Phenotype transformation toward hypersensitivity to soreness in post-exercise muscle

Acute muscle soreness and delayed onset muscle soreness (DOMS) are familiar post-exercise muscle discomforts. While DOMS is intensively investigated, the features and associated somatosensory alterations of acute muscle soreness remain less understood. To this end, thirty healthy adults underwent a strenuous wrist extension protocol targeting the left extensor carpi radialis (ECR), with the ipsilateral flexor carpi ulnaris (FCU) and contralateral ECR as control muscles. Mechanical, vibration, and pressure sensitivities were measured before and immediately after exercise. Participants qualitatively described their sensory experiences using descriptors from the McGill Pain Questionnaire. During exertion, participants predominantly identified soreness, rather than pain, as the main sensation in the exercised muscle (Lt ECR). After exercise, the exerted muscles exhibited significantly increased sensitivity to pressure (p