Microcurrent Therapy and the Post-Exercise Physiological Response (MENS_PE)

The goal of this clinical trial is to find out whether microcurrent therapy changes blood levels of creatine kinase, a marker of muscle stress, during the first 48 hours after exercise in military personnel. The main question is: Do creatine kinase levels after exercise differ between people who receive active microcurrent therapy and those who receive a sham treatment? Twenty participants will complete a standardized exercise session. Participants will be randomly assigned to one of two groups: 10 will use an active microcurrent device, and 10 will use a sham device for the same period after exercise. The sham device looks and lights up like the active device but delivers no microcurrents. Researchers will measure creatine kinase before exercise and 24 and 48 hours afterward, then compare how levels change in the two groups. Investigators will also measure blood lactate and perceived effort shortly after exercise, before either device is applied. Participants will report any difficulties using the device, discomfort, effects on sleep or rest, and unwanted effects.

Inclusion Criteria: * Age between 18 and 45 years. * Active-duty military personnel. * Healthy volunteers with current medical clearance. * Skin over the quadriceps free of lesions, burns, or irritation. * Availability and willingness to comply with the proposed intervention protocol. * Informed consent form read and signed. Exclusion Criteria: * Implanted electronic devices: pacemakers, defibrillators, neurostimulators, etc. * Neuromuscular disease or peripheral neuropathy. * Treatment for HIV or chronic viral infections. * Uncontrolled seizure disorders (active epilepsy). * Uncontrolled, clinically significant heart disease. * Depression. * Uncontrolled hypertension. * Thrombosis. * Diabetes with neuropathy or impaired wound healing. * Active neoplasms or suspected cancer. * Recent musculoskeletal injuries (within the past three months) or chronic muscle pain in a lower limb. * Recent major surgery. * A dermatological condition in the quadriceps region. * Prescription of medications that may confound pain assessment during the seven days before or during the intervention, including nonsteroidal anti-inflammatory drugs (NSAIDs), muscle relaxants, and systemic corticosteroids. * Long-term treatment for hypercholesterolemia. * Prescription of antipsychotic or neuroleptic medications. * Long-term treatment for hypertriglyceridemia. * Alcohol or other substance abuse. * Inability to follow the intervention instructions.