Glycogen Concentration and Bioenergetics in Young and Older Women

Anne Tonson¹, Jacob Deblois¹, Jessica Fay¹, Steve Foulis¹, Douglas E. Befroy², Jane Kent-Braun¹

The purpose of this study was to investigate muscle metabolic economy and [glycogen] in relation to ATP flux during brief voluntary contractions, using 13 C and 31P magnetic resonance spectroscopy (MRS) in young and older women. Although intramuscular fat was lower in young than older women, muscle size, specific strength, [glycogen], metabolic economy and the contributions of PCr, glycolysis and oxidative metabolism were not different by age. These results suggest that energetics do not differ in the unfatigued muscles of young and old.