How Much Protein Do Athletes Need?

Written by Dr. Steve Chaney on . Posted in How Much Protein Do You Need

Position of the International Society of Sports Nutrition On Protein & Exercise

Author: Dr. Stephen Chaney

how much protein do athletes needThere is so much conflicting information about how much protein we should be getting. Some experts say we are eating too much. Others say we are eating too little. Some experts say we should just eat fruits and vegetables. Others say we should load up on meat. Some experts say athletes need more protein. Others say they get plenty of protein in the standard American diet. No wonder you are confused!

So, how much protein do athletes need?

Because of all the conflicting advice, I thought it would be worthwhile to share with you the International Society of Sports Nutrition Position Statement on protein and exercise (R. Jagr et al, Journal of the International Society of Sports Nutrition 14:20, 2017. DOI: 10.1186/s12970-017-0177-8).

How Much Protein Do Athletes Need?

 

Before summarizing the International Society of Sports Nutrition (ISSN) recommendations, I should start by pointing out that these recommendations are focused on the effect of protein on exercise performance. They are also focused more on high performance athletes than on those of us who are just trying to stay fit.

I have covered protein needs of people of all ages and exercise intensities in my article “How Much Protein Do You Need?” and will refer to that article from time to time.

Here are the ISSN recommendations:

exercise and protein#1: “An acute exercise stimulus, particularly resistance exercise, and protein ingestion both stimulate muscle protein synthesis and are synergistic”. In simple English, exercise and protein work synergistically to help you increase muscle mass.

#2: “For building and maintaining muscle mass…, an overall daily protein intake in the range of 0.6 – 0.9 gm/pound body weight/day is sufficient for most exercising individuals”. This is 1.7-2.5 times the RDA for sedentary individuals, and is more appropriate for elite athletes than for your average weekend warrior or fitness enthusiast.

Protein Requirements Calculator

They make the point that protein alone is sufficient for increasing muscle mass following resistance training. However, they also say that addition of carbohydrate to a protein supplement improves muscle glycogen recovery and reduces post-workout muscle soreness.

I also prefer some carbohydrate with a protein supplement because of a phenomenon called “protein sparing.”  In brief, in the absence of carbohydrate, some of the ingested protein is converted to glucose to restore blood glucose levels and muscle glycogen stores. If you include carbohydrate with the protein, the carbohydrate will be used to restore blood glucose & glycogen, and all the protein can be used to increase muscle mass.

#3: “There is novel evidence that suggests higher protein intake (>1.36 gm/pound body weight/day) may promote loss of fat mass in resistance-trained individuals”. This recommendation is primarily for body builders.

#4: “Optimal protein intake per serving…depends on age and [the intensity of] recent resistance exercise. General recommendations are…a dose of 20-40g”. In general, young people require less protein following exercise than older people. I have covered age-specific protein recommendations in my article “How Much Protein Do You Need?”. As for intensity of exercise, most of us engage in moderate intensity exercise and should aim for the lower dose recommended by the ISSN. The higher dose is more appropriate for elite athletes engaged in high intensity training.

leucine protein and exercise#5: “Acute protein doses should strive to contain 700-3,000 mg of leucine…in addition to a balanced array of the essential amino acids”. Older people also need more leucine than younger people. I have discussed age-related leucine needs in my article “Does Leucine Trigger Muscle Growth?”.

It is worth noting that in their position statement, the ISSN did not recommend any of the other ingredients that you often find in protein supplements.

#6: “These protein doses should be evenly distributed, every 3-4 h, across the day”. If you consume too much protein at one time, the excess will not be used for building muscle.

#7: “The optimal time period during which to ingest protein is likely a matter of individual tolerance…However, the anabolic effect of exercise is long-lasting (at least 24 h), but likely diminishes with increasing time post-exercise”. While the anabolic effect of exercise lasts for 24 hours or more, the maximum anabolic effect occurs during the first 2-4 hours after exercise. This is why a post-workout supplement is generally recommended immediately following a workout. Because there is a limit to how much protein can be consumed at any one time, additional protein should be consumed at regular intervals over the next 24 hours (recommendation #6).

#8: “While it is possible for physically active individuals to obtain their daily protein requirements through the consumption of whole foods, supplementation is a practical way of ensuring intake of adequate protein quality and quantity, while minimizing caloric intake.”

protein shakes#9: “Rapidly digested proteins that contain high proportions of essential amino acids and adequate leucine are most effective in stimulating muscle protein synthesis.”  This recommendation is most appropriate for protein(s) ingested during the acute 2-4 hour anabolic phase immediately after exercise. During the remaining 24 hours of the anabolic phase, it is more important to maintain a constant amino acid concentration in the bloodstream. For this reason, I generally recommend more slowly digested proteins, such as meat or soy, between 4 and 24 hours after exercise.

#10: “Different types and quality of protein can affect amino acid bioavailability following protein supplementation.”  Simply put, there are a lot of “junk” protein supplements out there. Look for a manufacturer with a reputation for integrity and for product quality.

#11: “Athletes should consider focusing on whole food sources of protein that contain all the essential amino acids.”  Simply put, you should avoid supplements that contain only a few selected amino acids. Instead, choose supplements that provide whole protein from natural sources. Leucine, for example, is very beneficial when added to a whole protein supplement containing all the essential amino acids, but leucine by itself would be of little value.

protein endurance#12: “Endurance athletes should focus on achieving adequate carbohydrate intake to promote optimal performance; the addition of protein may help offset muscle damage and promote recovery.”  In short, endurance athletes benefit from a combination of carbohydrate and protein, but carbohydrate is of primary importance.

#13: “Pre-sleep casein intake (30-40 g) provides increases in overnight muscle protein synthesis and metabolic rate without decreasing the overnight fat breakdown.”  The definitive studies on this have been fairly recent. This recommendation is most appropriate for elite athletes who are primarily interested in increasing muscle mass. For the rest of us, calorie considerations would outweigh the small increment in muscle mass we could gain overnight.

The above gives a summary the ISSN statement on protein and exercise and offers an answer to the question how much protein do athletes need?

 

The Bottom Line

 

This article is different from my previous articles in that it is a summary. It would be pointless to make a summary of a summary, so I have done away with “The Bottom Line.”  Read the article above for a quick summary of the International Society for Sports Nutrition position statement on protein and exercise.

 

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.

Trackback from your site.

Leave a comment

Recent Videos From Dr. Steve Chaney

READ THE ARTICLE
READ THE ARTICLE

Latest Article

Is Our Microbiome Affected By Exercise?

Posted November 6, 2018 by Dr. Steve Chaney

Microbiome Mysteries

Author: Dr. Stephen Chaney

is our microbiome affected by exerciseIn a recent post,  What is Your Microbiome and Why is it Important,  of “Health Tips From The Professor” I outlined how our microbiome, especially the bacteria that reside in our intestine, influences our health. That influence can be either good or bad depending on which species of bacteria populate our gut. I also discussed how the species of bacteria that populate our gut are influenced by what we eat and, in turn, influence how the foods we eat are metabolized.

I shared that there is an association between obesity and the species of bacteria that inhabit our gut. At present, this is a “chicken and egg” conundrum. We don’t know whether obesity influences the species of bacteria that inhabit our gut, or whether certain species of gut bacteria cause us to become obese.

Previous studies have shown that there is also an association between exercise and the species of bacteria that inhabit our gut. In particular, exercise is associated with an increase in bacteria that metabolize fiber in our diets to short chain fatty acids such as butyrate. That is potentially important because butyrate is a primary food source for intestinal mucosal cells (the cells that line the intestine). Butyrate helps those cells maintain the integrity of the gut barrier (which helps prevent things like leaky gut syndrome). It also has an anti-inflammatory effect on the immune cells that reside in the gut.

However, associations don’t prove cause and effect. We don’t know whether the differences in gut bacteria were caused by differences in diet or leanness in populations who exercised regularly and those who did not. This is what the present study (JM Allen et al, Medicine & Science In Sports & Exercise, 50: 747-757, 2018 ) was designed to clarify.  Is our microbiome affected by exercise?

 

How Was The Study Designed?

is our microbiome affected by exercise studyThis study was performed at the University of Illinois. Thirty-two previously sedentary subjects (average age = 28) were recruited for the study. Twenty of them were women and 12 were men. Prior to starting the study, the participants filled out a 7-day dietary record. They were asked to follow the same diet throughout the 12-week study. In addition, a dietitian designed a 3-day food menu based on their 7-day recall for the participants to follow prior to each fecal collection to determine species of gut bacteria.

The study included a two-week baseline when their baseline gut bacteria population was measured, and participants were tested for fitness. This was followed by a 6-week exercise intervention consisting of three supervised 30 to 60-minute moderate to vigorous exercise sessions per week. The exercise was adapted to the participant’s initial fitness level, and both the intensity and duration of exercise increased over the 6-week exercise intervention. Following the exercise intervention, all participants were instructed to maintain their diet and refrain from exercise for another 6 weeks. This was referred to as the “washout period.”

VO2max (a measure of fitness) was determined at baseline and at the end of the exercise intervention. Stool samples for determination of gut bacteria and concentrations of short-chain fatty acids were taken at baseline, at the end of the exercise intervention, and again after the washout period.

In short, this study divided participants into lean and obese categories and held diet constant. The only variable was the exercise component.

 

Is Our Microbiome Affected By Exercise?

is our microbiome affected by exercise fitnessThe results of the study were as follows:

  • Fitness, as assessed by VO2max, increased for all the participants, and the increase in fitness was comparable for both lean and obese subjects.
  • Exercise induced a change in the population of gut bacteria, and the change was comparable in lean and obese subjects.
  • Exercise increased fecal concentrations of butyrate and other short-chain fatty acids in the lean subjects, but not in obese subjects.
  • The exercise-induced changes in gut bacteria and short-chain fatty acid production were largely reversed once exercise training ceased.

The authors concluded: “These findings suggest that exercise training induces compositional and functional changes in the human gut microbiota that are dependent on obesity status, independent of diet, and contingent on the sustainment of exercise.” [Note: To be clear, the exercise-induced changes in both gut bacteria and short-chain fatty acid production were independent of diet and contingent on the sustainment of exercise. However, only the production of short-chain fatty acids was dependent on obesity status.]

 

What Does This Study Mean For You?

is our microbiome affected by exercise gut bacteriaThere are two important take home lessons from this study.

  • With respect to our gut bacteria, I have consistently told you that microbiome research is an emerging science. This is a small study, so you should regard it as the beginning of our understanding of the effect of exercise on our microbiome rather than conclusive by itself. It is consistent with previous studies showing an association between exercise and a potentially beneficial shift in the population of gut bacteria.

The strength of the study is that it shows that exercise-induced changes in beneficial gut bacteria are probably independent of diet. However, it is the first study to look at the interaction between obesity, exercise and gut bacteria, so I would interpret those results with caution until they have been replicated in subsequent studies.

  • With respect to exercise, this may be yet another reason to add regular physical activity to your healthy lifestyle program. We already know that exercise is important for cardiovascular health. We also know that exercise increases lean muscle mass which increases metabolic rate and helps prevent obesity. There is also excellent evidence that exercise improves mood and helps prevent cognitive decline as we age.

Exercise is also associated with decreased risk of colon cancer and irritable bowel disease. This effect of exercise has not received much attention because the mechanism of this effect is unclear. This study shows that exercise increases the fecal concentrations of butyrate and other short-chain fatty acids. Perhaps, this provides the mechanism for the interaction between exercise and intestinal health.

 

The Bottom Line

A recent study has reported that:

  • Exercise induces a change in the population of gut bacteria, and the change was comparable in lean and obese subjects.
  • Exercise causes an increase in the number of gut bacteria that produce butyrate and other short-chain fatty acids that are beneficial for gut health.
  • These effects are independent of diet, but do not appear to be independent of obesity because they were seen in lean subjects but not in obese subjects.
  • The exercise-induced changes in gut bacteria and short-chain fatty acid production are largely reversed once exercise training ceases.

The authors concluded: “These findings suggest that exercise training induces compositional and functional changes in the human gut microbiota that are dependent on obesity status, independent on diet, and contingent on the sustainment of exercise.”

For more details and my interpretation of the data, read the article above.

 

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.

UA-43257393-1