TY - JOUR

T1 - Training affects muscle phospholipid fatty acid composition in humans

AU - Helge, Jørn Wulff

AU - Wu, B J

AU - Willer, Mette

AU - Daugaard, J R

AU - Storlien, L H

AU - Kiens, B

PY - 2001/2/1

Y1 - 2001/2/1

N2 - Training improves insulin sensitivity, which in turn may affect performance by modulation of fuel availability. Insulin action, in turn, has been linked to specific patterns of muscle structural lipids in skeletal muscle. This study investigated whether regular exercise training exerts an effect on the muscle membrane phospholipid fatty acid composition in humans. Seven male subjects performed endurance training of the knee extensors of one leg for 4 wk. The other leg served as a control. Before, after 4 days, and after 4 wk, muscle biopsies were obtained from the vastus lateralis. After 4 wk, the phospholipid fatty acid contents of oleic acid 18:1(n-9) and docosahexaenoic acid 22:6(n-3) were significantly higher in the trained (10.9 +/- 0.5% and 3.2 +/- 0.4% of total fatty acids, respectively) than the untrained leg (8.8 +/- 0.5% and 2.6 +/- 0.4%, P <0.05). The ratio between n-6 and n-3 fatty acids was significantly lower in the trained (11.1 +/- 0.9) than the untrained leg (13.1 +/- 1.2, P <0.05). In contrast, training did not affect muscle triacylglycerol fatty acid composition. Citrate synthase activity was increased by 17% in the trained compared with the untrained leg (P <0.05). In this model, diet plays a minimal role, as the influence of dietary intake is similar on both legs. Regular exercise training per se influences the phospholipid fatty acid composition of muscle membranes but has no effect on the composition of fatty acids stored in triacylglycerols within the muscle.

AB - Training improves insulin sensitivity, which in turn may affect performance by modulation of fuel availability. Insulin action, in turn, has been linked to specific patterns of muscle structural lipids in skeletal muscle. This study investigated whether regular exercise training exerts an effect on the muscle membrane phospholipid fatty acid composition in humans. Seven male subjects performed endurance training of the knee extensors of one leg for 4 wk. The other leg served as a control. Before, after 4 days, and after 4 wk, muscle biopsies were obtained from the vastus lateralis. After 4 wk, the phospholipid fatty acid contents of oleic acid 18:1(n-9) and docosahexaenoic acid 22:6(n-3) were significantly higher in the trained (10.9 +/- 0.5% and 3.2 +/- 0.4% of total fatty acids, respectively) than the untrained leg (8.8 +/- 0.5% and 2.6 +/- 0.4%, P <0.05). The ratio between n-6 and n-3 fatty acids was significantly lower in the trained (11.1 +/- 0.9) than the untrained leg (13.1 +/- 1.2, P <0.05). In contrast, training did not affect muscle triacylglycerol fatty acid composition. Citrate synthase activity was increased by 17% in the trained compared with the untrained leg (P <0.05). In this model, diet plays a minimal role, as the influence of dietary intake is similar on both legs. Regular exercise training per se influences the phospholipid fatty acid composition of muscle membranes but has no effect on the composition of fatty acids stored in triacylglycerols within the muscle.

KW - Adult

KW - Docosahexaenoic Acids

KW - Energy Intake

KW - Exercise Test

KW - Fatty Acids

KW - Fatty Acids, Unsaturated

KW - Humans

KW - Male

KW - Muscle, Skeletal

KW - Oleic Acids

KW - Phospholipids

KW - Physical Endurance

KW - Triglycerides

M3 - Journal article

C2 - 11160068

VL - 90

SP - 670

EP - 677

JO - Journal of Applied Physiology

JF - Journal of Applied Physiology

SN - 8750-7587

IS - 2

ER -