Details

Autor(en) / Beteiligte

• Nielsen, Joachim
• Jensen, Rasmus
• Ørtenblad, Niels

Titel

Assessments of individual fiber glycogen and mitochondrial volume percentages reveal a graded reduction in muscle oxidative power during prolonged exhaustive exercise

Ist Teil von

• Scandinavian journal of medicine & science in sports, 2024-02, Vol.34 (2), p.e14571-n/a

Ort / Verlag

Denmark: Blackwell Publishing Ltd

Erscheinungsjahr

2024

Link zum Volltext

Quelle

Wiley-Blackwell Journals

Beschreibungen/Notizen

• During submaximal exercise, there is a heterogeneous recruitment of skeletal muscle fibers, with an ensuing heterogeneous depletion of muscle glycogen both within and between fiber types. Here, we show that the mean (95% CI) mitochondrial volume as a percentage of fiber volume of non‐glycogen‐depleted fibers was 2 (−10:6), 5 (−21:11), and 12 (−21:−2)% lower than all the sampled fibers after continuing exercise for 1, 2 h, and until task failure, respectively. Therefore, a glycogen‐dependent fatigue of individual fibers during submaximal exercise may reduce the muscular oxidative power. These findings suggest a relationship between glycogen and mitochondrial content in individual muscle fibers, which is important for understanding fatigue during prolonged exercise.