Intramyocellular lipid changes in men and women during aerobic exercise: a (1)H-magnetic resonance spectroscopy study.
This study was designed to compare intramyocellular lipid (IMCL) changes during 60 min of submaximal exercise in men and women. Eighteen moderately active (18-38 yr) men (n = 9) and women (n = 9) were recruited. Maximum oxygen consumption (O(2)max) and body composition were used to match subjects for aerobic fitness and body composition. Subjects performed cycle ergometry for 1 h at 65% of O(2)max. Expired gases were collected throughout exercise to determine caloric expenditure and substrate use. Blood samples were collected before and after exercise to evaluate markers of lipid metabolism. Pre- and postexercise proton spectra were acquired from the vastus lateralis using a 3-T whole-body imaging system. Spectra were acquired from an 18-mm(3) region of interest (echo time = 45 msec; repetition time = 2000 msec) for IMCL evaluation. IMCL decreased significantly with exercise (11.5-28.5% for men and 17.1-21.7% for women) (P < 0.05); however, there were no significant differences between men and women. Although changes were found for many plasma variables [free fatty acids, glycerol, and norepinephrine (P < 0.05)], group differences were only evident for norepinephrine. In conclusion, a significant decrease in IMCL was observed during 60 min of cycling in matched men and women.
White
Lesley J
LJ
Departments of Exercise and Sport Sciences, University of Florida, Gainesville, Florida 32611, USA. white@hhp.ufl.edu
Ferguson
Michael A
MA
McCoy
Sean C
SC
Kim
HeeWon
H
D000328:Adult; D004734:Energy Metabolism; D015444:Exercise / Q000502:physiology*; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005260:Female; D005990:Glycerol / Q000097:blood; D006728:Hormones / Q000097:blood; D006801:Humans; D050356:Lipid Metabolism; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D018482:Muscle, Skeletal / Q000166:cytology / Q000378:metabolism*; D010101:Oxygen Consumption; D011522:Protons; D012727:Sex Characteristics; D014280:Triglycerides / Q000097:blood
D005230:Fatty Acids, Nonesterified; D006728:Hormones; D011522:Protons; D014280:Triglycerides; D005990:Glycerol