Anne Tonson1, Jacob Deblois1, Jessica Fay1, Steve Foulis1, Douglas E. Befroy2, Jane Kent-Braun1
1Department of Kinesiology, University of Massachusetts, Amherst, MA, United States; 2Magnetic Resonance Research Center, Yale University, New Haven, CT, United States
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.