re known as protein-building amino acids and important for building muscle.

Think of the EAAs as the rate-limiting amino acids. If we don’t have enough of them, we can’t make the other amino acids and thus, every protein made in the body can be affected. We often think only in terms of muscle, but the lack of EAAs could affect the manufacture of insulin, human growth hormone, leptin, and adiponectin to name just a few.

BCAAs have been marketed to athletes who are training to make muscle for years. Recently, EAAs have entered the arena because of their ability to make proteins that support muscle building. But that’s not the only group that may benefit as a recent study demonstrated. I’ll cover that on Thursday.

What are you prepared to do today?

Dr. Chet

 

Research Update on Sarcopenia

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We know what sarcopenia is, but what can be done about it? Recent research may give us a clue.

Researchers in the United Kingdom examined a variety of variables related to sarcopenia in a group of men. Remember, a motor unit is a nerve and all the muscle fibers to which it attaches. They looked at the differences between the size of the motor units and the total units between 48 young men, 13 non-sarcopenic elderly men, 53 pre-sarcopenic, and 28 sarcopenic men.

The motor unit potential was greater in non-sarcopenic and pre-sarcopenic men than in young men. Why would that be? The researchers suggested that the nerves are still sending out nerve shoots trying to recruit more muscle fibers. This was not the case with the sarcopenic men; their motor unit potential was much lower. That could mean that once connections are lost, there’s no way to recover muscle function including strength.

While the researchers could not answer that final question with certainty, it’s apparent that preventing potential motor unit loss is critical. How? We’ll talk about that on Saturday.

What are you prepared to do today?

Dr. Chet
Reference: J Physiol. 2018 Mar 11. doi: 10.1113/JP275520.

 

So You Lose a Little Muscle—So What?

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Any of my former students who read the Memo should remember the following definition quite well:

A motor unit is a nerve and all the muscle fibers to which it attaches.

It’s called a unit because both sides of that equation are important. Muscle fibers contract when stimulated by a nerve. Reduce the number of fibers that the nerve can attach to, and the muscle won’t generate as much force. Losing a little strength is no big deal, right? How about walking up a flight of stairs? Or even being able to maintain balance while standing? Yes—it’s a big deal.

Sarcopenia is the progressive loss of muscle strength and function as people age. How much loss? Just look at the picture from the Journal of Physiology: the loss of muscle is obvious and with that, a loss of function. Let that sink in. I’ll talk about whether anything can be done about it the rest of the week.

What are you prepared to do today?

Dr. Chet

 

Reference: J Physiol. 2018 Mar 11. doi: 10.1113/JP275520.

 

Can Vegetarian Protein Help You Build Muscle?

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People often ask me which is the best type of protein to build muscle when weight training. The reason for the question is bodybuilder and weight-training websites that condemn vegetarian protein as not good enough to build muscle. In the same issue of Medicine and Science in Sport and Exercise as the paper from Tuesday, a research study examined that question.

Researchers divided 54 men into three groups. One group got a vegetarian protein blend of soy and dairy, a second group got dairy-only protein, while the third received a maltodextrin placebo. They all performed the same weight training program for 12 weeks. The researchers then tested their strength as well as evidence of muscle growth after taking muscle biopsies.

All participants gained strength and muscle. Those who took the protein supplements gained slightly more muscle than the placebo group, but there were no differences in muscle gains between the soy-dairy blend and the whey-protein group.

This contributes to the body of research showing that it’s the protein that makes the difference, not whether it’s a vegetable or animal source of the protein. Use whichever fits your lifestyle better, but it’s doing the lifting that makes the real difference.

What are you prepared to do today?

Dr. Chet

 

Reference: MSSE. 2017 Feb 13. DOI: 10.1249/MSS.0000000000001224

 

How Exercise Affects Menopause: Muscle and Bone

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In Tuesday’s post, we looked at how menopause affects exercise. Today and Saturday we’ll look at the reverse because exercise can have powerful effects on the changes we associate with menopause.

As a woman ages, she loses bone mineral content due to decreasing hormone levels. Her muscles change as well; fast-twitch muscle fibers become more like slow-twitch fibers. Women can’t run as fast . . .

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Gaining Muscle and Losing Fat with Protein

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Can you gain muscle while losing weight? Let’s take a look at the final study in this week’s Research Update on protein.

Researchers recruited 40 young overweight men to participate in a four-week diet and exercise weight loss program with an average age of 23 and average BMI of 29.7. The subjects were randomly divided into two groups. The control group had a diet that reduced calories by 40% and provided 1.2 grams of protein per kg of body weight per day. The protein group had their intake reduced by 40% but were given 2 . . .

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Dancing Your Way to Fitness

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Does the way dancers train make them some of the fittest and leanest athletes? On Tuesday, we looked at heavy weights and fewer repetitions. Let’s look at light weights and many repetitions.

In ballroom and other forms of dance, the resistance is almost always body weight. Yes, there are lifts and there are powerful turns and jumps, but the only resistance is often body weight. Think of repeatedly doing half-squats, push-ups, or abdominal curls for hours on end, plus the muscle needed to hold . . .

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Do Dancers Rule the Fitness World?

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Dancing with the Stars began a new season last night, and once again Paula asserted that dancers have the best bodies: great musculature and shape without being unnaturally bulky. She wondered if dancing was the equivalent of exercising at high reps with low weight as opposed to typical weightlifting that emphasizes systematically increasing weight when a specific number of repetitions are met. I do as my wife commands, so this week I'm looking into the difference in results between high reps at low weight and fewer reps at high weight.

Let’s look at fewer reps at . . .

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