Effects of Heavy Back-Squat PAPE on Jump and Repeated Sprint Performance in Trained Soccer Players

Istanbul University - Cerrahpasa20 enrolled

Overview

This study examined whether performing heavy back squats before exercise affects jumping ability and repeated sprint performance in trained soccer players. Twenty male university soccer players completed two testing sessions in a randomized crossover design. In one session, participants performed a standardized warm-up only. In the other session, they performed the same warm-up followed by three sets of three back-squat repetitions at 90% of their one-repetition maximum. The two sessions were separated by one week. After each condition, participants completed a countermovement jump test and an 18 × 40-meter repeated sprint test. The study aimed to determine whether the heavy back-squat activity improves early explosive performance and whether it increases fatigue during prolonged repeated sprint exercise.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

SINGLE

Enrollment

Conditions

Post-activation Performance Enhancement and Repeated Sprint Performance in Trained Soccer Players

Interventions

Participants completed a standardized warm-up followed by a heavy back-squat conditioning activity consisting of three sets of three repetitions at 90% of one-repetition maximum. Three minutes of passive recovery were provided between sets. Countermovement jump performance was assessed approximately 4.5-5 minutes after the final squat set, immediately before the repeated sprint test.

Standardized Warm-Up Control ConditionBEHAVIORAL

Participants completed a standardized warm-up consisting of 5 minutes of jogging, followed by 10 bodyweight squats, 10 lunges, and 10 lateral shuffles. No additional conditioning activity was performed. After approximately 5 minutes of passive recovery, countermovement jump performance was assessed immediately before the repeated sprint test.

Eligibility

Sex: MALEMin age: 20 YearsMax age: 23 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * Male soccer players aged 20-23 years. * Currently competing in the top division of a university soccer league. * A minimum of three years of regular soccer training experience. * Free from long-term musculoskeletal injury during the previous six months. * Willing and able to complete all familiarization, strength-testing, and experimental sessions. * Provision of written informed consent. Exclusion Criteria: * A musculoskeletal injury resulting in an absence from training or competition for 21 days or longer during the previous six months. * Use of medications or nutritional or ergogenic supplements that could affect exercise performance. * Any health or physical condition preventing safe participation in heavy back-squat, countermovement jump, or repeated sprint testing. * Failure to complete both experimental conditions.

Outcomes

Primary Outcomes

Repeated Sprint Performance Decrement

Percentage decline in repeated sprint performance calculated from sprint times recorded during an 18 × 40-meter shuttle sprint test. The protocol consisted of three sets of six 40-meter shuttle sprints, with 20 seconds of passive recovery between sprints and 4 minutes of passive recovery between sets. Lower percentage values indicate better maintenance of sprint performance and less fatigue.

Time frame: During the 18 × 40-meter repeated sprint test, which lasted approximately 15 minutes and was completed within each of two experimental sessions lasting approximately 25-35 minutes; the sessions were separated by a 1-week washout period.

Countermovement Jump Height

Maximum countermovement jump height measured in centimeters using the Optojump Next optical measurement system. Participants performed three maximal countermovement jump trials with their hands positioned on their hips and 60 seconds of passive recovery between trials. The highest jump height was used for analysis. Higher values indicate better jump performance.

Time frame: At approximately 5 minutes after the assigned condition, within each of two experimental sessions lasting approximately 25-35 minutes; the sessions were separated by a 1-week washout period.

Secondary Outcomes

Mean Repeated Sprint Time

Mean sprint time, measured in seconds, calculated across all 18 repetitions of the 40-meter shuttle sprint test. Sprint times were recorded using a photocell timing system. Lower values indicate better repeated sprint performance.

Best Sprint Time

The fastest sprint time, measured in seconds, recorded among the 18 repetitions of the 40-meter shuttle sprint test using a photocell timing system. Lower values indicate better sprint performance.

Worst Sprint Time

The slowest sprint time, measured in seconds, recorded among the 18 repetitions of the 40-meter shuttle sprint test using a photocell timing system. Lower values indicate better sprint performance.

Sprint Time Across Individual Repetitions

Sprint time, measured in seconds, for each of the 18 individual 40-meter shuttle sprint repetitions. Sprint-by-sprint values were used to evaluate changes in performance during the early repetitions (sprints 1-3), middle repetitions (sprints 4-8), and later repetitions (sprints 9-18). Lower values indicate faster sprint performance.

Time frame: During each repetition of the 18 × 40-meter repeated sprint test, which lasted approximately 15 minutes and was completed within each of two experimental sessions lasting approximately 25-35 minutes; the sessions were separated by a 1-week washout period