The Effectiveness of Sustained Heat Treatment on Delayed-Onset Muscle Soreness (DOMS)

Inclusion Criteria: * Any gender and any ethnic origin, aged between 18 and 55 years (inclusive), in good general health and able to perform and complete the exercise regimen. * No significant physical activity causing DOMS in the thighs/quads in the past 4 weeks. Body mass index \<40 kg/m2. * No clinically relevant cardiovascular disease, hepatic disease, diabetes, lower limb neuropathies or recent lower limb injuries. * Normal blood pressure (systolic blood pressure 90 to 140 mmHg, diastolic blood pressure 60 to 90 mmHg, inclusive) at rest. * Subject is either not of childbearing potential (defined as biological male sex or postmenopausal for at least 1 year or surgically sterile \[bilateral tubal ligation, bilateral oophorectomy, or hysterectomy\]) and must agree not to start a pregnancy from the signature of the informed consent up to the final visit or practicing one of the following medically acceptable methods of birth control: 1. Hormonal methods such as oral, implantable, injectable, or transdermal contraceptives for a minimum of 1 full cycle (based on the subject's usual menstrual cycle period) up to the final visit 2. Total abstinence from sexual intercourse since the last menses before exposure to the device and up to the final visit 3. Intrauterine device 4. Double-barrier method (condoms, sponge, diaphragm, with spermicidal jellies or cream) up to the final visit -----Must have personal smartphone (i.e., iOS or Android). * Capable of returning to the investigation center for all the visits according to requirement of CIP. * Willing to comply with the policy, procedure, and restriction of the investigation. * Capable of actively communicating with the investigator. * Capable of completing the investigation-related documents. * Capable of understanding the contents of the informed consent and personal data processing consent and legally ---capable of signing a written informed consent and a personal data processing consent prior to any investigation-related procedures. Exclusion Criteria: * Skin lesions (e.g., rash, bruising, laceration) in the thigh region, or spreading skin conditions (e.g., poison ivy, urticaria) in other regions, or any skin abnormality likely to be aggravated by the device such as dermatological disease or infection, rash, atrophic, fragile or abnormally dry skin, cuts or abrasions at the treatment site. * Clinically significant abnormalities at medical history and/or physical examination at Visit 1, which in the opinion of the investigator could interfere with the investigation procedures or endpoint evaluations. * Treatment with alpha or beta agonists/antagonists, any type of anti-inflammatory or analgesic medications, Cox-2 inhibitors, calcium channel blockers, pregabalin (Lyrica), other pain reducers, muscle relaxants, creatine, ephedrine or pseudoephedrine. * Lactating or pregnant women. * Suspected or confirmed coronavirus disease 2019 infection at Visit 1. * History of (within the past 12 months) or current alcohol or substance abuse. * Any history of radiculopathy and neurological deficits. * Vulnerable subjects (i.e., individuals who are unable to fully understand all aspects of the investigation that are relevant to the decision to participate, or who could be manipulated or unduly influenced as a result of a compromised position, expectation of benefits or fear of retaliatory response). * Subjects who have participated in another interventional investigation within the past 30 days before enrollment or are currently participating in another non-interventional investigation which might impact the outcome of this investigation. * Subjects who are involved in the conduct of the investigation (i.e., investigator or his/her deputy, first grade relatives, pharmacist, assistant or other personnel). * Known skin hypersensitivity to adhesion products. * Any other condition that, in the opinion of the investigator, interferes with the investigation endpoints/procedures and does not justify the inclusion of the subject in the investigation.