This randomized, double-blind, single-center pilot clinical trial evaluated three interventions for delayed onset muscle soreness in the hamstring muscles.

Twenty-nine untrained adults were included. Delayed onset muscle soreness was induced using two eccentric hamstring exercises. Participants were then assigned to one of three groups: proprioceptive neuromuscular facilitation, local cryotherapy, or placebo consisting of water with sugar.

The main outcome was pressure pain threshold in the hamstring muscles. Other outcomes included knee range of motion, hamstring strength, pain intensity, perceived exertion, and blood lactate levels. Measurements were taken before the eccentric exercise, 24 hours after exercise before treatment, immediately after treatment, and 48 hours after exercise.

Inclusion Criteria:

• Adults aged between 18 and 45 years.
• Participants who did not usually perform physical exercise or whose exercise was not focused on the lower limbs.
• Participants who had previously experienced delayed onset muscle soreness and were familiar with its effects.

Exclusion Criteria:

• Musculoskeletal injury of the lower limb.
• Pregnancy.
• Diabetes.
• Cardiovascular problems.
• History of cancer.
• Autoimmune diseases, including Raynaud disease or rheumatoid arthritis.
• Sensory disorders.
• Skin disorders.
• Skin conditions.
• Peripheral venous or lymphatic vascular insufficiency.

De-identified individual participant data related to the outcomes reported in the study may be shared upon reasonable request to the principal investigator. Data will only be shared for academic and research purposes, after approval by the study team, and in accordance with applicable data protection regulations.

Participants and outcome assessors were masked to group allocation. Group assignment was concealed using opaque envelopes, and only the investigator responsible for administering the active intervention knew the allocated treatment.