Collagen supplementation group will have 12 participants. They will perform various physical assessments that include pain scale, pain pressure threshold assessment, body composition, calf circumference measurements, muscle thickness measurements, Achilles tendon length and thickness measurements, myotonography of the calf, isometric force assessments during standing and seated plantarflexion positions, a heel raise test, and a standardized exercise routine focused on eccentric movements, targeting a leg chosen at random. Additionally, they will consume a daily dose of two 30-g amount of collagen peptides derived from bovine hide (commercially available as Vital Proteins or Peptan).

Placebo supplementation group will have 12 participants. They will perform various physical assessments that include pain scale, pain pressure threshold assessment, body composition, calf circumference measurements, muscle thickness measurements, Achilles tendon length and thickness measurements, myotonography of the calf, isometric force assessments during standing and seated plantarflexion positions, a heel raise test, and a standardized exercise routine focused on eccentric movements, targeting a leg chosen at random. Additionally, they will consume a daily dose of placebo (two 30 g of pure maltodextrin with no amino acids) mixed in 300 ml of orange Gatorade zero.

Control group (n=12) will receive no supplement. Control group participants will do all the assessments that the intervention participants are performing, except for the standardized exercise routine focused on the eccentric movements. Randomization will be performed via www.randomizer.org website.

Participants will consume two 30-g amount of collagen peptides derived from bovine hide (commercially available as Vital Proteins or Peptan) mixed in 300 ml of orange gatorade zero.

Portable B-mode Ultrasound (GE Logiq e BT12, GE Healthcare, Milwaukee, WI, USA) and a multi-frequency linear- array probe (12 L-RS, 5-13 MHz, 38.4-mm field of view, GE Healthcare, Milwaukee, WI, USA) will be used to determine changes in muscle thickness of the randomized leg. The distance between the medial point of the knee joint space and the central point of the medial malleolus will be measured at 70% and ultrasound gel will be placed on this location prior to measurement. The highest and mean values of 3-5 measurements will be recorded for each assessment. All measurements will be done on one randomized leg.

Achilles tendon will be scanned using a B-mode US imaging device (GE Logiq e, GE Healthcare,Wauwatosa, WI, USA) and a multi-frequency linear-array probe (12 L-RS, 5-13 MHz, 38.4-mm field of view; GE Healthcare). The same researcher will perform the assessments. All ultrasound imaging analyses will be performed using Image-J software 1.8.0 (National Institute of Health, Bethesda, MD, USA). Achilles tendon length will be determined using the segmented line function between calcaneal notch and muscle-tendon junction along the midline of the Achilles tendon. Additionally, sagittal images of the Achilles tendon will be collected with the ankle passively dorsiflexed to approximately 90 degrees. Tendon thickness will be measured at reference point of 2 cm proximal to the superior aspect of the calcaneus.