Multimodal Exercises on Sprint Performance of Rugby Players

Study Overview
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Brief Summary
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This study is designed to evaluate the effects of a multimodal exercise program in the sprint performance and kinematics of adolescent rugby players. For this, an experimental study with an intervention group (IG) and a control group (CG) is designed. During 6 weeks of the 2022-2023 preseason of rugby seven, IG will include a multimodal exercise program in their training routine. Meanwhile, CG will maintain their training routine. The study will be developed in the Sport High Performance Centre of Balearic Islands during the season of rugby seven (from August to September, 2022). All rugby athletes from under-16 and under-18 autonomic rugby teams will be invited to participate in this study throughout an email invitation from their regional rugby federation. Prior to the beginning of the study, all participants will sign the inform consent, or their legal tutors in case of minors. The Ethical Committee of the local university approved this study (278CER22) according to the Declaration of Helsinki. One week before intervention period, sociodemographic and sportive data will be registered (age, sex, body mass, height, and sport experience). Body mass and height will be evaluated with a ±100-g precision digital weight scale (Tefal, France) and a t201-t4 adult height scale (Asimed, Spain), respectively. Also, the rugby players will complete a familiarization process consisting on a standardized warm up and 3 progressive sprints (i.e. 30 m at 50%, 70% and 90% of maximal effort). All testing procedure (pre-test and post-test) will be completed at a similar daytime (between 17h and 19h) on the same natural grass field. The test procedure listed in our study will consist on two maximal 30-m sprints to obtain mechanical variables of horizontal force-velocity profile and kinematics during sprinting. Players from IG will perform a multimodal exercise program two days per week during six weeks. This program will include running technical drills, exercises for lumbopelvic stabilization and resisted sprints. This program will be supervised by two experts in this field. The investigators hypothesize that those rugby players who add the multimodal exercise program to their training routine will increase mechanical and kinematics variables of sprint performance.

Official Title
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Effects of a Multimodal Exercise Program on the Kinematics and Sprint Performance of Young Rugby Players: an Experimental Study.

Conditions
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Exercise Training, Rugby, Adolescent

Intervention / Treatment
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* Other: Multimodal exercise program


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: to have at least 14 years old to have at least 2 years of experience as rugby player Exclusion Criteria: to have sustained a lower limb or lumbopelvic injury during the previous 6 months to start of the study to have sustained a lower limb or spine surgery during the previous 12 months to start of the study

Ages Eligible for Study
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Minimum Age: 14 Years
Maximum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Intervention group<br>Intervention group will add to their training routine a multimodal exercise program (two days per week, during six weeks). This program will include running technical drills, exercises for lumbopelvic stabilization and resisted sprints by using sled. | Other: Multimodal exercise program<br>* Running technical drills: pogo, askip, dribble, scissor, etc. Exercises for lumbopelvic stabilization: mobility exercises, hip thrust, dead lift, lunge to skip. Resisted sprints by using a sled: resistance leading to a 60% and 30% of optimal load (previously calculated)<br>|
| No Intervention: Control group<br>Control group will maintain their training routine. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Sprint performance | Sprint performance measured with MySprint. Resulting from maximal 30-m sprint, six pairs of brands with parallax corrected will be placed at 0, 5, 10, 15, 20 and 30 m to measure the five different split times in seconds during the 30-m trials. The camera, which records 240 frame per second, will be situated on a tripod (in the sagittal plane) 10 meters away from the fourth marker in meter 15. | Change from baseline and between group differences in sprint performance after the intervention period of 6 weeks | 
| Force-Velocity Profile (F-V) | F-V Profile measured by My Sprint App, resulting from maximal 30-m sprint, theorical maximal horizontal force (F0), maximal mechanical power output in the horizontal direction (Pmax), rate of decrease in RF with increasing speed during sprint acceleration (DRF), Slope of the linear F-V relationship (Sfv), Ratio of force (RF) and maximal value of RF (RFmax). The camera, which records 240 frame per second, will be situated on a tripod (in the sagittal plane) 10 meters away from the fourth marker in meter 15. | Change from baseline and between group differences in horizontal force-velocity profile after the intervention period of 6 weeks | 
| Sprint spatiotemporal and kinematics | Sprint spatiotemporal and kinematics will be analyzed with Kinovea program (v.0.8.15). The following variables will be analyzed: contact time (s), length step (m; horizontal displacement between the toe tips at adjacent touchdowns), step rate (Hz; the reciprocal of step duration). Moreover, in the frame that the foot touchdown and the frame that the foot touch off trunk and hip (ipsilateral and contralateral) angles will be quantified. The camera, which records 240 frame per second, will be situated 9 meters away from 22.5 m on a tripod at a height of 1.1 meters in the sagittal plane. | Change from baseline and between groups in sprint spatiotemporal and kinematics at 6 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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sprint performance, strength training, sprint kinematics