Jump Rope Training and Shoulder Isokinetics in CrossFit

NCT ID: NCT06924775

Last Updated: 2025-04-11

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 18 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2022-07-30
• Study Completion Date: 2023-03-30

Brief Summary

The goal of this quasi-experimental clinical trial is to evaluate whether weighted jump rope (WJR) training can improve the isokinetic shoulder strength profile in male and female CrossFit practitioners.

The main questions it aims to answer are:

• Does six weeks of WJR training affect internal and external shoulder rotational peak torque relative to body mass?
• Does WJR influence the external/internal shoulder rotation ratio in dominant and non-dominant arms at varying angular velocities? Researchers will compare pre- and post-intervention isokinetic measurements to see if WJR training leads to significant changes in shoulder strength and balance.

Participants will:

• Incorporate WJR sessions three times per week into their usual CrossFit training.
• Undergo isokinetic testing of both shoulders at baseline and post-intervention at 60°/s, 180°/s, and 300°/s.
• Have their training adherence and technique monitored throughout the study.

Detailed Description

Model: Single Group

Model Description:

This study followed a single-arm, quasi-experimental pre-post design in which all participants underwent the same intervention: six weeks of weighted jump rope (WJR) training, integrated into their regular CrossFit routines. The intervention's impact on isokinetic shoulder strength variables was assessed by comparing pre- and post-intervention measures within the same group of participants.

Number of Arms

1, Only one group received the intervention-there was no control or comparator group.

Masking Outcomes Assessor.

Masking Description:

Due to the nature of the physical intervention (WJR training), blinding participants and care providers was not feasible. However, outcome assessors conducting the isokinetic tests were blinded to the study's hypotheses and group allocations to reduce measurement bias.

Allocation N/A. Participants were not randomly assigned but instead enrolled in a single group to undergo the same intervention protocol.

Enrollment 18 participants

Conditions

Evaluation of the Effects of Weighted Jump Rope Training on the Isokinetic Shoulder Profile in CrossFit Practitioners

Study Design

• Allocation Method: NA
• Intervention Model: SINGLE_GROUP
• Primary Study Purpose: SCREENING
• Blinding Strategy: NONE

Study Groups

Weighted jump rope training group

A progressive six-week jump rope protocol focusing on simple unders was completed three times per week, individually or in groups, before regular sessions. Training was supervised by final-year kinesiology students. Based on Duzgun et al. (2010), jumps increased weekly: Week 1-D1: 6×25, D2: 3×50, D3: 4×50 (500 total); Week 2-4×50, 4×75, 4×50 (750); Week 3-4×75, 4×75, 4×100 (1000); Week 4-6×75, 6×75, 5×70 (1250); Week 5-5×100, 4×150, 4×100 (1500); Week 6-5×150, 6×100, 4×100 (1750). Rest between sets: 1 min. Participants were advised to avoid prior intense activity, maintain steady pace, and received positive reinforcement as needed.

Group Type: EXPERIMENTAL

Weighted jump rope training

Intervention Type: OTHER

Unlike isolated jump rope studies, this intervention was embedded within the participants' habitual CrossFit routine, enhancing ecological validity. Performing the jump rope protocol immediately prior to regular training-rather than as a stand-alone session-was intended to promote warm-up and neuromuscular priming benefits. The use of a weighted rope introduced a resistance stimulus that is rarely incorporated in jump rope interventions.

Interventions

Weighted jump rope training

Unlike isolated jump rope studies, this intervention was embedded within the participants' habitual CrossFit routine, enhancing ecological validity. Performing the jump rope protocol immediately prior to regular training-rather than as a stand-alone session-was intended to promote warm-up and neuromuscular priming benefits. The use of a weighted rope introduced a resistance stimulus that is rarely incorporated in jump rope interventions.

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

• self-reported CrossFit training experience. Accordingly, participants were classified into one of three categories (Torres-Banduc et al., 2021): advanced level (≥36 months of regular training, defined as ≥3 sessions of ≥120 minutes per week); intermediate level (12 to <36 months); and beginner level (6 to <12 months).
• no injuries in the three months preceding the study.

Exclusion Criteria

• musculoskeletal issues impacting muscle strength or the ability to undergo isokinetic shoulder evaluation.
• self-reported use of anabolic steroids or other prohibited substances that might influence the study results.

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

University of Americas

OTHER

Sponsor Role: lead

Responsible Party

Maximiliano Torres-Banduc

PhD.

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Maximiliano A. Torres-Banduc, PhD.

Role: PRINCIPAL_INVESTIGATOR

University of Americas

Locations

Human Movement Analysis Laboratory

Viña del Mar, V región/Valparaíso, Chile

Countries

Chile

References

Torres-Banduc MA, Jerez-Mayorga D, Moran J, Keogh JWL, Ramirez-Campillo R. Isokinetic force-power profile of the shoulder joint in males participating in CrossFit training and competing at different levels. PeerJ. 2021 Sep 17;9:e11643. doi: 10.7717/peerj.11643. eCollection 2021.

Reference Type: BACKGROUND

PMID: 34616590 (View on PubMed)

Duzgun I, Baltaci G, Colakoglu F, Tunay VB, Ozer D. The effects of jump-rope training on shoulder isokinetic strength in adolescent volleyball players. J Sport Rehabil. 2010 May;19(2):184-99. doi: 10.1123/jsr.19.2.184.

Reference Type: BACKGROUND

PMID: 20543219 (View on PubMed)

Other Identifiers

23/2022

Identifier Type: -

Identifier Source: org_study_id