Resumen de Conjugated Linoleic Acid Combined With Creatine Monohydrate and Whey Protein Supplementation During Strength Training
Stephen M. Cornish, Darren G. Candow, Nathan T. Jantz, Philip D. Chilibeck, Jonathan P. Little, Scott C. Forbes, Saman Abeysekara, Gordon A. Zello
Purpose: The authors examined the combined effects of conjugated linoleic acid (CLA), creatine (C), and whey protein (P) supplementation during strength training. Methods: Sixty-nine participants (52 men, 17 women; M ± SD age 22.5 ±2.5 yr) were randomly assigned (double-blind) to 1 of 3 groups: CCP (6 g/d CLA + 9 g/d C + 36 g/d P; n = 22), CP (C + P + placebo oil; n = 25), or P (P + placebo oil; n = 22) during 5 wk of strength training (4�5 sets, 6�12 repetitions, 6 d/wk). Measurements were taken for body composition (air-displacement plethysmography), muscle thickness (ultrasound) of the flexors and extensors of the elbow and knee, 1-repetition-maximum (1-RM) strength (leg press and bench press), urinary markers of bone resorption (N-telopeptides, NTx), myofibrillar protein catabolism (3-methylhistidine; 3-MH), oxidative stress (8-isoprostanes), and kidney function (microalbumin) before and after training. Results: Contrast analyses indicated that the CCP group had a greater increase in bench-press (16.2% ± 11.3% vs. 9.7% ± 17.0%; p < .05) and leg-press (13.1% ± 9.9% vs. 7.7% ±14.2%; p < .05) strength and lean-tissue mass (2.4% ± 2.8% vs. 1.3% ±4.1%; p < .05) than the other groups combined. All groups increased muscle thickness over time (p < .05). The relative change in 3-MH (CCP �4.7% ± 70.2%, CP �0.4% ± 81.4%, P 20.3% ± 75.2%) was less in the groups receiving creatine (p < .05), with the difference for NTx also close to significance (p = .055; CCP �3.4% ± 66.6%, CP �3.9% ± 64.9%, P 26.0% ± 63.8%). There were no changes in oxidative stress or kidney function. Conclusion: Combining C, CLA, and P was beneficial for increasing strength and lean-tissue mass during heavy resistance training.
