عنوان مقاله [English]
Animal studies have reported very useful properties including weight loss and improved body composition for conjugated linoleic acid (CLA). However, there is limited information about the combined effect of resistance training and CLA supplementation. Therefore, the effect of CLA supplementation and resistance training on body composition, serum leptin and muscle strength in non-athlete men was examined in this study. In a quasi-experimental trial with double-blind design, 23 non-athlete men were randomly assigned to two groups: training + supplement (n=11), and training + placebo (n=12). Both groups performed 6 weeks (3 sessions per week) of resistance training program based on the Kramer (2004) protocol. The experimental group received 3 capsules (1000 mg) of CLA supplement and the control group ingested 3 capsules of placebo (olive oil) per day. Muscular strength, body composition and serum leptin were measured in the beginning and at the end of the study. Data were analyzed using dependent and independent t tests. Based on the findings, CLA + resistance training supplementation significantly decreased fat mass and serum leptin and significantly increased non-fat mass compared with placebo + resistance training (P˂0.05) while the lower and upper body strength of both groups were not significantly different. According to the results, it can be stated that resistance training combined with CLA supplementation can improve body composition and decrease serum leptin in non-athlete men. But it does not necessarily lead to a significant improvement in lower and upper body strength.
4. Belury, M.A., Mahon, A., Banni, S. (2003). "The Conjugated Linoleic Acid (CLA) isomer, t10c12-CLA, is inversely associated with changes in body weight and serum leptin in subjects with type 2 diabetes mellitus". J Nutr., Vol. 133, No. 1, PP: 257-60.
5. Berven, G., Bye, A., Hals, O. (2000)." Safety of conjugated linoleic acid (CLA) in overweight or obese human volunteers". Eur J Lipid Sci Technol., Vol. 102, PP: 455– 62.
6. Bhattacharya, A., Rahman, M.M., McCarter, R., O'Shea, M., Fernandez, G. (2005). "The combination of dietary conjugated linoleic acid and treadmill exercise lowers gain in body fat mass and enhances lean body mass in high fat fed male mice". J Nutr., Vol. 135, PP: 1124-30.
7. Blankson, H., Stakkestad, J.A., Fagertun, H., Thom, E.,Wadstein, J., Gudmundsen, O. (2000). "Conjugated linoleic acidreduces body fat mass in overweight and obese humans". J Nutr., Vol. 130, PP: 2943–8.
8. Brzycki, M. (1993). "Strength testing-Predicting a one-rep max from a reps-to-fatigue". J. Phys. Health Edu. Recreat. Dance., Vol. 64, No. 1, PP: 88-90.
9. Colakoglu, S., Colakoglu, M., Taneli, F., Cetinoz, F., Turkmen, M. (2006). "Cumulative effects of conjugated linoleic acid and exercise on endurance development, body composition, serum leptin and insulin levels". J Sports Med Phys Fitness., Vol. 46, No.4, PP: 570-7.
10. Cornish, S.M., Candow, D.G., Jantz, N.T., Chilibeek, P.D., Little, J.P., Forbes, S., Abeysekara, S., Zello, G.A. (2009). "Conjugated Linoleic Acid Combined With Creatine Monohydrate and Whey Protein Supplementation During Strength Training". J Sport Nutrition and Exercise Metabolism., Vol. 19, PP: 79-96.
11. Diaz, M.L.,Watkins B.A., Anderson, R.A,. Campbeel, w.w .(2008). "Chromium picolinate and conjugated linoleic acid do not synergistically influence diet- and exercise-induced changes in body composition and health indexes in overweight women". J. Nutr. Biochem., Vol. 19, PP: 61-68.
12. Eyjolfson, V., Spriet, L.L., Dyck, D.J. (2004). "Conjugated linoleic acid improves insulin sensitivity in young, sedentary humans". Med Sci Sports Exerc., Vol. 36, PP: 814 –20.
13. Gaullier, J.M., Halse, J., Hoivik, H.O., Hoye, K., Syvertsen, C., Nurminiemi, M., et al. (2007). "Six months supplementation with conjugated linoleic acid induces regional-specific fat mass decrease in overweight and obese". Br J Nutr., Vol. 97, PP: 550-60
14. Gaullier, J.H., Hoye, K., Kristiansen, K., Fagertun, H., Vik, H. (2005). "Supplementation with conjugated linoleic acid for 24 months is well tolerated by and reduces body fat mass in healthy, overweight humans". J Nutr., Vol. 135, No. 4, PP: 778-84.
15. Hurley, B.F., Roth, S.M.( 2000). "Strength training in the elderly". sport med., Vol. 30, No. 4, PP: 249-261.
16. Jackson, A.S., Pollock, M.L., Ward, A. (1980). "Generalized equations for predicting body density of women". Medicine and Science in Sports and Exercise., Vol. 12, No. 3, PP: 175-81.
17. Jiang, J., Wolk, A., Vessby, B. (1999). "Relation between the intake of milk fat and the occurrence of conjugated linoleic acid in human adipose tissue". Am J Clin Nutr., Vol. 70, PP: 21-7.
18. Kreamer, W.J ., and Rataness, N.A. (2004) . "Fundamental of resistance training: progression and exercise prescription." Med Sci Sports Exerc., Vol. 36, PP: 674-688.
19. Kreider, R. B., Ferreira, M. P., Greenwood, M., Wilson, M., and Almada, A. L. (2002). "Effects of conjugated linoleic acid supplementatio during resistance training on body composition, bone density, strength, and selected hematological markers". J. Strength Cond. Res., Vol. 16, PP: 325–334.
20. Lambert, E.V., Goedecke, J.H.,. Bluett, K,. Heggie, K,. Claassen, A .( 2007). "Conjugated linoleic acid versus high-oleic acid sunflower oil: effects on energy metabolism,glucose tolerance, blood lipids, appetite and body composition in regularly exercising individuals". Br. J. Nutr., Vol. 97, PP: 1001-1011.
21. Larsen, T.M., Toubro, S., Gudmundsen, O., Astrup, A. (2006). "Conjugated linoleic acid supplementation for 1 y does not prevent weight or body fat regain". Am J Clin Nutr., Vol. 83, No. 3, PP: 606-12.
22. Laso, N., Brugue, E., Vidal, J., Ros, E., Arnaiz, J.A., Carne, X., etal. (2007). "Effects of milk supplementation with conjugated linoleic acid (isomers cis-9, trans-11 and trans-10, cis-12) on body composition and metabolic syndrome components". Br J Nutr., Vol. 98, No. 4, PP: 860-7.
23. Lin, H., Boylston, T.D., Chang, M.J., Luedecke, L.O., Shultz, T.D. (1995)." Survey of the conjugated linoleic acid contents of dairy products". J Dairy Sci., Vol. 78, PP: 2358-65.
24. Mougios, V., Matsakas, A., Petridou, A., Ring, S., Sagredos, A., Melissopoulou, A. (2001)." Effect of supplementation with conjugated linoleic acid on human serum lipids and body fat". J Nutr Biochem., Vol. 12, PP: 585–94.
25. Nazare, J.A., Perriere, dl.A.B., Bonnet F., Desage, M., Peyrat, J., Maitrepierre, C., et al. (2007). "Daily intake of conjugated linoleic acid enriched yoghurts: Effects on energy metabolism and adipose tissue gene expression in healthy subjects". Br J Nutr., Vol. 97, No. 2, PP: 273-80.
26. Petridou, A., Mougios, V., Sagredos, A. (2003). "Supplementation with CLA: isomer incorporation into serum lipids and effect on body fat of women". Lipids., Vol. 38, PP: 805–11.
27. Pinkoski, C., Chilibeck, P.D., Candow, D.G., Esliger, D., Ewaschuk, J.B., Farthing, M., Jonathan, P., Zella, G. (2006). "The effects of conju-gated linoleic acidsupplementation during resistance training". Med Sci Sports Exerc., Vol . 38, No. 2, PP: 339-348.
28. Risérus, U., Arner, P., Brismar, K., Vessby, B. (2002). "Treatment with dietarytrans10cis12 conjugated linoleic acid causes somer-specific insulin resistance in obese men with the metabolic syndrome". Diabetes Care., Vol. 25, PP: 1516 –21.
29. Risérus, U., Vessby, B., Arnlov, J., Basu, S. (2004). "Effects of cis-9,trans-11 conjugated linoleic acid supplementation on insulin sensitivity, lipid peroxidation, and proinflammatory markers in obese men". Am J Clin Nutr., Vol. 80, PP: 279–83.
30. Ritzenthaler, K.L., McGuire, M.K., Falen, R., Shultz, T.D., Dasgupta, N., McGuire, M.A. (2001). "Estimation of conjugate linoleic acid intake by written dietary assessment methodologies underestimates actual intake evaluated by food duplicate methodology". J Nutr., Vol. 131, PP: 1548-5.
31. Rosa, G., Cruz, L., Mello, D.B.d., Fortes, Md.S.R., Dantas, E.H.M.(2010). "Plasma levels of leptin in overweight adults undergoing concurrent training". ISMJ., Vol. 11, No. 3, PP: 356-362.
32. Ryan, A.S., Praley, R.E., Goldberg, A.P. (2000). "Changes in plasma leptin and insulin action with resistive training in postmenopausal females. International Journal of Obesity and Relation". Metabolic Disorders., Vol. 24, PP: 27-32.
33. Simon, E.M., Urruca, I., Fernandez, A., Portillo, M.P. (2006). "Trans -10,cis -12 conjugated linoleic acid prevents adiposity but not insulin resistance induced by an atherogenic diet in hamsters". JNutr Biochem., Vol. 17, No. 2, PP: 126-31.
34. Smedman, A., Vessby, B. (2001). "Conjugated linoleic acid supplementation in humans--metabolic effects". Lipids., Vol .36, PP: 773– 81.
35. Steck, S.E., Chalecki, A.M., Miller, P., Conway, J., Austin, G.L., Hardin, J.W., et al. (2007). "Conjugated linoleic acid supplementation for twelve weeks increases lean body mass in obese humans". J Nutr., Vol. 137, No. 5, PP :1188-93.
36. Tarnopolsky, M., Zimmer, A., Paikin, J., Safdar, A,. Aboud, A,. Pearee, E . (2007). "Creatine monohydrate and conjugated linoleic acid improve strength and body composition following resistance exercise in older adults". PLoS ONE., Vol. 10, No. 2, PP: e991.
37. Taylor, J.S., Williams, S,R., Rhys, R., James, P., Frenneaux, M.P. (2006). "Conjugated linoleic acid impairs endothelial function". Arterioscler Thromb Vasc Biol., Vol. 26, PP: 307–12.
38. Thom, E., Wadstein, J., Gudmundsen, O. (2001). "Conjugated linoleic acid reduces body fat in healthy exercising humans". J Int Med Res., Vol. 29, PP: 392–6.
39. Wang, Y.W., Jones, P.J. (2004). "Conjugated linoleic acid and obesity control: Efficacy and mechanisms". Int J Obes Relat Metab Disord., Vol. 28No. 8, PP: 941-55.
40. Watras, A.C., Buchholz, A.C., Close, R.N., Zhang, Z., Schoeller, D,A. (2007). "The role of conjugated linoleic acid in reducingbody fat and preventing holiday weight gain". Int J Obes (Lond)., Vol. 31, PP: 481–7.
41. Whigham, L.D., Cook, M.E., Atkinson, R.L. (2000). "Conjugated linoleic acid: implications for human health". Pharmacol Res., Vol. 42, PP: 503-10.