Acute and chronic exercise in patients with heart failure with reduced ejection fraction: evidence of structural and functional plasticity and intact angiogenic signalling in skeletal muscle.

Key Points: The vascular endothelial growth factor (VEGF) responses to acute submaximal exercise and training effects in patients with heart failure with reduced ejection fraction (HFrEF) were investigated. Six patients and six healthy matched controls performed knee-extensor exercise (KE) at 50% of maximum work rate before and after (only patients) KE training. Muscle biopsies were taken to assess skeletal muscle structure and the angiogenic response.

Sedentary aging increases resting and exercise-induced intramuscular free radical formation.

Mitochondrial free radical formation has been implicated as a potential mechanism underlying degenerative senescence, although human data are lacking. Therefore, the present study was designed to examine if resting and exercise-induced intramuscular free radical-mediated lipid peroxidation is indeed increased across the spectrum of sedentary aging. Biopsies were obtained from the vastus lateralis in six young (26 + or - 6 yr) and six aged (71 + or - 6 yr) sedentary males at rest and after maximal knee extensor exercise.

Limited maximal exercise capacity in patients with chronic heart failure: partitioning the contributors.

Objectives: This study aimed to assess the factors limiting maximal exercise capacity in patients with chronic heart failure (CHF).

Background: Maximal exercise capacity, an important index of health in CHF, might be limited by central and/or peripheral factors; however, their contributions remain poorly understood.

Methods: We studied oxygen (O2) transport and metabolism at maximal cycle (centrally taxing) and knee-extensor (KE) (peripherally taxing) exercise in 12 patients with CHF and 8 healthy control subjects in normoxia and hyperoxia (100% O2).

The skeletal muscle VEGF mRNA response to acute exercise in patients with chronic heart failure.

In seven patients with chronic heart failure (CHF) and six controls, we examined (a) resting and post-exercise muscle vascular endothelial growth factor (VEGF) mRNA levels and (b) their relationship with muscle structure and function. Muscle biopsies were taken after 30 min of single-leg knee-extensor exercise at 50% of maximum work rate (50% WR(max)) from both the exercised and rested legs. Muscle blood flow (.

Electron paramagnetic spectroscopic evidence of exercise-induced free radical accumulation in human skeletal muscle.

The present study determined if acute exercise increased free radical formation in human skeletal muscle. Vastus lateralis biopsies were obtained in a randomized balanced order from six males at rest and following single-leg knee extensor exercise performed for 2 min at 50% of maximal work rate (WR(MAX)) and 3 min at 100% WR(MAX). EPR spectroscopy revealed an exercise-induced increase in mitochondrial ubisemiquinone (UQ*-) [0.