Clinical trial NCT05067426: The 10/7 HIIT Shock Cycle Study: Effectiveness of 10 HIIT Sessions in 7 Days
Official title: The 10/7 HIIT Shock Cycle Study: The Effects of a 7-Day High-Intensity-Interval Training Shock Microcycle on Endurance Performance, Well-Being, Stress and Recovery in Endurance Trained Athletes - Randomized Controlled Trial
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Healthy
Athlete
Performance
Keywords: High-intensity interval training
Microcycle
Endurance training
Load monitoring
Athlete performance
HIT training
Block training
HIT block
Polarized training
Lead sponsor: University of Salzburg
Sponsor class: OTHER
Collaborators: name: Paracelsus Medical University
name: Johannes Gutenberg University Mainz
First posted: 2021-10-05
Enrollment: 33
Sex: ALL
Minimum age (years): 18
Maximum age (years): 45
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Intervention model description: Participants are randomly assigned in either one of 2 intervention groups or a control group (ratio 1:1:1).
Primary purpose: TREATMENT

Brief summary: A randomized, controlled trial to evaluate the effects of two versions of 10 high intensity interval trainings (HIIT) within a 7-day shock microcycle on endurance performance, well-being, health, stress and recovery in trained athletes.

Detailed description: Thirty-six trained endurance athletes will be recruited and randomly assigned to either a "high volume (HIIT-HV)" group, a "low volume (HIIT-LV)" group, or a control group. All participants will be monitored before (9 days), during (7 days), and after (14 days) a 7-day training intervention, for 30 days. Participants in both intervention groups will complete 10 HIIT sessions within the period of 7 days, with an additional 30 minutes of low-intensity training exclusively in HIIT-HV. HIIT sessions consist of aerobic HIIT, i.e., 5x4min at 90-95% of maximal heart rate interspersed by 2.5 min active recovery periods. To determine the effects of the intervention, performance diagnostics, and a 5 kilometer time trial will be conducted before and after the intervention. In addition, participants are closely monitored for general health, stress, fatigue, recovery, neuromuscular performance, executive functions and sleep.

Eligibility criteria: Inclusion Criteria:

* Female or male
* aged 18-45 years
* Proof of physical fitness (e.g. sports medical examination required) for measurements with higher intensities (e.g. endurance tests, competition simulation)
* Competition experience at the national or international level in an endurance sport
* VO2max ≥50ml/kg/min for females; ≥55 ml/kg/min for males or a 5-kilometer (km) time trial performance of ≤ 20:00 min (female), or ≤ 18:30 min (male)

Exclusion Criteria:

* Systemic disease or other known pathology in the organs: heart, lungs, kidney, stomach, spleen, liver, gall bladder, and intestines.
* Evidence of pulmonary disease: forced expiratory volume in one second/forced expiratory volume \< 70% with/without symptoms (cough, sputum) or other evidence of pulmonologic disease.
* Diabetes II.
* Neurological or psychological disease of any kind.
* Currently undergoing medical or psycho-therapeutic treatment.
* Health condition that does not allow regular participation in the training forms (e.g. acute illnesses such as fever or other flu-like infections within the last 7 days before the start of the study), orthopedic diseases, injuries to the muscular, bone, joint or tendon apparatus within the last three months.
* Alcohol or drug abuse.
* Already high training volume with high intensity training (more than 2 weekly training sessions of high-intensity training)

Primary outcomes:
measure: Endurance performance I
timeFrame: 10 to 21 days (assessment is conducted once before the intervention and repeated three times afterwards, i.e. 3, 7 and 14 days after the completion of the intervention)
measure: Endurance performance II
timeFrame: 10 to 21 days (assessment is conducted once before the intervention and repeated three times afterwards, i.e. 3, 7 and 14 days after the completion of the intervention)
measure: Endurance performance III
timeFrame: 20 to 22 days (the assessment is conducted once before, and once after the intervention)
measure: Endurance performance IV
timeFrame: 10 to 21 days (assessment is conducted once before the intervention and repeated three times afterwards, i.e. 3, 7 and 14 days after the completion of the intervention)
measure: Endurance performance V
timeFrame: 10 to 21 days (assessment is conducted once before the intervention and repeated three times afterwards, i.e. 3, 7 and 14 days after the completion of the intervention)
measure: Endurance performance VI
timeFrame: 10 to 21 days (assessment is conducted once before the intervention and repeated three times afterwards, i.e. 3, 7 and 14 days after the completion of the intervention)
Secondary outcomes:
measure: Change of questionnaire scores - well-being
timeFrame: 30 days (questionnaires will be given to participants several times before, during, and after the intervention.)
measure: Change of questionnaire scores - muscular fatigue
timeFrame: 30 days (questionnaires will be given to participants several times before, during, and after the intervention.)
measure: Change of questionnaire scores - vitality
timeFrame: 30 days (questionnaires will be given to participants several times before, during, and after the intervention.)
measure: Change of questionnaire scores - rate of fatigue
timeFrame: 30 days (questionnaires will be given to participants several times before, during, and after the intervention.)
measure: Change of questionnaire scores - sleep quality
timeFrame: 30 days (questionnaires will be given to participants several times before, during, and after the intervention.)
measure: Change of blood count
timeFrame: 30 days (blood is drawn from participants several times before, during, and after the intervention.)
measure: Change of cell-free DNA
timeFrame: 30 days (blood is drawn from participants several times before, during, and after the intervention.)
measure: Change of creatine kinase
timeFrame: 30 days (blood is drawn from participants several times before, during, and after the intervention.)
measure: Change of urea
timeFrame: 30 days (blood is drawn from participants several times before, during, and after the intervention.)
measure: Change of blood lactate
timeFrame: 30 days (blood is drawn from participants several times before, during, and after the intervention.)
measure: Change of cytokines
timeFrame: 30 days (blood is drawn from participants several times before, during, and after the intervention.)
measure: Change of miRNA
timeFrame: 30 days (blood is drawn from participants several times before, during, and after the intervention.)
measure: Change of neuromuscular performance
timeFrame: 30 days (neuromuscular performance is assessed several times before, during, and after the intervention)
measure: Change of body weight
timeFrame: 10 to 21 days (assessment is conducted once before the intervention and repeated three times afterwards, i.e. 3, 7 and 14 days after the completion of the intervention)
measure: Change of fat free mass
timeFrame: 10 to 21 days (assessment is conducted once before the intervention and repeated three times afterwards, i.e. 3, 7 and 14 days after the completion of the intervention)
measure: Change of fat mass
timeFrame: 10 to 21 days (assessment is conducted once before the intervention and repeated three times afterwards, i.e. 3, 7 and 14 days after the completion of the intervention)
measure: Change of forced expiratory volume
timeFrame: 10 to 21 days (assessment is conducted once before the intervention and repeated three times afterwards, i.e. 3, 7 and 14 days after the completion of the intervention)
measure: Change of power output during exercise
timeFrame: 7 days
measure: Change of sleep quality I - GPS watch
timeFrame: 30 days (sleep is assessed several times before, during, and after the intervention)
measure: Change of sleep quality II - ABIOS App
timeFrame: 30 days (sleep is assessed several times before, during, and after the intervention)
measure: Correlations between sleep quality devices
timeFrame: 30 days
measure: Change of parameters recorded by an electrocardiogram - mean heart rate
timeFrame: 30 days (an electrocardiogram is written several times before, during, and after the intervention)
measure: Change of parameters recorded by an electrocardiogram - heart rate variability
timeFrame: 30 days (an electrocardiogram is written several times before, during, and after the intervention)
measure: Change of executive functions - Eriksen flanker task
timeFrame: 30 days (executive functions are tested several times before, during, and after the intervention)
measure: Change of executive functions - 2 back task
timeFrame: 30 days (executive functions are tested several times before, during, and after the intervention)
measure: Cardiac ultrasound
timeFrame: 1 day (this outcome will be determined once before study start)
measure: Adherence to training program
timeFrame: 7 days
Other outcomes:
Locations:
city: Salzburg
country: Austria
facility: University of Salzburg
Study officials:
affiliation: University of Salzburg
name: Thomas Stoeggl, Professor, PhD
role: STUDY_CHAIR
References:
citation: Stoggl TL, Blumkaitis JC, Strepp T, Sareban M, Simon P, Neuberger EWI, Finkenzeller T, Nunes N, Aglas L, Haller N. The Salzburg 10/7 HIIT shock cycle study: the effects of a 7-day high-intensity interval training shock microcycle with or without additional low-intensity training on endurance performance, well-being, stress and recovery in endurance trained athletes-study protocol of a randomized controlled trial. BMC Sports Sci Med Rehabil. 2022 May 7;14(1):84. doi: 10.1186/s13102-022-00456-8.