Sprint Mechanical OutputSEHTNCT07889089
Effects of Sprint and Eccentric Hamstring Training in Elite Youth Soccer Players
A study testing Eccentric hamstring strength training and Sprint training in people with Sprint Mechanical Output and Sprint Performance, run by Comenius University at 1 site in Slovakia.
Trial summary
This study will compare two different training methods used to improve sprint performance and hamstring strength in elite youth soccer players. Participants aged 16-17 years will be assigned to one of three groups: a sprint training group, an eccentric hamstring strength training group, or a control group. Read more about this study
- Who is it for?
- Ages 16 to 17 years, men onlyHealthy volunteers can take part
- Conditions the study is for
- Sprint Mechanical Output, Sprint Performance, Eccentric Hamstring Strength
- What is being tested?
- Eccentric hamstring strength training and Sprint training
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 15 participants
- Where
- 1 siteSlovakia
- Study dates
- 1 Nov 2026to 30 Jan 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 16 to 17 years
- Men only
- Healthy volunteers accepted
- Child
Who may be able to join
- Age 16-17 years and post-peak height velocity (post-PHV). Competing at the highest level of youth soccer in their country. Regular participation in soccer training (approximately 4 sessions per week, 90 minutes each) and competitive matches.
- Successful completion of the mandatory medical examination. At least 1 year of regular physical training, including sprint or resistance training within the club.
- Attendance of at least 80% of the intervention training sessions.
Who cannot join
- History of any lower-limb or trunk injury within 6 months before the pre-test. Sustaining a serious lower-limb or trunk injury during the experimental period. Regular participation in eccentric hamstring strength training or resisted sprint training during the 2 months before the pre-test measurements.
- Goalkeepers.will be automatically excluded from the study. Attendance below 80% of the intervention training sessions.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Slovakia1 site
Faculty of Physical education and sports, Comenius University
Bratislava, Bratislava Region, 814 69
Jozef Cholp MSc., Master of Science, +421 908767183, jozef.cholp@uniba.sk
Erika Zemková, Professor
About this study
Official title: Effects of Sprint and Eccentric Hamstring Training on Sprint Performance and Hamstring Strength in Elite Youth Soccer Players: Protocol for a Three-Arm Controlled Trial
This study will compare two different training methods used to improve sprint performance and hamstring strength in elite youth soccer players. Participants aged 16-17 years will be assigned to one of three groups: a sprint training group, an eccentric hamstring strength training group, or a control group. The two training programs will be performed for 6 weeks alongside the players' regular soccer and strength-conditioning training.
The main purpose of the study is to determine whether sprint training or eccentric hamstring strength training is more effective for improving sprint speed and sprint mechanical performance. Sprint performance will be assessed over 5, 10, 20, and 30 meters, together with mechanical variables derived from sprint force-velocity profiling. Eccentric hamstring strength will also be measured before and after the intervention.
The study will address whether a 6-week sprint training program can improve sprint performance and hamstring strength to a similar or greater extent than a targeted eccentric hamstring strength program. It is expected that sprint training will produce greater improvements in sprint-related performance, while eccentric hamstring training will produce greater improvements in eccentric hamstring strength.
Read the detailed description
This study is a three-arm, parallel-group controlled trial designed to compare the effects of sprint training and eccentric hamstring strength training in elite academy soccer players. The intervention period will last 6 weeks and will be conducted during the competitive season alongside the players' regular soccer and strength-conditioning programs. The study will include a sprint training group, an eccentric hamstring strength training group, and a matched external control group.
Following baseline testing, participants recruited from one elite soccer academy for the two experimental groups will be ranked according to their 30-m sprint time, matched according to baseline sprint performance, and then randomly allocated to either the sprint training group or the eccentric hamstring strength training group. This procedure is intended to minimize baseline differences in sprint performance between the two experimental groups. The control group will be recruited from a separate elite soccer academy and will be selected to achieve comparable baseline 30-m sprint performance to the experimental groups. The control group will not undergo random allocation. All groups will be assessed during the same competitive period and will continue their regular soccer and strength-conditioning activities throughout the study.
Before the intervention, the two experimental groups will complete a 1-week familiarization period consisting of two sessions. In the eccentric training group, familiarization will be used to establish appropriate individual loading and ensure a supramaximal eccentric stimulus. In the sprint training group, familiarization will include resisted sprint practice and individual load-velocity profiling to determine the external resistance corresponding to approximately a 50% velocity decrement.
The eccentric hamstring training program will consist primarily of two exercises: the Nordic hamstring curl and unilateral Roman chair hip extension. Both exercises will be performed with an emphasis on eccentric overload. The training volume will be intentionally kept relatively low because the intervention will be implemented during the competitive season. External resistance will be progressively increased when the prescribed repetitions can be completed without sufficient eccentric overload.
The sprint training group will perform two structured sprint sessions per week. The program will include resisted sprinting, acceleration-oriented exercises, horizontal and vertical plyometric exercises, and maximal-velocity fly sprints. Resisted sprints will be prescribed individually using approximately a 50% velocity decrement. Individual sled loads will be determined from load-velocity profiling performed during the familiarization period. The same sleds and artificial-turf surface will be used throughout the intervention to maintain consistent friction conditions.
The control group will continue its regular soccer and strength-conditioning program without the additional experimental eccentric hamstring or resisted sprint training interventions. The training schedule of the control group will be monitored to ensure that its general training exposure is comparable to that of the experimental groups as far as practically possible. All groups will participate in approximately four soccer training sessions per week, with each session lasting approximately 90 minutes.
Pre- and post-intervention testing will be performed under standardized conditions using the same testing procedures and equipment for all groups. Sprint testing will be conducted using electronic timing gates, sprint mechanical characteristics will be assessed using the 1080 Sprint system, and eccentric hamstring strength will be assessed using the NordBord system during the Nordic hamstring exercise. Participants will be instructed to avoid strenuous physical activity for at least 48 hours before testing.
Group differences over time will be analyzed using a two-way mixed-design analysis of variance, with group as the between-subject factor and time as the within-subject factor. The group × time interaction will be the primary statistical effect of interest. Bonferroni-adjusted post hoc comparisons will be used where appropriate, and effect sizes will be reported using partial eta squared and Cohen's d.
- Being tested
- Eccentric hamstring strength training, Sprint training
- Keywords
- eccentric training, sprint training, soccer, youth players
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Eccentric hamstring strength trainingOther
Participants will complete a 6-week eccentric hamstring strength training program in addition to regular soccer and strength-conditioning training. The intervention will include the Nordic hamstring curl and unilateral Roman chair hip extension, both performed with supramaximal eccentric overload. Training will be completed once in week 1 and twice per week during weeks 2-6. Nordic hamstring curl volume will be 2 × 4 repetitions, with external load added when participants can complete all repetitions through the full range of motion. For the unilateral Roman chair hip extension, participants will perform 2 × 6 repetitions per side with external resistance held on the chest. The lowering phase will be performed eccentrically with the trained limb, while return to the starting position will be assisted by the opposite limb. Loads will be increased when needed to maintain eccentric overload. Sessions will be performed before soccer training.
Sprint trainingOther
Participants will complete a 6-week structured sprint training program in addition to their regular soccer and strength-conditioning training. Two sprint-focused sessions will be performed per week, separated by at least 48 hours. The first session will include horizontal plyometric exercises, acceleration-oriented drills, and resisted 15-m sprints performed with an individualized sled load corresponding to approximately a 50% velocity decrement. The second session will include calf-strength and vertical plyometric exercises, resisted sprints at approximately 50% velocity decrement, and maximal-velocity fly sprints with a 20-m run-up. Resisted sprint volume will progress throughout the intervention. Individual sled loads will be determined using load-velocity profiling during familiarization. The same sleds and artificial-turf surface will be used throughout the intervention. All sessions will be performed before regular soccer training and supervised by a physical performance coach.
| Study group | Role | What they receive |
|---|---|---|
| Eccentric group | Experimental | Participants assigned to the eccentric hamstring strength training group will complete a 6-week eccentric strength training program in addition to their regular soccer and strength-conditioning training. The program will consist primarily of the Nordic hamstring curl and unilateral Roman chair hip extension, performed with an emphasis on supramaximal eccentric overload and progressive external loading when required. Receives: Other: Eccentric hamstring strength training |
| Sprint group | Experimental | Participants assigned to the sprint training group will complete a 6-week structured sprint training program in addition to their regular soccer and strength-conditioning training. The program will include resisted sprints prescribed at approximately 50% velocity decrement, acceleration-oriented exercises, horizontal and vertical plyometric exercises, calf-strength exercises, and maximal-velocity fly sprints. Sprint training will be performed twice per week. Receives: Other: Sprint training |
| Control Group | No intervention | Participants assigned to the control group will continue their regular soccer and strength-conditioning program throughout the 6-week study period without participating in the additional experimental eccentric hamstring or resisted sprint training programs. Regular soccer training will consist of approximately four 90-minute sessions per week. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Maximal Relative Theoretical Horizontal Force (F0)
Maximal relative theoretical horizontal force (F0) will be derived from the sprint force-velocity profile obtained during a 30-m sprint using the 1080 Sprint system. Participants will complete two trials, and the better value will be used for analysis.
Measured: From baseline to the post testing at 6 weeks
Maximal Theoretical Velocity (V0)
Maximal theoretical sprint velocity (V0) will be assessed during a 30-m sprint using the 1080 Sprint motorized resistance system (1080 Motion AB, Stockholm, Sweden). Participants will complete two trials with 3 minutes of rest between trials, and the better value will be used for analysis.
Measured: From baseline to the post testing at 6 weeks
Relative Maximal Power Output (Pmax)
Relative maximal mechanical power output (Pmax) will be derived from the sprint force-velocity profile during a 30-m sprint using the 1080 Sprint system. Participants will perform two trials separated by 3 minutes of rest, and the better value will be used for analysis.
Measured: From baseline to the post testing at 6 weeks
Maximal Ratio of Force (RFmax)
Maximal ratio of force (RFmax) will be derived from the sprint force-velocity profile obtained during a 30-m sprint using the 1080 Sprint system. Participants will perform two trials, and the better value will be used for analysis.
Measured: From baseline to the post testing at 6 weeks
5-m Sprint Time
Sprint time over 5 m will be measured using a single-beam electronic timing system (Witty Gate, Microgate, Bolzano, Italy) during a 30-m maximal sprint. Participants will perform two trials separated by 3 minutes of rest. The average time from the two trials will be used for analysis.
Measured: From baseline to the post testing at 6 weeks
10-m Sprint Time
Sprint time over 10 m will be measured using a single-beam electronic timing system during a 30-m maximal sprint. Participants will perform two trials separated by 3 minutes of rest. The average time from the two trials will be used for analysis.
Measured: From baseline to the post testing at 6 weeks
20-m Sprint Time
Sprint time over 20 m will be measured using a single-beam electronic timing system during a 30-m maximal sprint. Participants will perform two trials separated by 3 minutes of rest. The average time from the two trials will be used for analysis.
Measured: From baseline to the post testing at 6 weeks
30-m Sprint Time
Sprint time over 30 m will be measured using a single-beam electronic timing system. Participants will perform two maximal 30-m sprint trials separated by 3 minutes of rest. The average time from the two trials will be used for analysis.
Measured: From baseline to the post testing at 6 weeks
Secondary outcomes (1)
Eccentric Hamstring Strength
Eccentric hamstring strength will be assessed using the NordBord device (VALD Performance, Newstead, Australia) during the Nordic hamstring exercise. Following three submaximal familiarization efforts, participants will perform three maximal efforts. The best value obtained for each limb will be used to derive the bilateral eccentric hamstring strength score for analysis.
Measured: From baseline to the post testing at 6 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted22 Oct 2026
- Study start1 Nov 2026 (estimated)
- Primary completion20 Jan 2027 (estimated)
- Study completion30 Jan 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (49)Papers the sponsor has linked to this study.
- Other trials for Sprint Mechanical OutputStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Model description
- Participants from one elite soccer academy will be matched according to baseline 30-m sprint performance and randomly allocated to either the sprint training group or the eccentric hamstring strength training group. A matched external control group will be recruited from a separate elite soccer academy and selected to provide comparable baseline sprint performance. The control group will not undergo random allocation. All three groups will be followed concurrently over a 6-week study period and will complete standardized pre- and post-intervention assessments.
- Masking
- None (open label)
- Enrolment
- 15 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Comenius University
- Sponsor type
- University, hospital or other
- Collaborators
- FC DAC 1904 Dunajská Streda
- Responsible party
- Principal investigator, Jozef Cholp, Comenius University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07889089
- Sponsor's protocol ID
- UK-FTVS-SEHT-2026-01
- Other IDs
- (No. 1/0699/26)
- Acronym
- SEHT
- Status last verified
- Oct 2026
- First submitted
- 8 Oct 2026
- Last updated
- 22 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Stockdale RA, Dos'Santos T, McDaid K, Nagy P, Gaffney CJ, Barry TJ. Sprinting Force-Velocity and Acceleration-Speed Profiling in Elite Soccer to Augment Performance and Mitigate Hamstring Injury Risk: A Narrative Review With Practical Applications. Strength & Conditioning Journal. 2026;48:125-41.
Malý, T., F. Zahálka, P. Hráský, L. Malá, J. Ižovská, D. Bujnovský, M. Dragijský, and J. Mihal. Age-Related Differences in Linear Sprint and Power Characteristics in Youth Elite Soccer Players. JPES. 2015:857-63.
van Dyk N, Behan FP, Whiteley R. Including the Nordic hamstring exercise in injury prevention programmes halves the rate of hamstring injuries: a systematic review and meta-analysis of 8459 athletes. Br J Sports Med. 2019 Nov;53(21):1362-1370. doi: 10.1136/bjsports-2018-100045. Epub 2019 Feb 26.
PubMed 30808663van der Horst N, Smits DW, Petersen J, Goedhart EA, Backx FJ. The preventive effect of the nordic hamstring exercise on hamstring injuries in amateur soccer players: a randomized controlled trial. Am J Sports Med. 2015 Jun;43(6):1316-23. doi: 10.1177/0363546515574057. Epub 2015 Mar 20.
PubMed 25794868Timmins RG, Bourne MN, Shield AJ, Williams MD, Lorenzen C, Opar DA. Short biceps femoris fascicles and eccentric knee flexor weakness increase the risk of hamstring injury in elite football (soccer): a prospective cohort study. Br J Sports Med. 2016 Dec;50(24):1524-1535. doi: 10.1136/bjsports-2015-095362. Epub 2015 Dec 16.
PubMed 26675089Stavridis I, Ekizos A, Zisi M, Agilara GO, Tsolakis C, Terzis G, Paradisis G. The Effects of Heavy Resisted Sled Pulling on Sprint Mechanics and Spatiotemporal Parameters. J Strength Cond Res. 2023 Dec 1;37(12):2346-2353. doi: 10.1519/JSC.0000000000004548.
PubMed 38015728Robles-Palazon FJ, Ruiz-Perez I, Aparicio-Sarmiento A, Cejudo A, Ayala F, Sainz de Baranda P. Incidence, burden, and pattern of injuries in Spanish male youth soccer players: A prospective cohort study. Phys Ther Sport. 2022 Jul;56:48-59. doi: 10.1016/j.ptsp.2022.06.005. Epub 2022 Jun 30.
PubMed 35816871Ripley NJ, Cuthbert M, Ross S, Comfort P, McMahon JJ. The Effect of Exercise Compliance on Risk Reduction for Hamstring Strain Injury: A Systematic Review and Meta-Analyses. Int J Environ Res Public Health. 2021 Oct 27;18(21):11260. doi: 10.3390/ijerph182111260.
PubMed 34769778Rakovic E, Paulsen G, Helland C, Haugen T, Eriksrud O. Validity and Reliability of a Motorized Sprint Resistance Device. J Strength Cond Res. 2022 Aug 1;36(8):2335-2338. doi: 10.1519/JSC.0000000000003830. Epub 2022 Jan 5.
PubMed 35916750Prince C, Morin JB, Mendiguchia J, Lahti J, Guex K, Edouard P, Samozino P. Sprint Specificity of Isolated Hamstring-Strengthening Exercises in Terms of Muscle Activity and Force Production. Front Sports Act Living. 2021 Jan 21;2:609636. doi: 10.3389/fspor.2020.609636. eCollection 2020.
PubMed 33554110Pareja-Blanco F, Asian-Clemente JA, Saez de Villarreal E. Combined Squat and Light-Load Resisted Sprint Training for Improving Athletic Performance. J Strength Cond Res. 2021 Sep 1;35(9):2457-2463. doi: 10.1519/JSC.0000000000003171.
PubMed 31022105Opar DA, Williams MD, Shield AJ. Hamstring strain injuries: factors that lead to injury and re-injury. Sports Med. 2012 Mar 1;42(3):209-26. doi: 10.2165/11594800-000000000-00000.
PubMed 22239734Morin JB, Capelo-Ramirez F, Rodriguez-Perez MA, Cross MR, Jimenez-Reyes P. Individual Adaptation Kinetics Following Heavy Resisted Sprint Training. J Strength Cond Res. 2022 Apr 1;36(4):1158-1161. doi: 10.1519/JSC.0000000000003546.
PubMed 32058358Morin JB, Gimenez P, Edouard P, Arnal P, Jimenez-Reyes P, Samozino P, Brughelli M, Mendiguchia J. Sprint Acceleration Mechanics: The Major Role of Hamstrings in Horizontal Force Production. Front Physiol. 2015 Dec 24;6:404. doi: 10.3389/fphys.2015.00404. eCollection 2015.
PubMed 26733889Moran J, Vali N, Drury B, Hammami R, Tallent J, Chaabene H, Ramirez-Campillo R. The effect of volume equated 1- versus 2-day formats of Nordic hamstring exercise training on fitness in youth soccer players: A randomised controlled trial. PLoS One. 2022 Dec 29;17(12):e0277437. doi: 10.1371/journal.pone.0277437. eCollection 2022.
PubMed 36580466
Study at a glance
From the registry record, last updated by the sponsor on 22 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effects of Sprint and Eccentric Hamstring Training on Sprint Performance and Hamstring Strength in Elite Youth Soccer Players: Protocol for a Three-Arm Controlled Trial
- ClinicalTrials.gov ID
- NCT07889089
- Acronym / sponsor ID
- SEHT / UK-FTVS-SEHT-2026-01
- Keywords
- eccentric training, sprint training, soccer, youth players
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 15 participants (estimated)
- Lead sponsor
- Comenius UniversityUniversity, hospital or other
- Collaborators
- FC DAC 1904 Dunajská Streda
- Study start
- 1 Nov 2026 (estimated)
- Primary completion
- 20 Jan 2027 (estimated)
- Study completion
- 30 Jan 2027 (estimated)
- First posted
- 22 Oct 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study will compare two different training methods used to improve sprint performance and hamstring strength in elite youth soccer players. Participants aged 16-17 years will be assigned to one of three groups: a sprint training group, an eccentric hamstring strength training group, or a control group. The two training programs will be performed for 6 weeks alongside the players' regular soccer and strength-conditioning training.
The main purpose of the study is to determine whether sprint training or eccentric hamstring strength training is more effective for improving sprint speed and sprint mechanical performance. Sprint performance will be assessed over 5, 10, 20, and 30 meters, together with mechanical variables derived from sprint force-velocity profiling. Eccentric hamstring strength will also be measured before and after the intervention.
The study will address whether a 6-week sprint training program can improve sprint performance and hamstring strength to a similar or greater extent than a targeted eccentric hamstring strength program. It is expected that sprint training will produce greater improvements in sprint-related performance, while eccentric hamstring training will produce greater improvements in eccentric hamstring strength.
Detailed description
This study is a three-arm, parallel-group controlled trial designed to compare the effects of sprint training and eccentric hamstring strength training in elite academy soccer players. The intervention period will last 6 weeks and will be conducted during the competitive season alongside the players' regular soccer and strength-conditioning programs. The study will include a sprint training group, an eccentric hamstring strength training group, and a matched external control group.
Following baseline testing, participants recruited from one elite soccer academy for the two experimental groups will be ranked according to their 30-m sprint time, matched according to baseline sprint performance, and then randomly allocated to either the sprint training group or the eccentric hamstring strength training group. This procedure is intended to minimize baseline differences in sprint performance between the two experimental groups. The control group will be recruited from a separate elite soccer academy and will be selected to achieve comparable baseline 30-m sprint performance to the experimental groups. The control group will not undergo random allocation. All groups will be assessed during the same competitive period and will continue their regular soccer and strength-conditioning activities throughout the study.
Before the intervention, the two experimental groups will complete a 1-week familiarization period consisting of two sessions. In the eccentric training group, familiarization will be used to establish appropriate individual loading and ensure a supramaximal eccentric stimulus. In the sprint training group, familiarization will include resisted sprint practice and individual load-velocity profiling to determine the external resistance corresponding to approximately a 50% velocity decrement.
The eccentric hamstring training program will consist primarily of two exercises: the Nordic hamstring curl and unilateral Roman chair hip extension. Both exercises will be performed with an emphasis on eccentric overload. The training volume will be intentionally kept relatively low because the intervention will be implemented during the competitive season. External resistance will be progressively increased when the prescribed repetitions can be completed without sufficient eccentric overload.
The sprint training group will perform two structured sprint sessions per week. The program will include resisted sprinting, acceleration-oriented exercises, horizontal and vertical plyometric exercises, and maximal-velocity fly sprints. Resisted sprints will be prescribed individually using approximately a 50% velocity decrement. Individual sled loads will be determined from load-velocity profiling performed during the familiarization period. The same sleds and artificial-turf surface will be used throughout the intervention to maintain consistent friction conditions.
The control group will continue its regular soccer and strength-conditioning program without the additional experimental eccentric hamstring or resisted sprint training interventions. The training schedule of the control group will be monitored to ensure that its general training exposure is comparable to that of the experimental groups as far as practically possible. All groups will participate in approximately four soccer training sessions per week, with each session lasting approximately 90 minutes.
Pre- and post-intervention testing will be performed under standardized conditions using the same testing procedures and equipment for all groups. Sprint testing will be conducted using electronic timing gates, sprint mechanical characteristics will be assessed using the 1080 Sprint system, and eccentric hamstring strength will be assessed using the NordBord system during the Nordic hamstring exercise. Participants will be instructed to avoid strenuous physical activity for at least 48 hours before testing.
Group differences over time will be analyzed using a two-way mixed-design analysis of variance, with group as the between-subject factor and time as the within-subject factor. The group × time interaction will be the primary statistical effect of interest. Bonferroni-adjusted post hoc comparisons will be used where appropriate, and effect sizes will be reported using partial eta squared and Cohen's d.
Study design
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 3
- Model description
- Participants from one elite soccer academy will be matched according to baseline 30-m sprint performance and randomly allocated to either the sprint training group or the eccentric hamstring strength training group. A matched external control group will be recruited from a separate elite soccer academy and selected to provide comparable baseline sprint performance. The control group will not undergo random allocation. All three groups will be followed concurrently over a 6-week study period and will complete standardized pre- and post-intervention assessments.
| Arm | Type | Receives |
|---|---|---|
| Eccentric group | Experimental | Other: Eccentric hamstring strength trainingParticipants assigned to the eccentric hamstring strength training group will complete a 6-week eccentric strength training program in addition to their regular soccer and strength-conditioning training. The program will consist primarily of the Nordic hamstring curl and unilateral Roman chair hip extension, performed with an emphasis on supramaximal eccentric overload and progressive external loading when required. |
| Sprint group | Experimental | Other: Sprint trainingParticipants assigned to the sprint training group will complete a 6-week structured sprint training program in addition to their regular soccer and strength-conditioning training. The program will include resisted sprints prescribed at approximately 50% velocity decrement, acceleration-oriented exercises, horizontal and vertical plyometric exercises, calf-strength exercises, and maximal-velocity fly sprints. Sprint training will be performed twice per week. |
| Control Group | No intervention | –Participants assigned to the control group will continue their regular soccer and strength-conditioning program throughout the 6-week study period without participating in the additional experimental eccentric hamstring or resisted sprint training programs. Regular soccer training will consist of approximately four 90-minute sessions per week. |
Who may qualify
- Ages
- 16 to 17 years
- Sex
- Male only
- Healthy volunteers
- Accepted
- Age groups
- Child
Key inclusion criteria (3 listed)
- Age 16-17 years and post-peak height velocity (post-PHV). Competing at the highest level of youth soccer in their country. Regular participation in soccer training (approximately 4 sessions per week, 90 minutes each) and competitive matches.
- Successful completion of the mandatory medical examination. At least 1 year of regular physical training, including sprint or resistance training within the club.
- Attendance of at least 80% of the intervention training sessions.
Key exclusion criteria (2 listed)
- History of any lower-limb or trunk injury within 6 months before the pre-test. Sustaining a serious lower-limb or trunk injury during the experimental period. Regular participation in eccentric hamstring strength training or resisted sprint training during the 2 months before the pre-test measurements.
- Goalkeepers.will be automatically excluded from the study. Attendance below 80% of the intervention training sessions.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Eccentric hamstring strength trainingParticipants will complete a 6-week eccentric hamstring strength training program in addition to regular soccer and strength-conditioning training. The intervention will include the Nordic hamstring curl and unilateral Roman chair hip extension, both performed with supramaximal eccentric overload. Training will be completed once in week 1 and twice per week during weeks 2-6. Nordic hamstring curl volume will be 2 × 4 repetitions, with external load added when participants can complete all repetitions through the full range of motion. For the unilateral Roman chair hip extension, participants will perform 2 × 6 repetitions per side with external resistance held on the chest. The lowering phase will be performed eccentrically with the trained limb, while return to the starting position will be assisted by the opposite limb. Loads will be increased when needed to maintain eccentric overload. Sessions will be performed before soccer training. | Other | Eccentric group |
| Sprint trainingParticipants will complete a 6-week structured sprint training program in addition to their regular soccer and strength-conditioning training. Two sprint-focused sessions will be performed per week, separated by at least 48 hours. The first session will include horizontal plyometric exercises, acceleration-oriented drills, and resisted 15-m sprints performed with an individualized sled load corresponding to approximately a 50% velocity decrement. The second session will include calf-strength and vertical plyometric exercises, resisted sprints at approximately 50% velocity decrement, and maximal-velocity fly sprints with a 20-m run-up. Resisted sprint volume will progress throughout the intervention. Individual sled loads will be determined using load-velocity profiling during familiarization. The same sleds and artificial-turf surface will be used throughout the intervention. All sessions will be performed before regular soccer training and supervised by a physical performance coach. | Other | Sprint group |
Primary outcome
Maximal Relative Theoretical Horizontal Force (F0)
Time frame: From baseline to the post testing at 6 weeks
Maximal relative theoretical horizontal force (F0) will be derived from the sprint force-velocity profile obtained during a 30-m sprint using the 1080 Sprint system. Participants will complete two trials, and the better value will be used for analysis.
Maximal Theoretical Velocity (V0)
Time frame: From baseline to the post testing at 6 weeks
Maximal theoretical sprint velocity (V0) will be assessed during a 30-m sprint using the 1080 Sprint motorized resistance system (1080 Motion AB, Stockholm, Sweden). Participants will complete two trials with 3 minutes of rest between trials, and the better value will be used for analysis.
Relative Maximal Power Output (Pmax)
Time frame: From baseline to the post testing at 6 weeks
Relative maximal mechanical power output (Pmax) will be derived from the sprint force-velocity profile during a 30-m sprint using the 1080 Sprint system. Participants will perform two trials separated by 3 minutes of rest, and the better value will be used for analysis.
Maximal Ratio of Force (RFmax)
Time frame: From baseline to the post testing at 6 weeks
Maximal ratio of force (RFmax) will be derived from the sprint force-velocity profile obtained during a 30-m sprint using the 1080 Sprint system. Participants will perform two trials, and the better value will be used for analysis.
5-m Sprint Time
Time frame: From baseline to the post testing at 6 weeks
Sprint time over 5 m will be measured using a single-beam electronic timing system (Witty Gate, Microgate, Bolzano, Italy) during a 30-m maximal sprint. Participants will perform two trials separated by 3 minutes of rest. The average time from the two trials will be used for analysis.
10-m Sprint Time
Time frame: From baseline to the post testing at 6 weeks
Sprint time over 10 m will be measured using a single-beam electronic timing system during a 30-m maximal sprint. Participants will perform two trials separated by 3 minutes of rest. The average time from the two trials will be used for analysis.
20-m Sprint Time
Time frame: From baseline to the post testing at 6 weeks
Sprint time over 20 m will be measured using a single-beam electronic timing system during a 30-m maximal sprint. Participants will perform two trials separated by 3 minutes of rest. The average time from the two trials will be used for analysis.
30-m Sprint Time
Time frame: From baseline to the post testing at 6 weeks
Sprint time over 30 m will be measured using a single-beam electronic timing system. Participants will perform two maximal 30-m sprint trials separated by 3 minutes of rest. The average time from the two trials will be used for analysis.
1 secondary outcome
Eccentric Hamstring Strength
Time frame: From baseline to the post testing at 6 weeks
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 22 Oct 2026.
- BackgroundStockdale RA, Dos'Santos T, McDaid K, Nagy P, Gaffney CJ, Barry TJ. Sprinting Force-Velocity and Acceleration-Speed Profiling in Elite Soccer to Augment Performance and Mitigate Hamstring Injury Risk: A Narrative Review With Practical Applications. Strength & Conditioning Journal. 2026;48:125-41.
- BackgroundMalý, T., F. Zahálka, P. Hráský, L. Malá, J. Ižovská, D. Bujnovský, M. Dragijský, and J. Mihal. Age-Related Differences in Linear Sprint and Power Characteristics in Youth Elite Soccer Players. JPES. 2015:857-63.
- Background: PubMed 30808663van Dyk N, Behan FP, Whiteley R. Including the Nordic hamstring exercise in injury prevention programmes halves the rate of hamstring injuries: a systematic review and meta-analysis of 8459 athletes. Br J Sports Med. 2019 Nov;53(21):1362-1370. doi: 10.1136/bjsports-2018-100045. Epub 2019 Feb 26.
- Background: PubMed 25794868van der Horst N, Smits DW, Petersen J, Goedhart EA, Backx FJ. The preventive effect of the nordic hamstring exercise on hamstring injuries in amateur soccer players: a randomized controlled trial. Am J Sports Med. 2015 Jun;43(6):1316-23. doi: 10.1177/0363546515574057. Epub 2015 Mar 20.
- Background: PubMed 26675089Timmins RG, Bourne MN, Shield AJ, Williams MD, Lorenzen C, Opar DA. Short biceps femoris fascicles and eccentric knee flexor weakness increase the risk of hamstring injury in elite football (soccer): a prospective cohort study. Br J Sports Med. 2016 Dec;50(24):1524-1535. doi: 10.1136/bjsports-2015-095362. Epub 2015 Dec 16.
- Background: PubMed 38015728Stavridis I, Ekizos A, Zisi M, Agilara GO, Tsolakis C, Terzis G, Paradisis G. The Effects of Heavy Resisted Sled Pulling on Sprint Mechanics and Spatiotemporal Parameters. J Strength Cond Res. 2023 Dec 1;37(12):2346-2353. doi: 10.1519/JSC.0000000000004548.
- Background: PubMed 35816871Robles-Palazon FJ, Ruiz-Perez I, Aparicio-Sarmiento A, Cejudo A, Ayala F, Sainz de Baranda P. Incidence, burden, and pattern of injuries in Spanish male youth soccer players: A prospective cohort study. Phys Ther Sport. 2022 Jul;56:48-59. doi: 10.1016/j.ptsp.2022.06.005. Epub 2022 Jun 30.
- Background: PubMed 34769778Ripley NJ, Cuthbert M, Ross S, Comfort P, McMahon JJ. The Effect of Exercise Compliance on Risk Reduction for Hamstring Strain Injury: A Systematic Review and Meta-Analyses. Int J Environ Res Public Health. 2021 Oct 27;18(21):11260. doi: 10.3390/ijerph182111260.
- Background: PubMed 35916750Rakovic E, Paulsen G, Helland C, Haugen T, Eriksrud O. Validity and Reliability of a Motorized Sprint Resistance Device. J Strength Cond Res. 2022 Aug 1;36(8):2335-2338. doi: 10.1519/JSC.0000000000003830. Epub 2022 Jan 5.
- Background: PubMed 33554110Prince C, Morin JB, Mendiguchia J, Lahti J, Guex K, Edouard P, Samozino P. Sprint Specificity of Isolated Hamstring-Strengthening Exercises in Terms of Muscle Activity and Force Production. Front Sports Act Living. 2021 Jan 21;2:609636. doi: 10.3389/fspor.2020.609636. eCollection 2020.
- Background: PubMed 31022105Pareja-Blanco F, Asian-Clemente JA, Saez de Villarreal E. Combined Squat and Light-Load Resisted Sprint Training for Improving Athletic Performance. J Strength Cond Res. 2021 Sep 1;35(9):2457-2463. doi: 10.1519/JSC.0000000000003171.
- Background: PubMed 22239734Opar DA, Williams MD, Shield AJ. Hamstring strain injuries: factors that lead to injury and re-injury. Sports Med. 2012 Mar 1;42(3):209-26. doi: 10.2165/11594800-000000000-00000.
- Individual participant dataSharing planned: No
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Faculty of Physical education and sports, Comenius University
Bratislava, Slovakia
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Eccentric hamstring strength training and Sprint training in people with Sprint Mechanical Output and Sprint Performance, run by Comenius University at 1 site in Slovakia.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 2 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 22 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Slovakia. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Each site lists its own contact: choose the nearest one under Trial locations. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Maximal Relative Theoretical Horizontal Force (F0) (time frame: From baseline to the post testing at 6 weeks). The study lists 8 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07889089, which also lists 49 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 22 Oct 2026.