Metabolic, Respiratory, and Muscle Oxygenation Responses to Sub-maximal Eccentric and Concentric Isokinetic Exercise to Exhaustion

This study aims to measure and compare the metabolic response during sub maximal eccentric and concentric isokinetic exercise performed to exhaustion. Fourteen healthy female participants in the early phase of the menstrual cycle will perform concentric exercise with one lower limb and eccentric exercise with the contralateral limb. The assignment of exercise mode to limb and the order of testing will be randomized. The exercise protocol will consist of repeated knee extensor contractions on an isokinetic dynamometer for 10 minutes at 40% of maximal torque, followed by exercise at 70% of maximal torque until exhaustion. Oxygen consumption and respiratory quotient and will be measured continuously throughout exercise using open-circuit spirometry. Muscle oxygenation will be measured also continuously using near infrared spectroscopy. Lactate and pH concentration will be measured at frequent time points during the exercise to exhaustion.

NCT Number	NCT07548333
Lead Sponsor	National and Kapodistrian University of Athens
Conditions	Eccentric Exercise, Isokinetic Test
Enrollment	14 participants
Start Date	2025-09-12
Primary Completion	2026-01-18 (estimated)
Study Completion	2026-03-28 (estimated)
Updated on ClinicalTrials.gov	2026-04-30