Effects of physical exercise on phospholipid fatty acid composition
in skeletal muscle.
Andersson, Agneta, Anders Sj[diaeresis]odin, Roger Olsson, and Bengt
Vessby.
Departments of Geriatrics and Nutrition, Uppsala University, and
PhysTest Scandinavia AB, S-751 25 Uppsala, Sweden
APStracts 4:0256E, 1997.
The effects of low-intensity exercise on the fatty acid composition in
skeletal muscle and in serum were studied in 19 sedentary, middle
-aged Swedish men. During a ten-week period all subjects were given a
standardized diet with an identical fat composition. After four weeks
on this diet they were randomly allocated to a daily exercise program
(55% V02-peak) or to continue to live a sedentary life for the
remaining six weeks. Aerobic capacity (submaximal bicycle test) and
peripheral insulin sensitivity (hyperinsulinemic euglycemic clamp)
improved with training, while the body weight as well as the body
composition (underwater weighing and bioimpedance) was unchanged. The
proportions of palmitic acid (16:0) and linoleic acid (18:2 n-6) and
the sum of n-6 fatty acids (18:2 n-6, 20:3 n-6, 20:4 n-6) were
decreased in skeletal muscle phospholipids, while the proportion of
oleic acid (18:1 n-9) was increased, by training. The fatty acid
profile in skeletal muscle triglycerides remained unchanged. We
conclude that regular low-intensity exercise influence the fatty acid
composition of the phospholipids in skeletal muscle, which
hypothetically may contribute to changes of the skeletal muscle
membrane fluidity and influence the peripheral insulin sensitivity.
Received 12 May 1997; accepted in final form 11 November 1997.
APS Manuscript Number E216-7.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1997 The American Physiological Society.
Published in APStracts on 12 December 1997