Alan Aragon Research Review September 2011, mm. -> Trening & Kosthold; Verdt å lese, Utgave 85

Utgave 85 – I denne utgaven: Alan Aragon Research Review September 2011:
– Editor’s Cut: Supplement spotlight: citrulline malate (A. Aragon)
– The effect of abdominal exercise on abdominal fat. (Vispute SS et al.)
Effects of a 2-y dietary weight-loss intervention on cholesterol metabolism in moderately obese men (Leichtle AB, et al.)
A higher-carbohydrate, lower-fat diet reduces fasting glucose concentration and improves β-cell function in individuals with impaired fasting glucose (Gower BA et al.)
THE EFFECTS OF CREATINE MONOHYDRATE LOADING ON ANAEROBIC PERFORMANCE AND 1-RM STRENGTH (Zuniga JM et al.)
– The 6-a-day study: effects of fruit and vegetables on markers of oxidative stress and antioxidative defense in healthy nonsmokers (Dragsted LO et al.)
In the lay press: A scientific study of the Shake Weight (really) (A. Aragon)
– Good Question: Creatine: more muscle on your body, less hair on your head? (A. Aragon)

* For å lese hele artiklene referert til i denne utgaven, må du abonnere på AARR! Anbefales for alle som arbeider med trening eller ernæring, eller et over middels interesserte.

Ukas sitat:
«I love it when I hear folks say that human adults weren’t meant to consume milk, much less the milk derived from a different animal species. Are you kidding me? So who gets to decide which parts of the cow we should consume? Let me get this straight–we can eat the cow’s muscles, but not the milk that laid the foundation for the growth of those same muscles? Huh? The logic is just too rock-solid for me.»
– Alan Aragon

Editor’s Cut: Supplement spotlight: citrulline malate:

– «…Citrulline is a non-essential amino acid that plays a key role in the urea cycle, the pathway by which ammonia is cleared from the body. Increasing the availability of citrulline can expedite ammonia clearance, thus delaying fatigue. Malate (malic acid), an intermediate in the Krebs cycle, can act as a metabolic shuttle between the cytoplasm & mitochondria, ultimately limiting the accumulation of lactic acid by redirecting it towards the production of pyruvate, which in turn can fuel aerobic activity…»

– «…About a decade ago, Bendahan et al conducted what I jokingly call the “come here study” due to its assessment of CM’s effect on finger flexion.11 Mechanistic research on CM had been done prior to this study,12,13 but this one was the first to directly measure muscle energetics during exercise. The protocol involved finger flexion repetitions done at 1.5 second intervals lifting a 6 kg weight. Using nuclear magnetic resonance spectroscopy, it was found that CM dosed at 6 g/day for 15 days resulted in a 34% increase in the rate of oxidative ATP production during exercise, and a 20% increase in the rate of phosphocreatine recovery after exercise. In addition, the subjects reported a significantly lower sensation of fatigue. Collectively, these results indicated CM’s ability to enhance aerobic energy production. Notably, this was not an industry-sponsored study….»

– Pérez-Guisado & Jakeman (14) testet de akutte effektene av 8 g CM på 16 sett med brysttrening, og CM-gruppen tok hele 59 % flere repetisjoner, og de hadde betydelig redusert stølhet (DOMS) 24 og 48 timer etter testing. 14,63 % opplevde mage-ubehag. Studien var gjort på styrketrente personer!

– Sureda et al. (15) fant positive effekter på hormonnivåer og forbrenning under trening ved 137 kg sykling hos semi-pro/elite-nivå syklister som inntok 6 g Cm 2 timer før testen.

Xtend-studien (16 – analysert i feb ’10 AARR); kanskje CM bør få noe av æren for de posotive effektene, og kanskje det er en synergistisk effekt. Studien var dog sponset av SciVation.

– «As with all supplements lacking a substantive body of human toxicological data, the possibility of adverse side-effects can’t be dismissed. At this point, the decision to use CM is a matter of how optimistically you view compounds showing a glimmer of hope. It remains to be seen whether or not CM’s recent shine is just a flash in the pan.»

* Alan Aragon: AARR September 2011:

1. Hickner RC, et al. L-citrulline reduces time to exhaustion and insulin response to a graded exercise test. Med Sci Sports Exerc. 2006 Apr;38(4):660-6. [Medline]
2. Creff AF. Controlled double-blind clinical-study against stimol placebo in the treatment of asthenia. Gazette Medicale De France 1982;89:1926–9.
3. Dauverchain J. Double-blind study of Stimol in the treatment of asthenia in older subjects. Mediterranée Médicale 1982;272:77–9.
4. Fedorova VI. Autonomic disorders in persons with asthenic syndrome and their correction with citrulline malate. Zh Nevrol Psikhiatr Im S S Korsakova. 2000;100(4):32-6. [Medline]
5. Álvares TS, et al. L-Arginine as a potential ergogenic aid in healthy subjects. Sports Med. 2011 Mar 1;41(3):233-48. [Medline]
6. Greer BK, Jones BT. Acute arginine supplementation fails to improve muscle endurance or affect blood pressure responses to resistance training. J Strength Cond Res. 2011 Jul;25(7):1789-94. [Medline]
7. Willoughby DS, et al. Effects of 7 days of arginine-alpha- ketoglutarate supplementation on blood flow, plasma L-arginine, nitric oxide metabolites, and asymmetric dimethyl arginine after resistance exercise. Int J Sport Nutr Exerc Metab. 2011 Aug;21(4):291-9. [Medline]
8. Goubel F, et al. Citrulline malate limits increase in muscle fatigue induced by bacterial endotoxins. Can J Physiol Pharmacol. 1997 Mar;75(3):205-7. [Medline]
9. Giannesini B, et al. Beneficial effects of citrulline malate on skeletal muscle function in endotoxemic rat. Eur J Pharmacol. 2009 Jan 5;602(1):143-7. Epub 2008 Nov 17. [Medline]
10. Hannestad J, et al. Citalopram reduces endotoxin-induced fatigue. Brain Behav Immun. 2011 Feb;25(2):256-9. Epub 2010 Oct 16. [Medline]
11. Bendahan D, et al. Citrulline/malate promotes aerobic energy production in human exercising muscle. Br J Sports Med. 2002 Aug;36(4):282-9. [Medline]
12. Fornaris E, Vanuxem D, Duflot JC, et al. Pharmacoclinical approach of citrulline malate activity: analysis of blood lactate during a standardised exercise. Gazette Medicale 1984;91:1–3.
13. Callis A, et al. Activity of citrulline malate on acid-base balance and blood ammonia and amino acid levels. Study in the animal and in man. Arzneimittelforschung. 1991 Jun;41(6):660-3. [Medline]
14. Pérez-Guisado J, Jakeman PM. Citrulline malate enhances athletic anaerobic performance and relieves muscle soreness. J Strength Cond Res. 2010 May;24(5):1215-22. [Medline]
15. Sureda A, et al. L-Citrulline-malate influence over branched chain amino acid utilization during exercise. Eur J Appl Physiol. 2010 Sep;110(2):341-51. Epub 2010 May 25. [Medline]
16. Stoppani J, et al. Consuming a supplement containing branched- chain amino acids during a resistance-training program increases lean mass, muscle strength and fat loss. Proceedings of the Sixth International Society of Sports Nutrition (ISSN) Conference and Expo. June 2009. [JISSN]

The effect of abdominal exercise on abdominal fat. (Vispute SS et al.): En studie fra september 2011 undrsøkte effekten av magetrening på magefett, og fant ingen effekt – hverken lokalisert (spot reduction) eller totalt. Totalt 75 min trening i uka var nok ikke tilstrekkelig for å ha en effekt på kroppsmassen totalt sett. Muskulær utholdenhet i magen ble forbedret i treningsgruppen.

Andre studier har dog funnet indikasjoner på at ‘spot-reduction’/punktforbrenning er mulig (1-3), men et spørsmål er vel likevel hvor stor betydning det har så lenge hele kroppen trenes. (mage, core, stabiliseringstrening)

* Alan Aragon: AARR September 2011:

Vispute SS, Smith JD, LeCheminant JD, Hurley KS. The effect of abdominal exercise on abdominal fat. J Strength Cond Res. 2011 Sep;25(9):2559-64. Pubmed.
1. Mohr DR. Changes in waistline and abdominal girth and subcutaneous fat following isometric exercises. Res Q. 1965 May;36:168-73. [Medline]
2. Noland M, Kearney JT. Anthropometric and densitometric responses of women to specific and general exercise. Res Q. 1978 Oct;49(3):322-8. [Medline]
3. Stallknecht B, et al. Are blood flow and lipolysis in subcutaneous adipose tissue influenced by contractions in adjacent muscles in humans? Am J Physiol Endocrinol Metab. 2007 Feb;292(2):E394-9. Epub 2006 Sep 19. [Medline]

Effects of a 2-y dietary weight-loss intervention on cholesterol metabolism in moderately obese men (Leichtle AB, et al.): En studie fra september 2011 undersøkte en 2-årig vektreduksjonsprotokoll’s effekt på kolesterol metabolismen, og fant at alle tre diettene (The low-fat (LF), Mediterranean (M) & Low-Carb (LC) ga omtrentlig like resultater.

Lavkarbo/Low-Carb gruppen mistet litt mer kroppsvekt (LF: 4%, M: 5%, LC: 8%), men de ca 2 kg totalt over 2 år er ikke betydelig i den virkelige verden.

* Alan Aragon: AARR September 2011:

Leichtle AB, Helmschrodt C, Ceglarek U, Shai I, Henkin Y, Schwarzfuchs D, Golan R, Gepner Y, Stampfer MJ, Blüher M, Stumvoll M, Thiery J, Fiedler GM. Effects of a 2-y dietary weight-loss intervention on cholesterol metabolism in moderately obese men. Am J Clin Nutr. 2011 Nov;94(5):1189-95. Epub 2011 Sep 21. Pubmed.

A higher-carbohydrate, lower-fat diet reduces fasting glucose concentration and improves β-cell function in individuals with impaired fasting glucose (Gower BA et al.): En studie fra september 2011 fant at en høyere karbohydrat, lavere fett diett var førte til bedre endringer i glukose konsentrasjoner og β-cell funksjon enn en lavere karbohydrat, høyere fett diett, i personer med hemmet fastende glukose (notater: diabetes dype 2, sukkersyke, lavkarbo, lav-karb, low-carb, karbohydratinntak, insulin sensitivitet, insulin insensitivitet).

– «But notice, the lower-carb menu gets some of its fat from margarine & corn chips, both of which are missing from the higher-carb sample menu. If, for example, the lower-carb/higher-fat treatment was achieved through other sources like fatty fish, almonds, walnuts, and/or avocados, then it’s almost certain that the less favorable outcomes in the lower-carb group would not be replicated….»

– «In contrast to the scant & marginally relevant research cited by the authors, there is a relative abundance of randomized controlled trials on humans showing the superiority of lower carbohydrate intakes over higher-carbohydrate intakes for alleviating complications of the metabolic syndrome. A review by Acheson et al (cited in the present study) states that a low- carbohydrate ketogenic diet has shown better body weight and fat losses, improved insulin sensitivity and glucose control than a low-fat diet.9 A more recent review by Layman et al concluded that low-carbohydrate/high-protein (LC/HP) diets have shown superior benefits on glycemic control, including reducing fasting blood glucose, postprandial glucose and insulin responses, and the percentage of glycated hemoglobin.10 Subsequently, in a systematic review of randomized controlled trials, Hession et al concluded that LC/HP diets are more effective at 6 months and are as effective, if not more, as low-fat diets in reducing weight and cardiovascular disease risk up to 1 year.11…»

* Alan Aragon: AARR September 2011:

1) Gower BA, Goree LL, Chandler-Laney PC, Ellis AC, Casazza K, Granger WM. A higher-carbohydrate, lower-fat diet reduces fasting glucose concentration and improves β-cell function in individuals with impaired fasting glucose. Metabolism. 2011 Sep 22. [Epub ahead of print]. Pubmed.

9. Acheson KJ. Carbohydrate for weight and metabolic control: where do we stand? Nutrition. 2010 Feb;26(2):141- 5. [Medline]

10. Layman DK, et al. Protein in optimal health: heart disease and type 2 diabetes. Am J Clin Nutr. 2008 May;87(5):1571S-1575S. [Medline]

11. Hession M, et al. Systematic review of randomized controlled trials of low-carbohydrate vs. low-fat/low-calorie diets in the management of obesity and its comorbidities. Obes Rev. 2009 Jan;10(1):36-50. [Medline]

 

THE EFFECTS OF CREATINE MONOHYDRATE LOADING ON ANAEROBIC PERFORMANCE AND 1-RM STRENGTH (Zuniga JM et al.): En studie fra september 2011 undersøkte effekten av 7 dagers ladning med kreatin monohydrat på anaerobisk ytelse og 1RM styrke/maksimal styrke, og fant at kreatin-gruppen hadde betydelig bedre økninger i ‘mean power’ (MP), men fant ingen betydelig forskjell i ‘peak power’ (PP) eller 1RM.

– «…The present study’s results are in partial agreement with Hamilton et al, who found that creatine dosed at 25 g for 7 days did not increase maximal strength in internal rotation or elbow flexion, but it did delay fatigue in the latter movement.12 As well, Syrotuik et al observed a lack of 1-rep max strength effect of creatine during a 5-day loading phase.13 In contrast to these two studies, Volek et al observed a significant increase in bench press 1-rep max (with no improvement in the placebo group) from CM dosed at 25 g/day for a 7-day loading period. Another difference from the present trial reported by Volek was a significant gain in total bodyweight (1.4 kg) in the creatine group….»

– En potensiell forklaring på forskjellen i resultatene til Volek et al. kan være at Volek et al. brukte styrketrente personer.

* Alan Aragon: AARR September 2011:

Zuniga JM, Housh TJ, Camic CL, Hendrix CR, Mielke M, Johnson GO, Housh DJ, Schmidt RJ. THE EFFECTS OF CREATINE MONOHYDRATE LOADING ON ANAEROBIC PERFORMANCE AND 1-RM STRENGTH. J Strength Cond Res. 2011 Sep 14. [Epub ahead of print]. Pubmed.

12. Hamilton KL, et al. Oral creatine supplementation and upper extremity anaerobic response in females. Int J Sport Nutr Exerc Metab. 2000 Sep;10(3):277-89. [Medline]

13. Syrotuik D, et al. Absolute and relative strength performance following creatine monohydrate supplementation combined with periodized resistance training. J strength Cond Res. 2000;14: 182-190. [JSCR]

14. Volek JS, et al. Creatine supplementation enhances muscular performance during high-intensity resistance exercise. J Am Diet Assoc. 1997 Jul;97(7):765-70. [Medline]

 

The 6-a-day study: effects of fruit and vegetables on markers of oxidative stress and antioxidative defense in healthy nonsmokers (Dragsted LO et al.): Less Recent Gem: En studie fra juni 2004 undersøkte effekten av frukt og grønnsaker på markører av oksidativt stress/oxitative stress og antioksidant forsvar/antioxidant defense i friske ikke-røykere. Det var 3 grupper: En gruppe uten frukt/grønt, en med 600 g frukt/grønt daglig, og en placebo gruppe med placebo pille og ingen frukt/grønt, og en gruppe som fikk et kosttilskudd/vitamintilskudd utviklet for å inneholde samme mengde vitaminer og mineraler som de 600 g med frukt og grønt som frukt/grønt-gruppen fikk i seg inneholdt. Både frukt/grønt og kosttilskudd-gruppen hadde forbedringer, men frukt/grønt dietten var mer effektiv enn kosttilskudd gruppen (notater: hele matvarer er bedre enn kosttilskudd, vitamintilskudd, vitamin/mineral.)

– «These effects seem to be influenced mainly by non-nutritive antioxidants. This means that nutrients such as those given to the supplement group (full list here) cannot be expected to exert the same protective effects as plant foods. Given the limitations of this study, the protective effects were potentially understated….»

– (17): «…“These findings are in good accordance with the increasing evidence that diets rich in fruit and vegetables have a protective effect against CVD and lend further support to dietary recommendations for an increased intake of fruit and vegetables….»

* Alan Aragon: AARR September 2011:

1) Dragsted LO, Pedersen A, Hermetter A, Basu S, Hansen M, Haren GR, Kall M, Breinholt V, Castenmiller JJ, Stagsted J, Jakobsen J, Skibsted L, Rasmussen SE, Loft S, Sandström B. The 6-a-day study: effects of fruit and vegetables on markers of oxidative stress and antioxidative defense in healthy nonsmokers. Am J Clin Nutr. 2004 Jun;79(6):1060-72. Pubmed.

15. Serafini M, et al. Effect of changes in fruit and vegetable intake on plasma antioxidant defenses in humans. Am J Clin Nutr. 2005 Feb;81(2):531-2; author reply 532-4. [Medline]

16. Møller P, et al. No effect of 600 grams fruit and vegetables per day on oxidative DNA damage and repair in healthy nonsmokers. Cancer Epidemiol Biomarkers Prev. 2003 Oct;12(10):1016-22. [Medline]

17. Dragsted LO, et al. Biological effects of fruit and vegetables. Proc Nutr Soc. 2006 Feb;65(1):61-7. [Medline]

 

In the lay press: A scientific study of the Shake Weight (really) (A. Aragon): En studie fra september 2011 (1) undersøkte ‘shake weight’, og fant større muskelaktivering (EMG) i shake-weight-gruppen sammenlignet med kun manualer. Faktum er dog at det ikke sammenlignes med tyngre vekter, og det er naturligvis ikke mulig å løfte like tunge ‘shake weight’ vekter som vanlige vekter, så studien er rimelig irrelevant.

Videre er ikke EMG (Electromyography) signal et godt mål for aktiviteten i hele muskelen; «…“Thus, the surface EMG signal usually does not reflect the electrical activity of the entire muscle, and it is inappropriate to conclude that a certain exercise is in some way better than another exercise based on EMG amplitude values. Furthermore, the EMG signal can be influenced by factors that are different for each exercise, such as biomechanical factors and movement speed…»

* Alan Aragon: AARR September 2011:

1. Porcari J, et al. Does the Shake Weight live up to its hype? J Sports Sci Med. 2011 Sep;10:598-99. [JSSM]

2. De Luca CJ. The use of surface electromyography in biomechanics. J Applied Biomech. 1997;13:135-63. [JAB]

3. Beck TW. Applications of surface electromyography in strength and conditioning. Hot Topics, Feb 2008 [NSCA]

 

Good Question: Creatine: more muscle on your body, less hair on your head? (A. Aragon):

En studie (5) fant at Kreatin supplementering økte DHT (dihydrotestosterone) nivåer, noe som kan øke sjansen for tap av hår på hodet, og øke størrelsen på prostata (benign). Det er dog kun en studie som har vist dette, og det trengs flere studier for å bekrefte en slik effekt – det er ‘far-fetched‘.

- «…It’s interesting that creatine was able to raise DHT in a seemingly dose-dependent manner. However, it’s also clear that this short, poorly disclosed study leaves a lot of questions hanging. So, to address the initial question, the evidence indicting creatine supplementation as a hair loss agent is far- fetched at this point. Green makes the solid point that these results would need replication after verification that the supplement was free of androgenic contaminants. From an anecdotal standpoint, I haven’t observed a higher prevalence of balding athletes on creatine compared to those who aren’t on it, nor have I received reports or complaints of hair loss from male clients related to creatine use. Ultimately, if you’re worried enough, there’s a simple solution: don’t use the supplement. This wouldn’t be a complete loss; in fact, it might force you to beef up the rest of your programming to compensate for the sacrifice….» (notater: Kreatin Monohydrate, CM, kosttilskudd, baldness, skallet).

* Alan Aragon: AARR September 2011:

1. Zhou ZX, et al. Specificity of ligand-dependent androgen receptor stabilization: receptor domain interactions influence ligand dissociation and receptor stability. Mol Endocrinol. 1995 Feb;9(2):208-18. [Medline]

2. Green G. Creatine supplementation and DHT:T ratio in male rugby players. Clin J Sport Med. 2010 May;20(3):220; author reply 220-2. [Medline]

3. Geyer H, et al. Analysis of non-hormonal nutritional supplements for anabolic-androgenic steroids – results of an international study. Int J Sports Med. 2004 Feb;25(2):124-9. [Medline]

4. Watson P, et al. Urinary nandrolone metabolite detection after ingestion of a nandrolone precursor. Med Sci Sports Exerc. 2009 Apr;41(4):766-72. [Medline]

5. van der Merwe J, Brooks NE, Myburgh KH. Three weeks of creatine monohydrate supplementation affects dihydrotestosterone to testosterone ratio in college-aged rugby players. Clin J Sport Med. 2009 Sep;19(5):399-404. Pubmed.

 

Comments are closed