Changes in Drop and Repeated Jump Ground Reaction Forces After a 10-Week Offseason Strength and Conditioning Program in Division I American Football Players

The purpose of this study was to examine changes in ground reaction forces during drop jumps (DJs) and repeated jumps (RJs) across a 10-week offseason strength and conditioning program in collegiate Division I American football players. Twenty-two NCAA Division I American football players were recru...

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Main Authors: Zachary Gillen, Reuben Burch, David Saucier, Lesley Strawderman, Tony Luczak, Anthony Piroli, Adam Petway, Ted Rath
Format: Article
Language:English
Published: International Universities Strength and Conditioning Association 2025-02-01
Series:International Journal of Strength and Conditioning
Subjects:
Online Access:https://journal.iusca.org/index.php/Journal/article/view/358
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author Zachary Gillen
Reuben Burch
David Saucier
Lesley Strawderman
Tony Luczak
Anthony Piroli
Adam Petway
Ted Rath
author_facet Zachary Gillen
Reuben Burch
David Saucier
Lesley Strawderman
Tony Luczak
Anthony Piroli
Adam Petway
Ted Rath
author_sort Zachary Gillen
collection DOAJ
description The purpose of this study was to examine changes in ground reaction forces during drop jumps (DJs) and repeated jumps (RJs) across a 10-week offseason strength and conditioning program in collegiate Division I American football players. Twenty-two NCAA Division I American football players were recruited for this study, however, a total of n = 19 subjects (mean ± 95% confidence interval, height=186.83±2.66 cm, body mass=102.73±8.79 cm) completed the study. Subjects visited the laboratory twice, once for pre- and once for post-offseason testing. Subjects performed DJs and RJs during each visit. The DJ was performed off a 30 cm box. The RJ protocol consisted of four consecutive jumps. Ground reaction forces were collected during all jumps. Dependent samples t-tests compared changes in DJ metrics, while repeated measures analyses of variance compared changes in RJ metrics. For the DJ, peak braking power, peak propulsive power, mean propulsive force, and jump height increased (p≤0.027, d≥0.552). For jump 1 of the RJ, peak braking power increased (p=0.005, d=0.733). For all jumps of the RJ, peak propulsive power, mean propulsive force, jump height, and reactive strength index increased (p≤0.049, η2≥0.134). This study demonstrated that DJ and RJ performance increased in 10-weeks of strength and conditioning training. Strength and conditioning coaches may benefit from including DJ and RJ assessments to monitor the effectiveness of the strength and conditioning program.
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spelling doaj-art-b7a157110a83494f8de3ff2156a2a1f42025-02-11T20:00:27ZengInternational Universities Strength and Conditioning AssociationInternational Journal of Strength and Conditioning2634-22352025-02-015110.47206/ijsc.v5i1.358Changes in Drop and Repeated Jump Ground Reaction Forces After a 10-Week Offseason Strength and Conditioning Program in Division I American Football PlayersZachary Gillen0https://orcid.org/0000-0001-7976-6161Reuben Burch1David Saucier2Lesley Strawderman3Tony Luczak4Anthony Piroli5Adam Petway6https://orcid.org/0000-0003-2324-3868Ted Rath7Mississippi State UniversityMississippi State UniversityMississippi State UniversityMississippi State UniversityUniversity of Central OklahomaTampa Bay BuccaneersMississippi State UniversityPhiladelphia Eagles The purpose of this study was to examine changes in ground reaction forces during drop jumps (DJs) and repeated jumps (RJs) across a 10-week offseason strength and conditioning program in collegiate Division I American football players. Twenty-two NCAA Division I American football players were recruited for this study, however, a total of n = 19 subjects (mean ± 95% confidence interval, height=186.83±2.66 cm, body mass=102.73±8.79 cm) completed the study. Subjects visited the laboratory twice, once for pre- and once for post-offseason testing. Subjects performed DJs and RJs during each visit. The DJ was performed off a 30 cm box. The RJ protocol consisted of four consecutive jumps. Ground reaction forces were collected during all jumps. Dependent samples t-tests compared changes in DJ metrics, while repeated measures analyses of variance compared changes in RJ metrics. For the DJ, peak braking power, peak propulsive power, mean propulsive force, and jump height increased (p≤0.027, d≥0.552). For jump 1 of the RJ, peak braking power increased (p=0.005, d=0.733). For all jumps of the RJ, peak propulsive power, mean propulsive force, jump height, and reactive strength index increased (p≤0.049, η2≥0.134). This study demonstrated that DJ and RJ performance increased in 10-weeks of strength and conditioning training. Strength and conditioning coaches may benefit from including DJ and RJ assessments to monitor the effectiveness of the strength and conditioning program. https://journal.iusca.org/index.php/Journal/article/view/358Vertical jumpForce plateCollegiate football
spellingShingle Zachary Gillen
Reuben Burch
David Saucier
Lesley Strawderman
Tony Luczak
Anthony Piroli
Adam Petway
Ted Rath
Changes in Drop and Repeated Jump Ground Reaction Forces After a 10-Week Offseason Strength and Conditioning Program in Division I American Football Players
International Journal of Strength and Conditioning
Vertical jump
Force plate
Collegiate football
title Changes in Drop and Repeated Jump Ground Reaction Forces After a 10-Week Offseason Strength and Conditioning Program in Division I American Football Players
title_full Changes in Drop and Repeated Jump Ground Reaction Forces After a 10-Week Offseason Strength and Conditioning Program in Division I American Football Players
title_fullStr Changes in Drop and Repeated Jump Ground Reaction Forces After a 10-Week Offseason Strength and Conditioning Program in Division I American Football Players
title_full_unstemmed Changes in Drop and Repeated Jump Ground Reaction Forces After a 10-Week Offseason Strength and Conditioning Program in Division I American Football Players
title_short Changes in Drop and Repeated Jump Ground Reaction Forces After a 10-Week Offseason Strength and Conditioning Program in Division I American Football Players
title_sort changes in drop and repeated jump ground reaction forces after a 10 week offseason strength and conditioning program in division i american football players
topic Vertical jump
Force plate
Collegiate football
url https://journal.iusca.org/index.php/Journal/article/view/358
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