Archive for the ‘Sports Nutrition’ Category

Soy Protein, Weightlifting, and Testosterone

Monday, December 30th, 2013

A reader asked me to comment on a study comparing soy protein, whey protein, and a carbohydrate placebo and their effects on hormones (1).

The study was mainly conducted to see if soy increased estrogen levels. Unsurprisingly, it did not.

On all 3 supplements, testosterone levels went up during the workout. But compared to both whey and carbohydrate placebo, testosterone levels were not sustained as high post-workout. And cortisol, which can break down muscle tissue for energy, was higher on the soy and carbohydrate regimens than on whey.

The study was done on 10 young men who took each supplement for 2 weeks, with washout periods between regimens. The supplements were taken 30 minutes before a bout of exercise: 6 sets of squats, 10 repetitions each, 2 minutes rest between sets, weight was 80% of their maximum. The hormones were measured before, during, and at a number of times after the exercise up to one hour.

All 3 supplements were 80 calories worth of energy.

It’s possible that the lower testosterone levels are a result of either the much lower amounts of leucine in soy versus whey protein (about 39% lower) or due to the isoflavones. The authors of the study say, “The majority of evidence from previous research on isoflavones alone has shown no effect on testosterone,” making me think it’s the lower leucine leading to lower testosterone.

As for the cortisol, that soy didn’t perform as well as carbohydrate is odd and might be due to the fairly intense workout, soy and carbohydrate caused higher cortisol levels. When I lift weights, I try not to push my muscles to the point where I’m breaking down muscle for a significant portion of energy, and six intense sets of squats to 10 reps seems like a lot. The carbohydrate, or the extra leucine in the whey (which muscles can use for energy), could have been enough to prevent muscle from being degraded for energy.

It was not clear from the write-up whether the participants were blinded to which regimen they were on, though I assume they were. If not, that could have played a role.

More research is needed – we don’t even know if this would result in a noticeable difference in strength gains, particularly on a different weight-lifting program that isn’t quite so focused on so many reps for the same muscle groups.

But if you are a serious weightlifter and this worries you, adding some leucine to your soy protein powder, or a non-soy protein powder, might be the way to go. Or perhaps just carbohydrate instead, to prevent the cortisol response.

The Vegetarian Resource Group has information on where leucine is sourced in their 2011 article, Leucine, Isoleucine, and Valine May Be Derived from Duck Feathers or Human Hair.

Addendum 12-31-2013:

For testosterone, whey and carbohydrate achieved similar results. Soy was not as high from 5 to 30 minutes post exercise, but was about the same at 60 minutes. Although the differences were statistically significant, they were not all that great – the biggest difference was about 30% between soy and whey.

For cortisol, I had said that soy didn’t perform as well as carbohydrate, but the differences were so small that I shouldn’t have said this. Soy and carbohydrate resulted in statistically significant, higher levels than whey at 5, 15, and 30 minutes post exercise. The biggest difference between soy and whey was about 45%.

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References

1. Kraemer WJ, Solomon-Hill G, Volk BM, Kupchak BR, Looney DP, Dunn-Lewis C, Comstock BA, Szivak TK, Hooper DR, Flanagan SD, Maresh CM, Volek JS. The effects of soy and whey protein supplementation on acute hormonal reponses to resistance exercise in men. J Am Coll Nutr. 2013;32(1):66-74. | link

Update: Leucine, Whey and Rice Protein

Friday, August 23rd, 2013

On June 17, I made a post about a study that had found that rice protein was as effective at increasing muscle mass as whey protein (see Leucine, Whey and Rice Protein). The study was described in a press release, I never found an actual published paper on it.

Pete from VeganBodyBuilding.org pointed out a podcast in which one of the researchers who conducted the study, Jacob Wilson, says that the press release is misleading (click here for the podcast, the part I’m referring to is in the first few minutes).

Dr. Wilson says that because the study used so much protein powder, 48 g of protein to be exact, there was enough leucine provided by the rice protein to achieve similar results to the whey protein. He says that at a lower protein amount, such as 25 g, whey protein is superior because of it’s higher leucine content which has been shown in many studies. From what I could gather, Dr. Wilson considers 3 g of leucine to be necessary to begin muscle synthesis in any given serving of protein.

Leucine, Whey and Rice Protein

Monday, June 17th, 2013

In January, I made a post saying that there was scant evidence that branched chain amino acids (BCAA) are important for sports nutrition (Branched Chain Amino Acids and Exercise). In response, a reader, who is a bodybuilder, told me that while BCAAs might not be important, leucine (one of the three BCAA) is likely important and is probably the reasons why whey protein powder has been shown to be better than soy for building muscle.

The reader passed on some abstracts and I found some others.

One was a study that showed that after 12 weeks of exercise in untrained men, 4 g/day of leucine led to a 41% increase in strength compared to a 31% increase for the placebo which was lactose. There were no differences in muscle mass. Okay, but is a 10% greater increase in untrained men really enough to worry about? Assuming that just eating 4 more grams of protein per day wouldn’t be just as good, I’d be surprised if the lactose group wouldn’t catch up if given a few more weeks of training.

Another two abstracts were studies comparing whey protein to soy: one in older men (2) and one in younger men (3). Both were simply measuring muscle synthesis one time after one bout of exercise. Free versions of both studies are linked from the abstracts below (I didn’t bother reading them). I don’t think these studies prove much and I don’t know if there are more impressive studies showing whey protein to be superior to soy.

Then in March, a study was reported that showed that rice protein was as effective as whey protein in increasing muscle mass (4). As of today, it does not appear to have been published in a peer-reviewed journal. This study was better designed (for our purposes) in that it was done on men who had been already involved in weight training. It was double-blinded and after 8 weeks of supplementing with one of the proteins at 48 g/day, there was significant increases in strength and muscle mass. There was no placebo group so who knows if either type of protein was necessary – perhaps just taking part in a study would be enough motivation to work out harder and have some gains in muscle mass.

In short, I don’t think there’s anything to worry about for vegan bodybuilders who are concerned that their soy or rice protein powders are not giving them the same edge as bodybuilders using whey protein.

Please note that I am not philosophically opposed to the idea that plant proteins might be inferior or to supplementing for better athletic performance. I think there is good evidence that elite vegan athletes might benefit from creatine (for recreational athletes, creatine’s probably not worth the hassle). But one should be very skeptical when it comes to sports nutrition supplements – there is a lot of money and enthusiasm behind finding supplements that can improve performance, but most turn out to be useless.

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References

1. Ispoglou T, King RF, Polman RC, Zanker C. Daily L-leucine supplementation in novice trainees during a 12-week weight training program. Int J Sports Physiol Perform. 2011 Mar;6(1):38-50. | link

2. Yang Y, Churchward-Venne TA, Burd NA, Breen L, Tarnopolsky MA, Phillips SM. Myofibrillar protein synthesis following ingestion of soy protein isolate at rest and after resistance exercise in elderly men. Nutr Metab (Lond). 2012 Jun 14;9(1):57. | link

3. Tang JE, Moore DR, Kujbida GW, Tarnopolsky MA, Phillips SM. Ingestion of whey hydrolysate, casein, or soy protein isolate: effects on mixed muscle protein synthesis at rest and following resistance exercise in young men. J Appl Physiol. 2009 Sep;107(3):987-92. | link

4. Dutch, A. First Double Blind Study Proves Plant-based Rice Protein Has Identical Benefits To Animal-based Whey Protein. PR Newswire. March 11, 2013. | link

Dr. Greger’s Volume 12

Sunday, February 10th, 2013

Dr. Greger has been posting videos at NutritonFacts.org from Volume 12 of his Latest in Clinical Nutrition series. But if your workplace does not allow plant-based-nutrition-porn to be played on your computer at work, you might want to get the DVD (click here).

Volume 12 covers fibromyalgia, coconut oil, gargling to prevent colds, and tons on flaxseeds and their ability to prevent prostate cancer, breast cancer, and type 2 diabetes. Dr. Greger does not back off his pro-antioxidant stance. He also has a section on dried fruit suggesting that raisins are just as effective as sports gels for energy while working out.

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Branched Chain Amino Acids and Exercise

Tuesday, January 15th, 2013

Question:

I have a plan for 2013 to increase my muscle mass a bit and have started researching some of the vegan fitness sites. One suggestion is to take a branched chain amino acids (BCAA) supplement right before and after workouts. Is there research showing it to be useful? Are there any health drawbacks? Are there any known vegan brands?

Answer:

There are three BCAA: leucine, isoleucine, and valine. They are essential amino acids (the body doesn’t synthesize them on its own), but are found prevalently in plant foods.

In their position paper, Nutrition and Athletic Performance, the American College of Sports Medicine (ACSM) and the Academy of Nutrition and Dietetics (AND) list BCAA in the category of “Ergogenic aids that do not perform as claimed.” (Ergogenic aid means something that increases the ability to exercise.)

Nancy Clark’s Sports Nutrition Guidebook (2003) doesn’t even list BCAA in the index, which is rather surprising given how often I get the question about them (three times in the last few weeks).

Usually, my pat answer is to cite the ACSM position paper and be done with it. But this time I decided to look into it more than I have previously. The only review article I found that promised to be of any value was a 2009 article A Primer On Branched Chain Amino Acids (PDF), by Starkie Sowers, CN, of Huntington College of Health Sciences.

It’s an impressive read, but once you delve into the abstracts of the citations, it loses its luster. My summary of the research I found is that taking BCAA before a workout can prevent fatigue and the metabolizing of muscle protein for energy, but so will eating any old protein or carbohydrate. The one clinical trial cited in Sowers’ review (and the only one I could find) actually found no effect of BCAA above carbohydrate in preventing exercise fatigue (2).

There appears to be very little research done on BCAA since the 90s. Anyone interested in seeing a list of studies can click here for those related to the clinical trial mentioned above.

If after reading the above, anyone still wants to supplement with BCAA, I do not know if there are vegan brands. That is a job for Google. ☺

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References

1. Position of the American Dietetic Association, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and Athletic Performance. J Am Diet Assoc. 2009;109:509-527. | link

2. Davis JM, Welsh RS, De Volve KL, Alderson NA. Effects of branched-chain amino acids and carbohydrate on fatigue during intermittent, high-intensity running. Int J Sports Med. 1999 Jul;20(5):309-14. | link

Greger on Beets, Nitrates, and Athletic Performance

Friday, March 23rd, 2012

Never one to shy away from talking about the benefits of greens, Dr. Michael Greger has a very interesting blog post, Using Greens to Improve Athletic Performance, that highlights his series of videos on nitrates, nitrites, and nitric oxide which are now available on NutritionFacts.org.

To sum it up, beets and many dark leafy greens contain nitrates which can improve athletic performance, by making oxygen usage more efficient, via the body turning the nitrates into nitrites and then into nitric oxide.

But if nitrites from plant foods can be beneficial, what about the nitrites added to cured meat which are supposed to be so harmful? It turns out that in the presence of vitamin C, nitrites from plants are converted to nitric oxide, while the nitrites in meat tend to be turned into nitrosamines which are, in turn, thought to be the culprit in cured meats.

Germany’s Strongest Man Is A Vegetarian

Thursday, August 11th, 2011

Good news from Germany:

Germany’s Strongest Man Is A Vegetarian

Excerpt:

Now I have proven finally, that being vegetarian makes you a better athlete!

It certainly proves that being vegetarian does not prevent someone from being extremely strong.

Creatine Improves Cognition in Vegetarians

Wednesday, October 13th, 2010

Breaking news…from 2003!

I recently became aware of the following and updated the VeganHealth.org page on creatine with it:

A 2003 study of 27 lacto-ovo vegetarian and 18 vegan college students found that supplementing with 5 g of creatine per day for six weeks increased their mental capacity (1). You can get a free copy of this study at the link below under References.

There was no omnivore group so it is not clear if the supplementation would have also worked for omnivores. But in other studies on omnivores:

- Six weeks of creatine supplementation of .03 g/kg body weight per day did not improve cognitive function in a group of young adult omnivores, but the amount of creatine was only about 1 to 1.5 g/day (2).

- In elderly omnivores, four doses of 5 g of creatine per day for one or two weeks increased their cognitive function in some but not all measurements (3).

References

1. Rae C, Digney AL, McEwan SR, Bates TC. Oral creatine monohydrate supplementation improves brain performance: a double-blind, placebo-controlled, cross-over trial. Proc Biol Sci. 2003 Oct 22;270(1529):2147-50.

2. Rawson ES, Lieberman HR, Walsh TM, Zuber SM, Harhart JM, Matthews TC. Creatine supplementation does not improve cognitive function in young adults. Physiol Behav. 2008 Sep 3;95(1-2):130-4. Epub 2008 May 15.

3. McMorris T, Mielcarz G, Harris RC, Swain JP, Howard A.Creatine supplementation and cognitive performance in elderly individuals. Neuropsychol Dev Cogn B Aging Neuropsychol Cogn. 2007 Sep;14(5):517-28. (Abstract)

Carnosine & beta-Alanine Update

Tuesday, May 25th, 2010

Thanks to a reader, Ron, who referred me to an abstract showing that vegetarians had lower muscle levels of carnosine, I have updated the VeganHealth page on carnosine and beta-alanine to suggest that vegetarians may very well be able to improve their athletic performance by supplementing with beta-alanine. Link.

Carnosine and beta-Alanine

Friday, September 11th, 2009

Someone asked me about carnosine a few months ago. I didn’t know much about it at the time, so I looked into it and here are the results:

http://www.veganhealth.org/articles/carnosine

Quick summary: No need to worry about it unless you are a serious athlete interested in experimenting with supplements that haven’t been tested long-term.