Acute Effects Of Dumbbell Exercise On Oxygenated Hemodynamic Concentration Of Cerebral Activation: A Fnirs Study

Abstract

PURPOSE: To examine cerebral cortical activation in the reigns of the prefrontal cortex and parietal lobe during the performance of two types of dumbbell exercise. METHODS: A total of 22 young healthy male adults (mean age = 23.8 ± 2.05 years, height = 1.75 ± 0.06m, weight = 71.4 ± 8.80kg) participated in a crossover design study that involved two experimental exercise conditions: momentum dumbbell and conventional dumbbell. Participants’ task performance included 10 10-second sets of single-arm dumbbell exercise, with a rest interval of 60 seconds between sets and a 5-minute washout period between conditions. Primary outcome was oxygenated hemoglobin (HbO2) concentration in the prefrontal cortex and parietal lobe assessed with functional near-infrared spectroscopy. Secondary outcome measures were upper-limb muscle activation measured by surface electromyography. Outcome data were ascertained during exercise. RESULTS: A significant difference in HbO2 was observed in the prefrontal and parietal regions with a high level of brain activation observed during the momentum dumbbell exercise relative to the conventional dumbbell exercise (p<0.05). Compared to conventional dumbbell exercise, momentum dumbbell exercise also showed a higher level of muscle activation in the anterior deltoid and posterior deltoid of the upper arm and in the flexor carpi radialis and extensor carpi radialis longus of the forearm (p<0.05). No between-condition differences were found, however, in biceps brachii and triceps brachii (p>0.05). CONCLUSION: A dynamic dumbbell exercise, compared with a conventional dumbbell exercise, resulted in higher hemodynamic responses and greater upper-limb muscle activation in young healthy adults. The new resistance-based training exercise may be suited as a stand-alone exercise modality aimed at promoting brain health. Supported by the Shanghai City Committee of Science and Technology Key Project (17080503200) and National Natural Science Foundation of China (31701041).