caa a22 4500 467941246 CHVBK 20180406153013.0 cr unu---uuuuu 170328e20060301xx s 000 0 eng 10.1007/s00421-005-0118-0 doi (NATIONALLICENCE)springer-10.1007/s00421-005-0118-0 Intramyocellular lipid and glycogen content are reduced following resistance exercise in untrained healthy males [Elektronische Daten] [René Koopman, Ralph Manders, Richard Jonkers, Gabby Hul, Harm Kuipers, Luc van Loon] Resistance exercise has recently been shown to improve whole-body insulin sensitivity in healthy males. Whether this is accompanied by an exercise-induced decline in skeletal muscle glycogen and/or lipid content remains to be established. In the present study, we determined fibre-type-specific changes in skeletal muscle substrate content following a single resistance exercise session. After an overnight fast, eight untrained healthy lean males participated in a ~45min resistance exercise session. Muscle biopsies were collected before, following cessation of exercise, and after 30 and 120min of post-exercise recovery. Subjects remained fasted throughout the test. Conventional light and (immuno)fluorescence microscopy were applied to assess fibre-type-specific changes in intramyocellular triacylglycerol (IMTG) and glycogen content. A significant 27±7% net decline in IMTG content was observed in the type I muscle fibres (P<0.05), with no net changes in the type IIa and IIx fibres. Muscle glycogen content decreased with 23±6, 40±7 and 44±7% in the type I, IIa and IIx muscle fibres, respectively (P<0.05). Fibre-type-specific changes in intramyocellular lipid and/or glycogen content correlated well with muscle fibre-type oxidative capacity. During post-exercise recovery, type I muscle fibre lipid content returned to pre-exercise levels within 120min. No changes in muscle glycogen content were observed during recovery. We conclude that intramyocellular lipid and glycogen stores are readily used during resistance exercise and this is likely associated with the reported increase in whole-body insulin sensitivity following resistance exercise. Springer-Verlag, 2005 Carbohydrate nationallicence IMTG nationallicence Skeletal muscle nationallicence Metabolism nationallicence Oxidative capacity nationallicence Koopman René Department of Human Biology, Maastricht University, P.O. Box 616, 6200, Maastricht, The Netherlands aut Manders Ralph Department of Human Biology, Maastricht University, P.O. Box 616, 6200, Maastricht, The Netherlands aut Jonkers Richard Department of Human Biology, Maastricht University, P.O. Box 616, 6200, Maastricht, The Netherlands aut Hul Gabby Department of Human Biology, Maastricht University, P.O. Box 616, 6200, Maastricht, The Netherlands aut Kuipers Harm Department of Movement Sciences, Nutrition Research Institute Maastricht (NUTRIM), Maastricht University, Maastricht, The Netherlands aut van Loon Luc Department of Human Biology, Maastricht University, P.O. Box 616, 6200, Maastricht, The Netherlands aut European Journal of Applied Physiology Springer-Verlag 96/5(2006-03-01), 525-534 1439-6319 96:5<525 2006 96 421 https://doi.org/10.1007/s00421-005-0118-0 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00421-005-0118-0 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Koopman René Department of Human Biology, Maastricht University, P.O. Box 616, 6200, Maastricht, The Netherlands aut NATIONALLICENCE 700 1- Manders Ralph Department of Human Biology, Maastricht University, P.O. Box 616, 6200, Maastricht, The Netherlands aut NATIONALLICENCE 700 1- Jonkers Richard Department of Human Biology, Maastricht University, P.O. Box 616, 6200, Maastricht, The Netherlands aut NATIONALLICENCE 700 1- Hul Gabby Department of Human Biology, Maastricht University, P.O. Box 616, 6200, Maastricht, The Netherlands aut NATIONALLICENCE 700 1- Kuipers Harm Department of Movement Sciences, Nutrition Research Institute Maastricht (NUTRIM), Maastricht University, Maastricht, The Netherlands aut NATIONALLICENCE 700 1- van Loon Luc Department of Human Biology, Maastricht University, P.O. Box 616, 6200, Maastricht, The Netherlands aut NATIONALLICENCE 773 0- European Journal of Applied Physiology Springer-Verlag 96/5(2006-03-01), 525-534 1439-6319 96:5<525 2006 96 421 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer