The 10/7 HIIT Shock Cycle Study: Effectiveness of 10 HIIT Sessions in 7 Days (THESIS)

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

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.

Study Overview

• Status: Completed
• Conditions: Healthy; Performance; Athlete
• Intervention / Treatment: Other: Exercise

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.

• Study Type: Interventional
• Enrollment (Actual): 33
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Austria
  • Salzburg, Austria, 5400
    • University of Salzburg

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 45 years (Adult)
• Accepts Healthy Volunteers: Yes

Description

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)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: HIIT-HV; HIIT-HV - high intensity interval training high volume Participants complete a total of 10 HIIT sessions over a 7-day period consisting of 5 x 4-minute intervals at an intensity of 90-95% of their individual maximum heart rate (HRmax), interspersed with a 2.5-minute active recovery period. Each training session is followed by 30 minutes of low-intensity training (total of 300 minutes of additional low-intensity training during this period).	Other: Exercise; high-intensity interval training sessions
Experimental: HIIT-LV; HIIT- LV - high intensity interval training low volume Participants complete a total of 10 HIIT sessions over a 7-day period consisting of 5 x 4-minute intervals at an intensity of 90-95% of their individual maximum heart rate (HRmax), interspersed with a 2.5-minute active recovery period.	Other: Exercise; high-intensity interval training sessions
No Intervention: Control group; Participants continue with their regular training program.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Endurance performance I	Change of maximal oxygen uptake (VO2max in ml/min/kg) compared to baseline and group	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)
Endurance performance II	Change of peak performance (Ppeak in Watt) compared to baseline and group	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)
Endurance performance III	Change of 5 kilometer time trial performance (in sec) compared to baseline and group	20 to 22 days (the assessment is conducted once before, and once after the intervention)
Endurance performance IV	Change of lactate threshold (in km/h) compared to baseline and group	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)
Endurance performance V	Change of ventilatory thresholds (in km/h) compared to baseline and group	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)
Endurance performance VI	Change of running economy (in ml/min/kg) compared to baseline and group	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 Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change of questionnaire scores - well-being	Change of questionnaire scores compared to baseline and group as determined by a Visual-Analogue-Scale (from 0-100 millimeters). Higher scores indicate poorer well-being.	30 days (questionnaires will be given to participants several times before, during, and after the intervention.)
Change of questionnaire scores - muscular fatigue	Change of questionnaire scores compared to baseline and group as determined by a Visual-Analogue-Scale (from 0-100 millimeters). Higher scores indicate higher degree of fatigue.	30 days (questionnaires will be given to participants several times before, during, and after the intervention.)
Change of questionnaire scores - vitality	Change of questionnaire scores compared to baseline and group as determined by a Likert-Scale (from 0-10). Higher scores indicate higher vitality.	30 days (questionnaires will be given to participants several times before, during, and after the intervention.)
Change of questionnaire scores - rate of fatigue	Change of questionnaire scores compared to baseline and group as determined by a Likert-Scale (from 0-10). Higher scores indicate higher degree of fatigue.	30 days (questionnaires will be given to participants several times before, during, and after the intervention.)
Change of questionnaire scores - sleep quality	Change of questionnaire scores compared to baseline and group as determined by a Likert-Scale (from 1-7). Higher scores indicate poorer sleep.	30 days (questionnaires will be given to participants several times before, during, and after the intervention.)
Change of blood count	Change of blood count concentrations compared to baseline and group	30 days (blood is drawn from participants several times before, during, and after the intervention.)
Change of cell-free DNA	Change of cell-free DNA concentrations compared to baseline and group	30 days (blood is drawn from participants several times before, during, and after the intervention.)
Change of creatine kinase	Change of creatine kinase concentrations compared to baseline and group	30 days (blood is drawn from participants several times before, during, and after the intervention.)
Change of urea	Change of urea concentrations compared to baseline and group	30 days (blood is drawn from participants several times before, during, and after the intervention.)
Change of blood lactate	Change of blood lactate concentrations compared to baseline and group	30 days (blood is drawn from participants several times before, during, and after the intervention.)
Change of cytokines	Change of cytokine concentrations compared to baseline and group	30 days (blood is drawn from participants several times before, during, and after the intervention.)
Change of miRNA	Change of miRNA compared to baseline and group	30 days (blood is drawn from participants several times before, during, and after the intervention.)
Change of neuromuscular performance	Change of neuromuscular performance (counter movement jump height in cm) measured on a contact plate (AMTI, Watertown, USA) compared to baseline and group	30 days (neuromuscular performance is assessed several times before, during, and after the intervention)
Change of body weight	Change of body weight in kg compared to baseline and group	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)
Change of fat free mass	Change of fat free mass in kg compared to baseline and group	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)
Change of fat mass	Change of fat mass in kg compared to baseline and group	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)
Change of forced expiratory volume	Change of forced expiratory volume in liters compared to baseline and group	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)
Change of power output during exercise	Change of power output in Watt (as determined via Stryd, Boulder, USA) during the intervention compared to baseline and group	7 days
Change of sleep quality I - GPS watch	Change of sleep quality compared to baseline and group as determined by a GPS (Global Positioning System) watch	30 days (sleep is assessed several times before, during, and after the intervention)
Change of sleep quality II - ABIOS App	Change of sleep quality compared to baseline and group as determined by the ABIOS (Algorithmik Biodata System) application	30 days (sleep is assessed several times before, during, and after the intervention)
Correlations between sleep quality devices	To determine the correlations between different sleep monitoring devices, i.e. the GPS watch (see outcome 27), the ABIOS system (see outcome 28) and the sleep quality questionnaire (see outcome 11)	30 days
Change of parameters recorded by an electrocardiogram - mean heart rate	Change of mean heart rate compared to baseline and group	30 days (an electrocardiogram is written several times before, during, and after the intervention)
Change of parameters recorded by an electrocardiogram - heart rate variability	Change of heart rate variability (root mean sum of squared distance in ms) compared to baseline and group	30 days (an electrocardiogram is written several times before, during, and after the intervention)
Change of executive functions - Eriksen flanker task	Change of executive functions compared to baseline and group. This is recorded through a modified Eriksen flanker task consisting of 108 images showing five white arrows on a black screen.	30 days (executive functions are tested several times before, during, and after the intervention)
Change of executive functions - 2 back task	Change of executive functions compared to baseline and group. This is assessed through a 2-back task showing dots on a dice, numbers and geometrical figures.	30 days (executive functions are tested several times before, during, and after the intervention)
Cardiac ultrasound	Description of an athlete cohort regarding cardiac chamber volume (in ml, determined via EPIQ CVX, X5-1, Philips Healthcare, Andover, MA, USA)	1 day (this outcome will be determined once before study start)
Adherence to training program	Adherence to the HIIT training programs (determined as the ratio of training sessions performed to prescribed training sessions). This is determined by the researchers by checking the training data of the athletes. For example, if 9 out of 10 sessions were performed, this means 90% adherence.	7 days

Collaborators and Investigators

• Sponsor: University of Salzburg
• Collaborators: Johannes Gutenberg University Mainz; Paracelsus Medical University
• Investigators: Study Chair: Thomas Stoeggl, Professor, PhD, University of Salzburg

Publications and helpful links

General Publications

• 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.

Study record dates

Study Major Dates

• Study Start (Actual): August 15, 2021
• Primary Completion (Actual): December 31, 2022
• Study Completion (Actual): December 31, 2022

Study Registration Dates

• First Submitted: September 6, 2021
• First Submitted That Met QC Criteria: September 23, 2021
• First Posted (Actual): October 5, 2021

Study Record Updates

• Last Update Posted (Estimated): January 31, 2024
• Last Update Submitted That Met QC Criteria: January 30, 2024
• Last Verified: January 1, 2024

More Information

Terms related to this study

• Keywords: High-intensity interval training; Endurance training; Microcycle; Load monitoring; Athlete performance; HIT training; Block training; HIT block; Polarized training
• Other Study ID Numbers: NHaller

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No