Exercise Induced HypoalgesiaFATIGUEIHNCT07577622
The Role of Fatigue Associated With Strength Training in Exercise-induced Hypoalgesia
A study testing Seated leg extension machine: low fatigue and Seated leg extension machine: high fatigue in people with Exercise Induced Hypoalgesia and Healthy Adult Volunteer, run by Universidad Miguel Hernandez de Elche at 1 site in Spain.
Trial summary
Strength exercise is an active and dynamic activity that involves applying force against a resistance. This produces fatigue, seen as a reduced ability to apply force during and after the exercise, and perceived effort, which is a person's subjective feeling of how hard they are working. Read more about this study
- Who is it for?
- Ages 18 to 45 yearsHealthy volunteers can take part
- Conditions the study is for
- Exercise Induced Hypoalgesia, Healthy Adult Volunteer
- What is being tested?
- Seated leg extension machine: low fatigue and Seated leg extension machine: high fatigue
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 27 participants
- Where
- 1 siteSpain
- Study dates
- 15 May 2026to 30 Jun 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 18 to 45 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Healthy, asymptomatic subjects
- Being physically active
Who cannot join
- Experiencing episodes of acute pain in any part of the body.
- Having chronic pain or a recent history of chronic pain conditions considered resolved within the last 6 months.
- Having a serious illness or inability to perform moderate or intense physical activity.
- Having taken pain relievers, fever reducers, anti-inflammatory drugs (NSAIDs), steroids, opioids, or similar medications in the 24 hours before a session.
- Having consumed alcohol or other psychoactive substances, caffeine, or other stimulants in the 24 hours before a session.
- Having performed tiring physical activity or strength exercise in the 24 hours before a session.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Spain1 site
Universidad Miguel Hernández
Alicante, ALICANTE, 03550
Miguel Delicado Miralles, Physiotherapy, +34 679788377, mdelicado@umh.es
About this study
Official title: The Role of Fatigue Associated With Different Protocols of Strength Training in Exercise-induced Hypoalgesia: A Randomized Crossover Trial
Strength exercise is an active and dynamic activity that involves applying force against a resistance. This produces fatigue, seen as a reduced ability to apply force during and after the exercise, and perceived effort, which is a person's subjective feeling of how hard they are working.
Strength exercise can also be used for therapy, as it has many benefits for different parts of the body. One of these is changing how the individual feels pain. It has been shown that doing strength exercises can reduce pain perception, a phenomenon called exercise-induced hypoalgesia (EIH), although the exact physical reasons and the amount of exercise needed to cause this effect are not yet known.
Read more
One of the most studied exercises in this area is the leg extension machine. This is a specific exercise where the legs move freely (open kinetic chain) and the machine guides the movement, which helps keep things stable and limits the effect of other factors. It is usually used to strengthen and grow the muscles in the front of the thigh, especially the quadriceps, but it can also be used to study the effects on EIH.
The main goal of this study is to see if fatigue and perceived effort during strength exercise are important for EIH to happen in healthy people. Participants will complete 3 sessions, at least 7 days apart. These will include a control session and 2 sessions designed to show different levels of fatigue. Before, during, and after the sessions, the investigators will measure pain sensitivity, isometric strength, and perceived effort. Also, there will be a test to find the maximum weight for 10 repetitions and several questionnaires to collect basic info (sex, age, height...), weekly physical activity, experience with strength training, and other factors like sleep quality, stress, and mood. All this information will be completely anonymous when the study results are shared.
- Being tested
- Seated leg extension machine: low fatigue, Seated leg extension machine: high fatigue, Seated leg extension: control
- Keywords
- Fatigue, Exercise, Hypoalgesia, Strength training, Healthy adult, leg extension
- Medical subject headings
- Fatigue, Motor Activity
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Seated leg extension machine: low fatigueBehavioural
Seated leg extension machine using 10RM external load for 6 sets of 5 repetitions with180 seconds rest between sets and a cadence of 1:2 second concentric:eccentric
Seated leg extension machine: high fatigueBehavioural
Seated leg extension machine using 10RM external load for 3 sets of 10 repetitions with 180 seconds rest between sets and a cadence of 1:2 second concentric:eccentric
Seated leg extension: controlBehavioural
Seated leg extension machine using no external load for 6 sets of 5 repetitions with 180 seconds rest between sets and a cadence of 1:2 second concentric:eccentric
| Study group | Role | What they receive |
|---|---|---|
| Control | Sham comparator | Not described Receives: Behavioral: Seated leg extension: control |
| Low fatigue | Experimental | Not described Receives: Behavioral: Seated leg extension machine: low fatigue |
| High fatigue | Experimental | Not described Receives: Behavioral: Seated leg extension machine: high fatigue |
What is being measured
The primary outcome is the main question the study is designed to answer.
Pain pressure threshold
Pain pressure threshold measured with an analogic algometer (Baseline Dolorimeter, MVS In Motion SL, Belgium), in kilograms. These measurements will be taken at a local level (on one of the thighs, over the rectus femoris of the quadriceps, at the midpoint between the pelvic surface and the patella) and at a distance (on the neck over the belly of one of the upper trapezius muscles, at the midpoint between the surface of C7 and the acromion). The pressure will be applied at a rate of 1kg/s and the patient will be instructed to notify the first instance of pain.
Measured: Baseline, immediately post-exercise, 30 minutes after exercise
Pressure-evoked pain
Pain evoked by a 6kg pressure exerted with an analogic algometer (Baseline Dolorimeter, MVS In Motion SL, Belgium), at a rate of 1kg/s, measured with a numeric rating scale where zero is equivalent to no pain and 10 indicates the worst possible pain.
These measurements will be taken at a local level (on one of the thighs, over the rectus femoris of the quadriceps, at the midpoint between the pelvic surface and the patella) and at a distance (on the neck over the belly of one of the upper trapezius muscles, at the midpoint between the surface of C7 and the acromion).
Measured: Baseline, immediately post-exercise, 30 minutes after exercise
RPE (Rating of Perceived Exertion)
Perceived exertion was measured on OMNI-Resistance exercise Scale where 0 is equivalent to no effort and 10 indicates maximal exertion.
Measured: Immediately after each set of the training session
sRPE (Session rating of perceived exertion)
Session Perceived Exertion was measured on a scale where 0 is equivalent to no effort and 10 indicates maximal exertion.
Measured: Monitoring will take place 30 minutes after the final set, ensuring that the exertion from the last set does not interfere with the overall session RPE.
Repetitions in Reserve (RIR)
Using the ERF (Estimated Repetitions to Failure) scale where 0 is equivalent to maximal effort or muscular failure, and higher numbers indicate lower effort. For this purpose, subjects will be asked how many more repetitions they believe they could have performed after each set.
Measured: Immediately after each set of the training session.
Muscle fatigue
This will be monitored taking into account objective variables (not dependent on the patient's subjective report), through isometric knee extension action tests measured by dynamometry using a portable load cell (Model 620 Tedea-Huntleigh, Vishay Precision Group Inc., Holon, Israel) and Chronojump software (Chronojump Bosco System, Barcelona, Spain). The variables used are the maximal voluntary isometric contraction (MVIC) measured in Newtons (N) and the Rate of Force Development (RFD) which calculates the slope of the force-time curve.
Measured: Baseline, immediately post-exercise, 30 minutes after exercise
Secondary outcomes (3)
Kinematic measures
Angular position (º), velocity(º/s) and acceleration(º/s^2) of the machine's pad during the exercise will be recorded using an accelerometer (BWT901CL, WitMotion Shenzhen Co., Ltd).
Measured: During each set of the exercise intervention in all 3 sessions (3 or 6 sets depending on each arm). Total measurement time approximately 3 minutes during a single experimental session (as the device will stop recording during rest periods between sets).
Wellness
Data regarding fatigue, sleep quality, DOMS, stress levels and mood will be tracked every session using a Wellness questionnaire where 5 is the best outcome and 1 is the worst for each individual item.
Measured: Prior to each exercise session.
Fitness level
The subject's level of physical activity will be collected via the IPAQ (International Physical Activity Questionnaire), which accounts for every physical activity performed throughout the week prior to taking the questionnare and converts them to METs (Metabolic Equivalent of a Task). Higher values indicate higher degree of fitness, and 0 being the floor (zero physical activity).
Measured: Baseline (Day 1)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted11 May 2026
- Study start15 May 2026 (estimated)
- Primary completion30 Jun 2027 (estimated)
- Study completion30 Jun 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (3)Papers the sponsor has linked to this study.
- Other trials for Exercise Induced HypoalgesiaStudies 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
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- Double-blind randomized crossover controlled trial
- Masking
- Double blind
- Who is masked
- Participant, Outcomes assessor
- Enrolment
- 27 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Universidad Miguel Hernandez de Elche
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Jaime Gascón Jaen, Universidad Miguel Hernandez de Elche
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07577622
- Sponsor's protocol ID
- DPC.MDM.240801
- Acronym
- FATIGUEIH
- Status last verified
- May 2026
- First submitted
- 22 Apr 2026
- Last updated
- 11 May 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Hogge R, Mascheri M, Shurik D, Hanney WJ, Anderson AW. High-Fatigue Dynamic Resistance Exercise Induces Significant Hypoalgesia Effect. J Strength Cond Res. 2025 Feb 1;39(2):165-172. doi: 10.1519/JSC.0000000000004985. Epub 2024 Nov 26.
PubMed 39590221Vaegter HB, Jones MD. Exercise-induced hypoalgesia after acute and regular exercise: experimental and clinical manifestations and possible mechanisms in individuals with and without pain. Pain Rep. 2020 Sep 23;5(5):e823. doi: 10.1097/PR9.0000000000000823. eCollection 2020 Sep-Oct.
PubMed 33062901Wewege MA, Jones MD. Exercise-Induced Hypoalgesia in Healthy Individuals and People With Chronic Musculoskeletal Pain: A Systematic Review and Meta-Analysis. J Pain. 2021 Jan;22(1):21-31. doi: 10.1016/j.jpain.2020.04.003. Epub 2020 Jun 26.
PubMed 32599154
Study at a glance
From the registry record, last updated by the sponsor on 11 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Role of Fatigue Associated With Different Protocols of Strength Training in Exercise-induced Hypoalgesia: A Randomized Crossover Trial
- ClinicalTrials.gov ID
- NCT07577622
- Acronym / sponsor ID
- FATIGUEIH / DPC.MDM.240801
- Keywords
- Fatigue, Exercise, Hypoalgesia, Strength training, Healthy adult, leg extension
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 27 participants (estimated)
- Lead sponsor
- Universidad Miguel Hernandez de ElcheUniversity, hospital or other
- Study start
- 15 May 2026 (estimated)
- Primary completion
- 30 Jun 2027 (estimated)
- Study completion
- 30 Jun 2027 (estimated)
- First posted
- 11 May 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.
Strength exercise is an active and dynamic activity that involves applying force against a resistance. This produces fatigue, seen as a reduced ability to apply force during and after the exercise, and perceived effort, which is a person's subjective feeling of how hard they are working.
Strength exercise can also be used for therapy, as it has many benefits for different parts of the body. One of these is changing how the individual feels pain. It has been shown that doing strength exercises can reduce pain perception, a phenomenon called exercise-induced hypoalgesia (EIH), although the exact physical reasons and the amount of exercise needed to cause this effect are not yet known.
One of the most studied exercises in this area is the leg extension machine. This is a specific exercise where the legs move freely (open kinetic chain) and the machine guides the movement, which helps keep things stable and limits the effect of other factors. It is usually used to strengthen and grow the muscles in the front of the thigh, especially the quadriceps, but it can also be used to study the effects on EIH.
The main goal of this study is to see if fatigue and perceived effort during strength exercise are important for EIH to happen in healthy people. Participants will complete 3 sessions, at least 7 days apart. These will include a control session and 2 sessions designed to show different levels of fatigue. Before, during, and after the sessions, the investigators will measure pain sensitivity, isometric strength, and perceived effort. Also, there will be a test to find the maximum weight for 10 repetitions and several questionnaires to collect basic info (sex, age, height...), weekly physical activity, experience with strength training, and other factors like sleep quality, stress, and mood. All this information will be completely anonymous when the study results are shared.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind (participant, outcomes assessor)
- Number of arms
- 3
- Model description
- Double-blind randomized crossover controlled trial
| Arm | Type | Receives |
|---|---|---|
| Control | Sham comparator | Behavioral: Seated leg extension: control |
| Low fatigue | Experimental | Behavioral: Seated leg extension machine: low fatigue |
| High fatigue | Experimental | Behavioral: Seated leg extension machine: high fatigue |
Who may qualify
- Ages
- 18 to 45 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (2 listed)
- Healthy, asymptomatic subjects
- Being physically active
Key exclusion criteria (6 listed)
- Experiencing episodes of acute pain in any part of the body.
- Having chronic pain or a recent history of chronic pain conditions considered resolved within the last 6 months.
- Having a serious illness or inability to perform moderate or intense physical activity.
- Having taken pain relievers, fever reducers, anti-inflammatory drugs (NSAIDs), steroids, opioids, or similar medications in the 24 hours before a session.
- Having consumed alcohol or other psychoactive substances, caffeine, or other stimulants in the 24 hours before a session.
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 |
|---|---|---|
| Seated leg extension machine: low fatigueSeated leg extension machine using 10RM external load for 6 sets of 5 repetitions with180 seconds rest between sets and a cadence of 1:2 second concentric:eccentric | Behavioural | Low fatigue |
| Seated leg extension machine: high fatigueSeated leg extension machine using 10RM external load for 3 sets of 10 repetitions with 180 seconds rest between sets and a cadence of 1:2 second concentric:eccentric | Behavioural | High fatigue |
| Seated leg extension: controlSeated leg extension machine using no external load for 6 sets of 5 repetitions with 180 seconds rest between sets and a cadence of 1:2 second concentric:eccentric | Behavioural | Control |
Primary outcome
Pain pressure threshold
Time frame: Baseline, immediately post-exercise, 30 minutes after exercise
Pain pressure threshold measured with an analogic algometer (Baseline Dolorimeter, MVS In Motion SL, Belgium), in kilograms. These measurements will be taken at a local level (on one of the thighs, over the rectus femoris of the quadriceps, at the midpoint between the pelvic surface and the patella) and at a distance (on the neck over the belly of one of the upper trapezius muscles, at the midpoint between the surface of C7 and the acromion). The pressure will be applied at a rate of 1kg/s and the patient will be instructed to notify the first instance of pain.
Pressure-evoked pain
Time frame: Baseline, immediately post-exercise, 30 minutes after exercise
Pain evoked by a 6kg pressure exerted with an analogic algometer (Baseline Dolorimeter, MVS In Motion SL, Belgium), at a rate of 1kg/s, measured with a numeric rating scale where zero is equivalent to no pain and 10 indicates the worst possible pain. These measurements will be taken at a local level (on one of the thighs, over the rectus femoris of the quadriceps, at the midpoint between the pelvic surface and the patella) and at a distance (on the neck over the belly of one of the upper trapezius muscles, at the midpoint between the surface of C7 and the acromion).
RPE (Rating of Perceived Exertion)
Time frame: Immediately after each set of the training session
Perceived exertion was measured on OMNI-Resistance exercise Scale where 0 is equivalent to no effort and 10 indicates maximal exertion.
sRPE (Session rating of perceived exertion)
Time frame: Monitoring will take place 30 minutes after the final set, ensuring that the exertion from the last set does not interfere with the overall session RPE.
Session Perceived Exertion was measured on a scale where 0 is equivalent to no effort and 10 indicates maximal exertion.
Repetitions in Reserve (RIR)
Time frame: Immediately after each set of the training session.
Using the ERF (Estimated Repetitions to Failure) scale where 0 is equivalent to maximal effort or muscular failure, and higher numbers indicate lower effort. For this purpose, subjects will be asked how many more repetitions they believe they could have performed after each set.
Muscle fatigue
Time frame: Baseline, immediately post-exercise, 30 minutes after exercise
This will be monitored taking into account objective variables (not dependent on the patient's subjective report), through isometric knee extension action tests measured by dynamometry using a portable load cell (Model 620 Tedea-Huntleigh, Vishay Precision Group Inc., Holon, Israel) and Chronojump software (Chronojump Bosco System, Barcelona, Spain). The variables used are the maximal voluntary isometric contraction (MVIC) measured in Newtons (N) and the Rate of Force Development (RFD) which calculates the slope of the force-time curve.
3 secondary outcomes
Kinematic measures
Time frame: During each set of the exercise intervention in all 3 sessions (3 or 6 sets depending on each arm). Total measurement time approximately 3 minutes during a single experimental session (as the device will stop recording during rest periods between sets).
Wellness
Time frame: Prior to each exercise session.
Fitness level
Time frame: Baseline (Day 1)
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 11 May 2026.
- Background: PubMed 39590221Hogge R, Mascheri M, Shurik D, Hanney WJ, Anderson AW. High-Fatigue Dynamic Resistance Exercise Induces Significant Hypoalgesia Effect. J Strength Cond Res. 2025 Feb 1;39(2):165-172. doi: 10.1519/JSC.0000000000004985. Epub 2024 Nov 26.
- Background: PubMed 33062901Vaegter HB, Jones MD. Exercise-induced hypoalgesia after acute and regular exercise: experimental and clinical manifestations and possible mechanisms in individuals with and without pain. Pain Rep. 2020 Sep 23;5(5):e823. doi: 10.1097/PR9.0000000000000823. eCollection 2020 Sep-Oct.
- Background: PubMed 32599154Wewege MA, Jones MD. Exercise-Induced Hypoalgesia in Healthy Individuals and People With Chronic Musculoskeletal Pain: A Systematic Review and Meta-Analysis. J Pain. 2021 Jan;22(1):21-31. doi: 10.1016/j.jpain.2020.04.003. Epub 2020 Jun 26.
- Individual participant dataSharing planned: No
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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.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Seated leg extension machine: low fatigue and Seated leg extension machine: high fatigue in people with Exercise Induced Hypoalgesia and Healthy Adult Volunteer, run by Universidad Miguel Hernandez de Elche at 1 site in Spain.
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 2 inclusion and 6 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 11 May 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 Spain. 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. Some participants in this study may receive a placebo. 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?
Contact Miguel Delicado Miralles, Physiotherapy (+34 679788377, mdelicado@umh.es), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Pain pressure threshold (time frame: Baseline, immediately post-exercise, 30 minutes after exercise). The study lists 6 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 NCT07577622, which also lists 3 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 11 May 2026.