High Intensity Interval Training (Cycling)HIIT-HIFT-FTNCT07180550
Acute Effects of High-intensity Interval Aerobic and Functional Training at Different Intensities
A study testing High-intensity interval training, running, High-intensity interval training, cycling and High-intensity functional training in people with High Intensity Interval Training (Cycling) and High Intensity Interval Training (Running), run by European University Miguel de Cervantes at 1 site in Spain.
Trial summary
Moderate-intensity physical exercise is widely recognized for its health benefits, yet time constraints limit adherence. High-intensity interval training (HIIT) has gained popularity as a more time-efficient alternative, eliciting significant cardiovascular, respiratory, metabolic, and neuromuscular responses. Read more about this study
- Who is it for?
- Ages 18 to 100 yearsHealthy volunteers can take part
- Conditions the study is for
- High Intensity Interval Training (Cycling), High Intensity Interval Training (Running), High Intensity Functional Training
- What is being tested?
- High-intensity interval training, running, High-intensity interval training, cycling and High-intensity functional training
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 27 participants
- Where
- 1 siteSpain
- Study dates
- 12 Oct 2025to 31 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 18 to 100 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Be 18 years of age or older.
- Have at least 6 months of experience in strength training with intensities greater than 75% of one maximum repetition (1-RM).
- Be classified as active according to the International Physical Activity Questionnaire (IPAQ) score.
Who cannot join
- Musculoskeletal injury within the 6 months prior to the first visit to the laboratory.
- Recent major surgery (<3 months).
- Having a medical condition in which physical activity is contraindicated (assessed with the Physical Activity Readiness Questionnaire, PAR-Q+).
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Susana López Ortiz, PhD contact
Spain1 site, 1 recruiting
- Recruiting
Miguel de Cervantes European University
Valladolid, Valladolid, 47012
Francisco Javier Gutiérrez Pecharromán, +34 983001000 ext. 22293, dit@uemc.es
Susana López-Ortiz, PhD, +34 983001000 ext. 22292, slopezo@uemc.es
About this study
Official title: Evaluation of the Acute Effects of High-intensity Interval Aerobic Training, Moderate- and High-intensity Functional Training, and Moderate-intensity Functional Training
Moderate-intensity physical exercise is widely recognized for its health benefits, yet time constraints limit adherence. High-intensity interval training (HIIT) has gained popularity as a more time-efficient alternative, eliciting significant cardiovascular, respiratory, metabolic, and neuromuscular responses. More recently, functional strength exercises have been integrated into high-intensity training, leading to high-intensity functional training (HIFT) and moderate-intensity functional training (MIFT). However, the acute physiological responses to these modalities remain underexplored compared to traditional HIIT (running or cycling) and strength training. This study aims to assess and compare the acute cardiovascular, metabolic, and neuromuscular responses of HIFT, MIFT, HIIT, and traditional strength training in healthy, physically active adults to inform their potential application in special populations.
Read the detailed description
Moderate-intensity physical exercise has long been a cornerstone in promoting health and well-being. However, despite its well-documented benefits, an exclusive focus on this training modality may overlook some important limitations. One such limitation is the challenge of dedicating sufficient time to physical activity to achieve health and fitness goals. Given this constraint, recent years have witnessed a significant shift in training modalities, moving away from continuous moderate-intensity exercise approaches [e.g., 55-70% of peak heart rate (HRpeak) or 40-60% of maximal oxygen uptake (VO₂max)] toward higher-intensity interval training protocols (e.g., >90% HRpeak or >85% VO₂max), thereby enhancing time efficiency and enjoyment for practitioners.
In this context, the most common type of training is high-intensity interval training (HIIT). HIIT consists of performing brief, high-intensity cyclic and continuous efforts (e.g., running or cycling) separated by predefined rest periods while using a single exercise modality. These short efforts (e.g., 1 to 4 minutes) at high intensity, whether cycling or running, elicit substantial cardiovascular, respiratory, metabolic, and neuromuscular stimuli, which can persist for hours after the workout.
Recently, this training approach has incorporated functional strength exercises-movements that mimic natural movement patterns and have practical applications in daily life-performed at high intensity [e.g., >75% of one-repetition maximum (1RM)] and following a circuit-based exercise organization (i.e., performing one exercise after another rather than using simple sets and pauses), a modality commonly referred to as high-intensity functional training (HIFT). Reducing the intensity of prescribed functional exercises (e.g., 60% 1RM) brings the training program closer to the demands of daily activities, a modality commonly known as moderate-intensity functional training (MIFT). However, both HIFT and MIFT define their intensity theoretically, based on the relative intensity concerning the maximum dynamic concentric strength that individuals can develop in each exercise (%1RM). Meanwhile, the cardiovascular, respiratory, metabolic, and neuromuscular demands of these methodologies remain largely unexplored compared to running-based HIIT (HIIT-R), cycling-based HIIT (HIIT-C), and traditional strength training with moderate (M-FT) and high (H-FT) loads in healthy, physically active adults. Therefore, before these methods can be applied to special populations (e.g., individuals with chronic cardiovascular or respiratory diseases, cancer, or older adults), it is essential to first understand their acute response in healthy, physically active individuals.
- Conditions
- High Intensity Interval Training (Cycling), High Intensity Interval Training (Running), High Intensity Functional Training, Moderate Intensity Functional Training, High Intensity Traditional Strength Training, Moderate Intensity Traditional Strength Training
- Being tested
- High-intensity interval training, running, High-intensity interval training, cycling, High-intensity functional training, Moderate-intensity functional training, Moderate intensity traditional strength training
- Keywords
- Metabolic demand, Oxygen consumption, Heart rate variability, Interval training, Strength training
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
High-intensity interval training, runningOther
Six sets of 2-minute runs will be performed at an intensity of 90-95% of the maximal aerobic speed (MAS) on a treadmill. The recovery between each set will be 2 minutes, during which the subject will walk at an intensity of 50-60% of MAS.
High-intensity interval training, cyclingOther
Six sets of 2-minute cycling will be performed at an intensity of 90-95% of the maximal heart rate on a stationary bike. The recovery between each set will be 2 minutes, during which the subject will cycle at an intensity of 50-60% of maximal heart rate.
High-intensity functional trainingOther
Three sets of six repetitions will be performed at 80% of the one repetition-maximum (1-RM) for six exercises. The recovery between exercises will be the minimum time required to switch from one exercise to the next, and between sets, it will be two minutes. Participants will be instructed to move the load as quickly as possible during each repetition.
Moderate-intensity functional trainingOther
Three sets of six repetitions will be performed at 60% of the 1-RM for six exercises. The recovery between exercises will be the minimum time required to switch from one exercise to the next, and between sets, it will be two minutes. Participants will be instructed to move the load as quickly as possible during each repetition.
Moderate intensity traditional strength trainingOther
Three sets of six repetitions will be performed at 60% of the 1-RM for six exercises. The recovery after each set will be two minutes of passive rest. Participants will be instructed to move the load as quickly as possible during each repetition.
High intensity traditional strength trainingOther
Three sets of six repetitions will be performed at 80% of the 1-RM for six exercises. The recovery after each set will be two minutes of passive rest. Participants will be instructed to move the load as quickly as possible during each repetition.
| Study group | Role | What they receive |
|---|---|---|
| High-intensity interval training (running) | Experimental | Participants will perform a high-intensity interval training based on six sets of 2-minute runs at an intensity of 90-95% of the maximal aerobic speed (MAS) on a treadmill. The recovery between each set will be 2 minutes, during which the subject will walk at an intensity of 50-60% of MAS. Receives: Other: High-intensity interval training, running |
| High-intensity interval training (cycling) | Experimental | Participants will perform a high-intensity interval training based on six sets of 2-minute cycling will be performed at an intensity of 90-95% of the maximal heart rate on a stationary bike. The recovery between each set will be 2 minutes, during which the subject will cycle at an intensity of 50-60% of maximal heart rate. Receives: Other: High-intensity interval training, cycling |
| High-intensity functional training | Experimental | Participants will perform a high-intensity functional training based on three sets of six repetitions will be performed at 80% of the one repetition maximum (1-RM) for six exercises. The recovery between exercises will be the minimum time required to switch from one exercise to the next, and between sets, it will be two minutes. Participants will be instructed to move the load as quickly as possible during each repetition. Receives: Other: High-intensity functional training |
| Moderate-intensity functional training | Experimental | Participants will perform a moderate-intensity functional training based on three sets of six repetitions will be performed at 60% of the 1-RM for six exercises. The recovery between exercises will be the minimum time required to switch from one exercise to the next, and between sets, it will be two minutes. Participants will be instructed to move the load as quickly as possible during each repetition. Receives: Other: Moderate-intensity functional training |
| High-intensity traditional training | Experimental | Participants will perform a high-intensity traditional training based on three sets of six repetitions will be performed at 80% of the 1-RM for six exercises. The recovery after each set will be two minutes of passive rest. Participants will be instructed to move the load as quickly as possible during each repetition. Receives: Other: High intensity traditional strength training |
| Moderate-intensity traditional training | Experimental | Participants will perform a high-intensity traditional training based on three sets of six repetitions will be performed at 60% of the 1-RM for six exercises. The recovery after each set will be two minutes of passive rest. Participants will be instructed to move the load as quickly as possible during each repetition. Receives: Other: Moderate intensity traditional strength training |
What is being measured
The primary outcome is the main question the study is designed to answer.
Heart rate variability
The heart rate variability (HRV) of the participants will be assessed by monitoring their heart rate, which reflects the variation in the intervals between heartbeats (R-R intervals). This measure is a useful tool in monitoring patient health, as it estimates the balance between the sympathetic and parasympathetic activity of the autonomic nervous system. To evaluate heart rate variability, a Polar H10 heart rate monitor (Polar Electro Oy, Kempele, Finland) and a mobile application, specifically Elite HRV, will be used. Heart rate variability will be monitored daily during the week leading up to the initial assessment visits. Participants will be instructed to take the measurement for the first 5 minutes upon waking and while fasting.
Subsequently, heart rate variability will be assessed immediately before each training condition, as well as immediately after, at 2, 24, 48, and 72 hours after finishing each training condition.
Measured: Week 0 (baseline), Weeks 1-4 (during intervention and 24, 48, and 72 hours post-intervention)
Secondary outcomes (6)
Post-exercise oxygen debt
The oxygen debt (EPOC) will be calculated every minute during the 12 minutes following the completion of exercise using the following formula: EPOC (L·min-¹) = oxygen consumption (VO2) post-exercise (L·min-¹) - VO2 at rest (L·min-¹). Subsequently, EPOC will be converted into energy expenditure, using the conversion of 1L of O2 = 4.64 kcal, to exclude the rapid glycolytic resynthesis of adenosine triphosphate (ATP) as part of the conversion of O2 consumption into energy expenditure (EE).
Measured: Weeks 2-4 (after every intervention session)
Delayed onset muscle soreness
This will be recorded using a visual analog scale, with a score ranging from 0 (no pain) to 10 (worst possible pain), immediately after the exercise and at 24, 48, and 72 hours after completing the training session. To quantify the pain and standardize the measurements, participants will be asked to perform 5 rapid repetitions of sitting down and standing up from a chair, as well as 5 rapid push-up repetitions, after which they will respond to the question, "How sore are your legs/arms?".
Measured: Weeks 2-4 (24, 48, and 72 hours post-intervention)
Satisfaction with the type of training
It will be evaluated at the end of each session using a numerical scale from 0 to 10, where the highest score indicates maximum satisfaction with the type of training.
Measured: Weeks 2-4 (right after every intervention session and 24 hours post-intervention)
Subjective post-exercise fatigue
It will be measured using the perceived fatigue scale (ROF). This is a numerical scale that ranges from 0 (no fatigue) to 10 (total fatigue or exhaustion), with five descriptors and five diagrams to help the individual understand the scale and make an assessment. This evaluation will be conducted immediately after the exercise session and 24 hours after completion.
Measured: Weeks 2-4 (right after every intervention session and 24 hours post-intervention)
Perceived effort
It will be monitored during the six experimental conditions using the Rate of Perceived Exertion (RPE CR-10) scale. The RPE will be recorded after each set or circuit round. Immediately after completing the last set of each condition, participants will be asked to indicate their perceived effort for the entire session. Subsequently, it will be recorded at 24, 48, and 72 hours after the completion of each condition.
Measured: Weeks 2-4 (right after every intervention session and 24, 48, and 72 hours post-intervention)
Gas exchange analysis
The values of mean and peak gas exchange (ml·kg-1·min-1) during the intervention sessions. The gas analyzer that will be used in this study (Cortex Metalyzer 3B, Leipzig, Germany).
Measured: Weeks 2-4 (during intervention sessions)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted18 Sep 2025
- Study start12 Oct 2025
- Primary completion1 Jan 2027 (estimated)
- Study completion31 Jan 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for High Intensity Interval Training (Cycling)Studies 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
- Other
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- Quasi-experimental, crossover interventional study
- Masking
- Single blind
- Who is masked
- Investigator
- Enrolment
- 27 participants (estimated)
Sponsor and investigators
- Lead sponsor
- European University Miguel de Cervantes
- Sponsor type
- University, hospital or other
- Collaborators
- Hospital Clínico Universitario de Valladolid
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07180550
- Sponsor's protocol ID
- PI-DOC008-HIIT-HIFT-FT
- Acronym
- HIIT-HIFT-FT
- Status last verified
- Mar 2026
- First submitted
- 9 Sep 2025
- Last updated
- 10 Mar 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 10 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Evaluation of the Acute Effects of High-intensity Interval Aerobic Training, Moderate- and High-intensity Functional Training, and Moderate-intensity Functional Training
- ClinicalTrials.gov ID
- NCT07180550
- Acronym / sponsor ID
- HIIT-HIFT-FT / PI-DOC008-HIIT-HIFT-FT
- Conditions
- High Intensity Interval Training (Cycling), High Intensity Interval Training (Running), High Intensity Functional Training, Moderate Intensity Functional Training, High Intensity Traditional Strength Training, Moderate Intensity Traditional Strength Training
- Keywords
- Metabolic demand, Oxygen consumption, Heart rate variability, Interval training, Strength training
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 27 participants (estimated)
- Lead sponsor
- European University Miguel de CervantesUniversity, hospital or other
- Collaborators
- Hospital Clínico Universitario de Valladolid
- Study start
- 12 Oct 2025 (actual)
- Primary completion
- 1 Jan 2027 (estimated)
- Study completion
- 31 Jan 2027 (estimated)
- First posted
- 18 Sep 2025 (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.
Moderate-intensity physical exercise is widely recognized for its health benefits, yet time constraints limit adherence. High-intensity interval training (HIIT) has gained popularity as a more time-efficient alternative, eliciting significant cardiovascular, respiratory, metabolic, and neuromuscular responses. More recently, functional strength exercises have been integrated into high-intensity training, leading to high-intensity functional training (HIFT) and moderate-intensity functional training (MIFT). However, the acute physiological responses to these modalities remain underexplored compared to traditional HIIT (running or cycling) and strength training. This study aims to assess and compare the acute cardiovascular, metabolic, and neuromuscular responses of HIFT, MIFT, HIIT, and traditional strength training in healthy, physically active adults to inform their potential application in special populations.
Detailed description
Moderate-intensity physical exercise has long been a cornerstone in promoting health and well-being. However, despite its well-documented benefits, an exclusive focus on this training modality may overlook some important limitations. One such limitation is the challenge of dedicating sufficient time to physical activity to achieve health and fitness goals. Given this constraint, recent years have witnessed a significant shift in training modalities, moving away from continuous moderate-intensity exercise approaches [e.g., 55-70% of peak heart rate (HRpeak) or 40-60% of maximal oxygen uptake (VO₂max)] toward higher-intensity interval training protocols (e.g., >90% HRpeak or >85% VO₂max), thereby enhancing time efficiency and enjoyment for practitioners.
In this context, the most common type of training is high-intensity interval training (HIIT). HIIT consists of performing brief, high-intensity cyclic and continuous efforts (e.g., running or cycling) separated by predefined rest periods while using a single exercise modality. These short efforts (e.g., 1 to 4 minutes) at high intensity, whether cycling or running, elicit substantial cardiovascular, respiratory, metabolic, and neuromuscular stimuli, which can persist for hours after the workout.
Recently, this training approach has incorporated functional strength exercises-movements that mimic natural movement patterns and have practical applications in daily life-performed at high intensity [e.g., >75% of one-repetition maximum (1RM)] and following a circuit-based exercise organization (i.e., performing one exercise after another rather than using simple sets and pauses), a modality commonly referred to as high-intensity functional training (HIFT). Reducing the intensity of prescribed functional exercises (e.g., 60% 1RM) brings the training program closer to the demands of daily activities, a modality commonly known as moderate-intensity functional training (MIFT). However, both HIFT and MIFT define their intensity theoretically, based on the relative intensity concerning the maximum dynamic concentric strength that individuals can develop in each exercise (%1RM). Meanwhile, the cardiovascular, respiratory, metabolic, and neuromuscular demands of these methodologies remain largely unexplored compared to running-based HIIT (HIIT-R), cycling-based HIIT (HIIT-C), and traditional strength training with moderate (M-FT) and high (H-FT) loads in healthy, physically active adults. Therefore, before these methods can be applied to special populations (e.g., individuals with chronic cardiovascular or respiratory diseases, cancer, or older adults), it is essential to first understand their acute response in healthy, physically active individuals.
Study design
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind (investigator)
- Number of arms
- 6
- Model description
- Quasi-experimental, crossover interventional study
| Arm | Type | Receives |
|---|---|---|
| High-intensity interval training (running) | Experimental | Other: High-intensity interval training, runningParticipants will perform a high-intensity interval training based on six sets of 2-minute runs at an intensity of 90-95% of the maximal aerobic speed (MAS) on a treadmill. The recovery between each set will be 2 minutes, during which the subject will walk at an intensity of 50-60% of MAS. |
| High-intensity interval training (cycling) | Experimental | Other: High-intensity interval training, cyclingParticipants will perform a high-intensity interval training based on six sets of 2-minute cycling will be performed at an intensity of 90-95% of the maximal heart rate on a stationary bike. The recovery between each set will be 2 minutes, during which the subject will cycle at an intensity of 50-60% of maximal heart rate. |
| High-intensity functional training | Experimental | Other: High-intensity functional trainingParticipants will perform a high-intensity functional training based on three sets of six repetitions will be performed at 80% of the one repetition maximum (1-RM) for six exercises. The recovery between exercises will be the minimum time required to switch from one exercise to the next, and between sets, it will be two minutes. Participants will be instructed to move the load as quickly as possible during each repetition. |
| Moderate-intensity functional training | Experimental | Other: Moderate-intensity functional trainingParticipants will perform a moderate-intensity functional training based on three sets of six repetitions will be performed at 60% of the 1-RM for six exercises. The recovery between exercises will be the minimum time required to switch from one exercise to the next, and between sets, it will be two minutes. Participants will be instructed to move the load as quickly as possible during each repetition. |
| High-intensity traditional training | Experimental | Other: High intensity traditional strength trainingParticipants will perform a high-intensity traditional training based on three sets of six repetitions will be performed at 80% of the 1-RM for six exercises. The recovery after each set will be two minutes of passive rest. Participants will be instructed to move the load as quickly as possible during each repetition. |
| Moderate-intensity traditional training | Experimental | Other: Moderate intensity traditional strength trainingParticipants will perform a high-intensity traditional training based on three sets of six repetitions will be performed at 60% of the 1-RM for six exercises. The recovery after each set will be two minutes of passive rest. Participants will be instructed to move the load as quickly as possible during each repetition. |
Who may qualify
- Ages
- 18 to 100 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Be 18 years of age or older.
- Have at least 6 months of experience in strength training with intensities greater than 75% of one maximum repetition (1-RM).
- Be classified as active according to the International Physical Activity Questionnaire (IPAQ) score.
Key exclusion criteria (3 listed)
- Musculoskeletal injury within the 6 months prior to the first visit to the laboratory.
- Recent major surgery (<3 months).
- Having a medical condition in which physical activity is contraindicated (assessed with the Physical Activity Readiness Questionnaire, PAR-Q+).
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 |
|---|---|---|
| High-intensity interval training, runningSix sets of 2-minute runs will be performed at an intensity of 90-95% of the maximal aerobic speed (MAS) on a treadmill. The recovery between each set will be 2 minutes, during which the subject will walk at an intensity of 50-60% of MAS. | Other | High-intensity interval training (running) |
| High-intensity interval training, cyclingSix sets of 2-minute cycling will be performed at an intensity of 90-95% of the maximal heart rate on a stationary bike. The recovery between each set will be 2 minutes, during which the subject will cycle at an intensity of 50-60% of maximal heart rate. | Other | High-intensity interval training (cycling) |
| High-intensity functional trainingThree sets of six repetitions will be performed at 80% of the one repetition-maximum (1-RM) for six exercises. The recovery between exercises will be the minimum time required to switch from one exercise to the next, and between sets, it will be two minutes. Participants will be instructed to move the load as quickly as possible during each repetition. | Other | High-intensity functional training |
| Moderate-intensity functional trainingThree sets of six repetitions will be performed at 60% of the 1-RM for six exercises. The recovery between exercises will be the minimum time required to switch from one exercise to the next, and between sets, it will be two minutes. Participants will be instructed to move the load as quickly as possible during each repetition. | Other | Moderate-intensity functional training |
| Moderate intensity traditional strength trainingThree sets of six repetitions will be performed at 60% of the 1-RM for six exercises. The recovery after each set will be two minutes of passive rest. Participants will be instructed to move the load as quickly as possible during each repetition. | Other | Moderate-intensity traditional training |
| High intensity traditional strength trainingThree sets of six repetitions will be performed at 80% of the 1-RM for six exercises. The recovery after each set will be two minutes of passive rest. Participants will be instructed to move the load as quickly as possible during each repetition. | Other | High-intensity traditional training |
Primary outcome
Heart rate variability
Time frame: Week 0 (baseline), Weeks 1-4 (during intervention and 24, 48, and 72 hours post-intervention)
The heart rate variability (HRV) of the participants will be assessed by monitoring their heart rate, which reflects the variation in the intervals between heartbeats (R-R intervals). This measure is a useful tool in monitoring patient health, as it estimates the balance between the sympathetic and parasympathetic activity of the autonomic nervous system. To evaluate heart rate variability, a Polar H10 heart rate monitor (Polar Electro Oy, Kempele, Finland) and a mobile application, specifically Elite HRV, will be used. Heart rate variability will be monitored daily during the week leading up to the initial assessment visits. Participants will be instructed to take the measurement for the first 5 minutes upon waking and while fasting. Subsequently, heart rate variability will be assessed immediately before each training condition, as well as immediately after, at 2, 24, 48, and 72 hours after finishing each training condition.
6 secondary outcomes
Post-exercise oxygen debt
Time frame: Weeks 2-4 (after every intervention session)
Delayed onset muscle soreness
Time frame: Weeks 2-4 (24, 48, and 72 hours post-intervention)
Satisfaction with the type of training
Time frame: Weeks 2-4 (right after every intervention session and 24 hours post-intervention)
Subjective post-exercise fatigue
Time frame: Weeks 2-4 (right after every intervention session and 24 hours post-intervention)
Perceived effort
Time frame: Weeks 2-4 (right after every intervention session and 24, 48, and 72 hours post-intervention)
Gas exchange analysis
Time frame: Weeks 2-4 (during intervention sessions)
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 10 Mar 2026.
- 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.
Susana López Ortiz, PhD contact
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing High-intensity interval training, running, High-intensity interval training, cycling and High-intensity functional training in people with High Intensity Interval Training (Cycling) and High Intensity Interval Training (Running), run by European University Miguel de Cervantes 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 3 inclusion and 3 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: looking for participants now, as of the sponsor's last update on 10 Mar 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. 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 Susana López Ortiz, PhD (983001000, cbaladron@icicor.es), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Heart rate variability (time frame: Week 0 (baseline), Weeks 1-4 (during intervention and 24, 48, and 72 hours post-intervention)). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 10 Mar 2026.