Velocity-Based vs Percentage-Based Strength Training in Young Football Players

In the CMJ test, the vertical jump distance was determined with an Infinitek (Infinitek Company, Istanbul, Turkey) electronic vertical jump device. The subject performed two trials with a 60-second passive rest interval. The better result was recorded

A wireless 2-door Sinar (Turkey) brand photocell device was used to measure the subjects' 20-meter speed. The subjects ran 20m sprints twice with a 3-minute interval, and the better time was recorded. Walk forward naturally, arm relaxed and postüre tall 3 m before timing line. After final step before the line subject accelerated.

Aerobic capacity was determined by Yo-Yo IR2. In this test, participants perform 2x20-meter shuttle runs at gradually increasing speeds, moving forward and backwards between starting, turning, and finishing lines. Between each shuttle run, there is a 10-second active recovery period of walking or jogging within a 5-meter area. The running speed during the test is determined by alert sounds automatically controlled from a CD player. Cones are used to mark 2 m-wide, 20 m-long running lanes. Each lane has another cone placed 5 m behind the starting line, which indicates the active recovery zone. The test ends when the athlete's strength runs out or when they fail to reach the finish line twice, and the total distance run in the test (including the final shuttle run that is not completed) is calculated as the test result. Total covered distance was measured in this test. VO2max = distance (m) * 0.0136 + 45.3

TRD 1-RM Squat was determined using the traditional percentage method. Before the athletes began the test, their coach determined the appropriate weight for them. It was recommended that athletes start with lower weights for anatom

1-RM Squat VBT was measured weekly using an Apple iPhone 7 Plus - iOS 12.4.1 (Apple, Inc., USA) via the My Lift application (My Jump Lab, Spain). Before the athlete began the exercises, a command was given to start the movements. The requested movement (Squat) was uploaded to the Apple phone and recorded. The range of motion for the participants during the squat was measured in meters. In the squat exercise, participants were asked to squat with their knees at 90° of flexion, then immediately return to the starting position (knee and hip joints in full extension).

1-RM Bench press VBT was measured weekly using an Apple iPhone 7 Plus - iOS 12.4.1 (Apple, Inc., USA) via the My Lift application (My Jump Lab, Spain). Before the athlete began the exercises, a command was given to start the movements. The requested movement (bench press) was uploaded to the Apple phone and recorded. The range of motion for the participants during the bench press was measured in meters. In the bench press exercise, participants were asked to lowering the bar up to chest, then immediately return to the starting position (elbow in full extension). Before starting the speed-based strength training measurement the distance from the centre of the bar to participants's chest, and entered this information into the My Lift app program as requested.