The effects of conjugated linoleic acid supplementation during resistance training.
OBJECTIVE
We determined the effects of conjugated linoleic acid (CLA) supplementation during resistance training.


METHODS
Seventy-six subjects were randomized to receive CLA (5 g.d(-1)) or placebo (PLA) for 7 wk while resistance training 3 d.wk(-1). Seventeen subjects crossed over to the opposite group for an additional 7 wk. Measurements at baseline, 7 wk, and 14 wk (for subjects in the crossover study) included body composition, muscle thickness of the elbow flexors and knee extensors, resting metabolic rate (RMR), bench and leg press strength, knee extension torque, and urinary markers of myofibrillar degradation (3-methylhistidine (3MH) and bone resorption (cross-linked N-telopeptides (Ntx)).


RESULTS
After 7 wk the CLA group had greater increases in lean tissue mass (LTM) (+1.4 vs +0.2 kg; P < 0.05), greater losses of fat mass (-0.8 vs +0.4 kg; P < 0.05), and a smaller increase in 3MH (-0.1 vs + 1.3 micromol.kg LTM.d(-1); P < 0.05) compared with PLA. Changes between groups were similar for all other measurements, except for a greater increase in bench press strength for males on CLA (P < 0.05). In the crossover study subjects had minimal changes in body composition, but smaller increases in 3MH (-1.2 vs +2.2 micromol.kg LTM.d(-1); P < 0.01) and NTx (-4.8 vs +7.3 nmol.kg(-1) LTM.d(-1); P < 0.01) while on CLA versus PLA.


CONCLUSIONS
Supplementation with CLA during resistance training results in relatively small changes in body composition accompanied by a lessening of the catabolic effect of training on muscle protein.
College of Kinesiology, University of Saskatchewan, Saskatoon, Canada.
Craig
C
Pinkoski
Philip D
PD
Chilibeck
Darren G
DG
Candow
Dale
D
Esliger
Julia B
JB
Ewaschuk
Marina
M
Facci
Jonathan P
JP
Farthing
Gordon A
GA
Zello
D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001481:Basal Metabolism; D001823:Body Composition; D024042:Collagen Type I / Q000652:urine; D018592:Cross-Over Studies; D005260:Female; D006801:Humans; D044243:Linoleic Acids, Conjugated / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D008762:Methylhistidines / Q000652:urine; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000502:physiology; D010455:Peptides / Q000652:urine; D010806:Physical Education and Training; D011795:Surveys and Questionnaires; D019415:Torque; D016896:Treatment Outcome
D024042:Collagen Type I; D044243:Linoleic Acids, Conjugated; D008762:Methylhistidines; D010455:Peptides; C052929:collagen type I trimeric cross-linked peptide; C028118:3-methylhistidine