Exercise vs. stretching: which boosts flexibility more?
NCT ID NCT06469346
First seen Jun 27, 2026 · Last updated Jun 27, 2026
Summary
This study compares two methods to improve hamstring flexibility: eccentric exercise (like Nordic curls) and static stretching. Researchers will measure changes in knee extension and sit-and-reach distance in 42 healthy young men over 6 weeks. The goal is to see if eccentric exercise can increase flexibility as effectively as stretching, while also building strength.
What this could mean
Our plain-language read of the trial. This is informational only, not medical advice or a prediction.
- What this could lead to
- If it works, this could show that eccentric exercise is as good as or better than stretching for flexibility, with added strength benefits.
- What could go wrong
- This is a small, early-stage study in healthy young men only. Results may not apply to other groups or to injury prevention.
This is an AI summary of the original study and may miss details. Read our disclaimer.
Study facts
What this study's own registry entry says, in plain language.
- Phase
-
Not a phased trial
Phase numbers describe drug development. The registry uses this when they do not apply, as it does for trials of devices, procedures or behaviour changes, and for observational studies.
- Participants
-
About 42 people
The number the study aims to enrol. It can still change while the study runs.
- Started
-
Mar 2025
- Expected to finish
-
Sep 2026
An estimate. End dates often move.
- Lead sponsor
-
Other sponsor
The registry's catch-all category, for sponsors it does not file as a company, a government agency, or a research network.
Who can take part
This study's own entry requirements. Only the study team can say for certain whether you qualify.
- Ages
-
18 to 35 years
- Sex
-
Male participants only
- Healthy volunteers
-
Accepted
You do not need to have the condition being studied to take part.
Show the full entry requirements Hide the full entry requirements
Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.
Inclusion Criteria: * Masculine University students between 18 and 35 years old * Physically Inactive considering physical activity recommendations from World Health Organization * Bilateral hamstring muscle stiffness defined as \<160° in passive Knee Extension Angle Test * Body Max Index 18,5 \< BMI \< 24,9 kg/m2 Exclusion Criteria: * Lower back and lower limb (hip, thigh, knee, ankle) musculoskeletal injury in the last 12 months. * Hamstring injury (strain, tendinopathy, tendon avulsion) previously during the period of life * Dietary anabolic supplements consumption * Musculoskeletal, cardiovascular, respiratory o similar health condition that limits participation on physical activity programs * Regular resistance training (2 or more times per week, carrying out progressive training) in the previous 6 months * Smoker (1 cigarette per day)
Get updates
Get notified about this study
Sign up to get updates when this study changes or when new studies for Muscle stretching exercise are added.
Genom att skicka in godkänner du våra Användarvillkor
As listed by the trial registrant
The condition terms exactly as the trial's registrant entered them.
How to take part
Only the study team decides who joins. These are the ways to reach them.
-
The places running it
1 site. The list below names each one and where it is.
-
The official record
The full official record for this study. This one lists no contact details, but it is the first place any would appear.
-
A doctor treating you
A doctor who knows your case can contact a study site on your behalf, and can tell you whether this study is worth pursuing at all.
Contacts and locations
Locations
-
Universidad de La Frontera
Temuco, Cautín, 4780000, Chile
More trials for these conditions
Other studies related to the condition(s) this trial covers.