Monitoring muscle oxygenation after eccentric exercise-induced muscle damage using near-infrared spectroscopy

Abstract

Eccentric exercise (EE), a common type of muscular activity whereby muscles lengthen and contract simultaneously, is associated with higher levels of force but may also evoke muscle damage. We investigated the hypothesis that unaccustomed EE might impair muscle oxygenation and muscle blood flow in healthy adults. Ten healthy males performed a bout of 70 maximal eccentric contractions of the elbow flexors. Before and after EE on day 1 and over the next 6 days, maximum voluntary isometric torque (MVT), serum creatine kinase (CK), and the changes in muscle oxygen saturation, blood flow, and oxygen uptake (using near-infrared spectroscopy) within the biceps brachii were assessed. MVT decreased, whereas muscle soreness and CK increased after EE (p < 0.05). Mean resting oxygen saturation increased by 22% after acute EE, and remained elevated by 5%-9% for the following 6 days. During isometric contractions, significant decreases were observed in oxygen desaturation and re-saturation kinetics after EE and these declines were also significantly prevalent over the following 6 days. Both muscle blood flow and oxygen uptake increased significantly after acute EE, but recovered on the next day. This study revealed some prolonged alterations in muscle oxygenation at rest and during exercise after EE, which might be due to a decrease in muscle oxygen consumption, an increase in oxygen delivery, and (or) a combination of both. However, both oxygen consumption and blood flow recovered within 24 h after the eccentric exercise session, and therefore, the reason(s) for the changes in tissue oxygen saturation remain unknown.

The repeated-bout effect: influence on biceps brachii oxygenation and myoelectrical activity

“…6). This finding contrasts the study by Ahmadi et al (1), who reported that biceps brachii oxygenation was reduced compared with preexercise levels during a sustained isometric task at 50% of preexercise MVC for 4 days after eccentric exercise. The difference in the duration and intensity of the sustained isometric task between the Ahmadi et al study (20 s at 50% MVC) and the present study (10 s at 30% MVC) might be a reason for the discrepancy in biceps brachii oxygenation results.…”

“…Ahmadi et al (1) reported smaller changes in biceps brachii oxygenation compared with preexercise levels during a sustained isometric task at 80% MVC for 1 day after eccentric exercise of the elbow flexors. The present study and our previous study (23) using 100% MVC instead of 80% MVC confirmed their findings.…”

“…Previous studies (1,9,23) utilized NIRS to monitor changes in muscle oxygenation during a standardized exercise task following a single eccentric exercise bout. Ahmadi et al (1) reported a 30 -40% reduction in biceps brachii oxygenation during sustained isometric contraction tasks at 50% of the preexercise MVC and 80% MVC over 6 days following maximal eccentric exercise of the elbow flexors.…”

“…Ahmadi et al (1) reported a 30 -40% reduction in biceps brachii oxygenation during sustained isometric contraction tasks at 50% of the preexercise MVC and 80% MVC over 6 days following maximal eccentric exercise of the elbow flexors. Davies et al (9) showed a slower rate of decrease in vastus lateralis oxygenation during the initial 20-s transition from baseline to nearmaximal cycling intensity 2 days after eccentric squat exercise.…”

Mechanism and implications of hyperpnea exaggeration at the onset of exercise in mechanical hyperalgesia after eccentric exercise

“…that ECC-induced mitochondrial disturbances decrease muscle O2 utilization 75) . On the other hand, by evaluating muscle deoxygenation kinetics assessed with nearinfrared spectroscopy (NIRS) (For detailed information on the relationship between NIRS and V ・ O2 kinetics, see…”