Effects of Adding End-Range Isometric Holds to Isotonic Knee Extensor Training on Isokinetic Performance in Sedentary Adults: A Randomized Controlled Trial

The goal of this clinical trial is to learn if adding a short muscle hold (isometric contraction) to a standard leg-strengthening exercise improves knee muscle strength more than the standard exercise alone, in healthy adults who do not exercise regularly. The main question it aims to answer is: Does adding a 5-second hold at the end of each leg-extension exercise lead to greater gains in front-thigh muscle (quadriceps) strength than leg-extension exercise alone? Researchers will compare two exercise groups to see if the added muscle hold makes a difference: Group 1 will do leg-extension exercises with a 5-second hold added at the end of each repetition. Group 2 will do the same leg-extension exercises without the added hold. Participants will: Do leg-extension exercises 3 days a week for 8 weeks Have their thigh muscle strength tested before and after the program using a special exercise machine Have their thigh size measured before and after the program

Inclusion Criteria: * Age 18-40 years * Sedentary lifestyle (low physical activity level) * Healthy individuals with no known knee-related disability Exclusion Criteria: * Musculoskeletal problems of the lower extremity * History of lower extremity surgery or significant trauma * Low back pain and/or lumbar region problems * Cardiac complaints * Neurological complaints * Chronic systemic disease (e.g., diabetes mellitus, rheumatologic conditions)