Pan African Clinical Trials Registry
South African Medical Research Council, South African Cochrane Centre
PO Box 19070, Tygerberg, 7505, South Africa
Telephone: +27 21 938 0835 or +27 21 938 0967
Email: pactradmin@mrc.ac.za Website: pactr.samrc.ac.za
Trial no.: PACTR202507832558818 Date of Registration: 24/07/2025
Trial Status: Retrospective registration - This trial was registered after enrolment of the first participant
TRIAL DESCRIPTION
Public title High-intensity interval running enhances components of physical fitness but not parathyroid hormone levels in healthy adolescent males
Official scientific title High-intensity interval running enhances components of physical fitness but not parathyroid hormone levels in healthy adolescent males
Brief summary describing the background and objectives of the trial High-intensity interval training (HIIT) is a time-efficient method to improve youth fitness. Adolescence, a key phase for bone and hormonal development, may be sensitive to exercise-induced changes in hormones like parathyroid hormone (PTH). However, the effects of HIIT on PTH levels during this phase remain unclear. The purpose of the current study was to evaluate the effects of HIIT on PTH levels and physical fitness measures including jumping and sprinting performance, and cardiorespiratory-fitness in adolescent males. Twenty-eight healthy adolescent males (age, 14.9±0.74 yrs.) were randomly assigned to two groups randomly: HIIT (n=15) or control (n=13) groups. The HIIT training program was achieved three times per week over a 10-week period. Anthropometric parameters, physical performance [cardiorespiratory-fitness (maximal-oxygen-consumption), sprint-ability, squat-jump (SJ), countermovement-jump (CMJ), five-jump test (FJT)] and plasma PTH concentrations were assessed before- and after-intervention. No significant between group baseline differences were noted. Significant “time*group” interactions were found all physical fitness measures (P<0.05), but not for anthropometric parameters or PTH levels. The HIIT program resulted in an increase in maximal-oxygen-consumption (P<0.001), SJ (P=0.003), CMJ (P=0.006), FJT (P=0.001), and a decrease in 5-m (P<0.001), 10-m (P<0.001), 20-m (P=0.001) and 30-m (P=0.002) sprint times. However, no significant change was detected for PTH levels in response to 10-week intervention. Following 10-week HIIT program, physical fitness had improved, but no significant change had occurred for PTH levels in adolescent males. Further research is needed to better understand the interaction between PTH and other bone-related biochemical markers (e.g., ionized calcium, 25-hydroxyvitamin D or osteocalcin) in response to varying HIIT durations and intensities during adolescence.
Type of trial RCT
Acronym (If the trial has an acronym then please provide)
Disease(s) or condition(s) being studied Musculoskeletal Diseases,Respiratory
Sub-Disease(s) or condition(s) being studied
Purpose of the trial Education /Training
Anticipated trial start date 23/09/2024
Actual trial start date 01/10/2024
Anticipated date of last follow up 16/12/2024
Actual Last follow-up date 23/12/2024
Anticipated target sample size (number of participants) 34
Actual target sample size (number of participants) 28
Recruitment status Active, not recruiting
Publication URL
Secondary Ids Issuing authority/Trial register
STUDY DESIGN
Intervention assignment Allocation to intervention If randomised, describe how the allocation sequence was generated Describe how the allocation sequence/code was concealed from the person allocating the participants to the intervention arms Masking If masking / blinding was used
Factorial: participants randomly allocated to either no, one, some or all interventions simultaneously Randomised Simple randomization using a randomization table created by a computer software program Allocation was determined by the holder of the sequence who is situated off site Masking/blinding used Participants
INTERVENTIONS
Intervention type Intervention name Dose Duration Intervention description Group size Nature of control
Experimental Group HIIT group 30 session, 30-35 min per session 10 weeks (three sessions per week) The HIIT program consisted of high-intensity interval exercise sessions performed three times per week on nonconsecutive days (i.e., Tuesday, Thursday and Saturday) for a period of 10 consecutive weeks. The training protocol was carried out as previously described by Ouerghi et al. (2017a,b) and Buchan et al. (2013) in young males. The HIIT period commenced 2 days after the pretesting procedure. Each training session was started by a standardized 15-min warm-up consisting of light aerobic exercise followed by high-intensity interval runs. The protocol consisted of three series of 4-8 repetitions of 30-s of work at 100-110% of MAS and 30-s of active recovery at 50% of MAS. Participants were required to increase the number of repetitions from 4 to 8, and intensity from 100 to 110 % of MAS. Each training sessions ended with a 10-min cool-down followed by 5 min of static stretching. 15
Control Group No intervention maintained their normal daily activity 10 weeks maintained their normal daily activity 13 Active-Treatment of Control Group
ELIGIBILITY CRITERIA
List inclusion criteria List exclusion criteria Age Category Minimum age Maximum age Gender
- male sex - age from 14 to 16 years - classified as normal-weight according to the World Health Organization (WHO) child growth standards for BMI (normal-weight: BMI ≤ 85th percentile) - usual physical activity consisting of weekly two-hour physical education lessons - one football training session/week in the middle school's sports association - parental approval. - consent retirement - non-compliance to the training program - participation in physical training at the time of the study or within the past 6 months (except physical education class and middle school sports association football training) - current or recent (within 3 months) dietary restriction or dietary supplementation - incomplete data Adolescent: 13 Year(s)-17 Year(s) 14 Year(s) 16 Year(s) Male
ETHICS APPROVAL
Has the study received appropriate ethics committee approval Date the study will be submitted for approval Date of approval Name of the ethics committee
Yes 03/09/2024 Ethic committee of Research Unit Sport Sciences Health and Movement of High Institute of Sport and Physical Education of Kef
Ethics Committee Address
Street address City Postal code Country
University of Jendouba Higher Institute of Sport and Physical Education of Kef Boulifa University Campus Kef Tunisia Kef 7100 Tunisia
OUTCOMES
Type of outcome Outcome Timepoint(s) at which outcome measured
Primary Outcome The 10-weeks HIIT program significantly enhanced fitness components, including jumping and sprinting performance, and maximal oxygen consumption in healthy adolescent males Pre and post 10 weeks intervention
Secondary Outcome No significant change was detected for Parathyroid hormone levels in response to 10-week intervention. Pre and post 10 weeks intervention
RECRUITMENT CENTRES
Name of recruitment centre Street address City Postal code Country
Abou Kacem Chebbi Middle School Dahmani, El Kef Governorate, Tunisia Dahmani 7170 Tunisia
FUNDING SOURCES
Name of source Street address City Postal code Country
Research Unit Sport Sciences Health and Movement of High Institute of Sport and Physical Education of Kef Boulifa University Campus 7100 Kef Tunisia Kef 7100 Tunisia
SPONSORS
Sponsor level Name Street address City Postal code Country Nature of sponsor
Primary Sponsor NO NO 0000 000 Tunisia Individual
COLLABORATORS
Name Street address City Postal code Country
Nejmeddine Ouerghi Dahmani Dahmani 7170 Tunisia
Wissal Abassi Dahmani Dahmani 7170 Tunisia
Jebabli Nidhal City Jebabli Tajerouine 7150 Tunisia
CONTACT PEOPLE
Role Name Email Phone Street address
Principal Investigator Nejmeddine Ouerghi najm_ouerghi@hotmail.com 0021625300232 Dahmani
City Postal code Country Position/Affiliation
Dahmani 7170 Tunisia PhD researcher in High Institute of Sportand Physical Education of Kef
Role Name Email Phone Street address
Public Enquiries Abassi Wissal wissalabassi93@gmail.com 0021693304684 Kalaat Senan
City Postal code Country Position/Affiliation
Kalaat Senan 7130 Tunisia PhD researcher in High Institute of Sportand Physical Education of Kef
Role Name Email Phone Street address
Scientific Enquiries Nidhal Jebabli jnidhal@gmail.com 00216253160 City Jebabli
City Postal code Country Position/Affiliation
Tajerouine 7150 Tunisia PhD researcher in High Institute of Sportand Physical Education of Kef
REPORTING
Share IPD Description Additional Document Types Sharing Time Frame Key Access Criteria
Yes As part of our commitment to transparency and scientific collaboration, we plan to share the individual trial participant data in an anonymized manner. In accordance with the World Health Organization's (WHO) data sharing policy, this IPD sharing statement aims to promote the replicability of study results and facilitate further analysis by the scientific community. The individual trial participant data collected for this study includes demographic information, medical history, treatment interventions, and clinical outcomes. All personally identifiable information has been rigorously removed or anonymized to protect the confidentiality of the participants. Only anonymous identification codes are used to link the data to individual participants. Statistical Analysis Plan,Study Protocol The IPD of this study areavailable from any demands open
URL Results Available Results Summary Result Posting Date First Journal Publication Date
Yes 13/07/2025
Result Upload 1: Result Upload 2: Result Upload 3: Result Upload 4: Result Upload 5:
Result - 13/07/2025
Result URL Hyperlinks Link To Protocol
Result URL Hyperlinks
Changes to trial information
Section Name Field Name Date Reason Old Value Updated Value
Trial Information Trial description 17/07/2025 Thank you for your feedback. We have now included the objective of the study in lines 3–4, immediately following the background High-intensity interval training (HIIT) is a time-efficient method to improve youth fitness. Adolescence, a key phase for bone and hormonal development, may be sensitive to exercise-induced changes in hormones like parathyroid hormone (PTH). However, the effects of HIIT on PTH levels during this phase remain unclear. This study aimed to evaluate the effects of HIIT on PTH levels and physical fitness measures including jumping and sprinting performance, and cardiorespiratory-fitness in adolescent males. Twenty-eight healthy adolescent males (age, 14.9±0.74 yrs.) were randomly assigned to two groups randomly: HIIT (n=15) or control (n=13) groups. The HIIT training program was achieved three times per week over a 10-week period. Anthropometric parameters, physical performance [cardiorespiratory-fitness (maximal-oxygen-consumption), sprint-ability, squat-jump (SJ), countermovement-jump (CMJ), five-jump test (FJT)] and plasma PTH concentrations were assessed before- and after-intervention. No significant between group baseline differences were noted. Significant “time*group” interactions were found all physical fitness measures (P<0.05), but not for anthropometric parameters or PTH levels. The HIIT program resulted in an increase in maximal-oxygen-consumption (P<0.001), SJ (P=0.003), CMJ (P=0.006), FJT (P=0.001), and a decrease in 5-m (P<0.001), 10-m (P<0.001), 20-m (P=0.001) and 30-m (P=0.002) sprint times. However, no significant change was detected for PTH levels in response to 10-week intervention. No significant variations were detected for all variables in the control group. Following 10-week HIIT program, physical fitness had improved, but no significant change had occurred for PTH levels in adolescent males. Further research is needed to better understand the interaction between PTH and other bone-related biochemical markers (e.g., ionized calcium, 25-hydroxyvitamin D or osteocalcin) in response to varying HIIT durations and intensities during adolescence. High-intensity interval training (HIIT) is a time-efficient method to improve youth fitness. Adolescence, a key phase for bone and hormonal development, may be sensitive to exercise-induced changes in hormones like parathyroid hormone (PTH). However, the effects of HIIT on PTH levels during this phase remain unclear. The purpose of the current study was to evaluate the effects of HIIT on PTH levels and physical fitness measures including jumping and sprinting performance, and cardiorespiratory-fitness in adolescent males. Twenty-eight healthy adolescent males (age, 14.9±0.74 yrs.) were randomly assigned to two groups randomly: HIIT (n=15) or control (n=13) groups. The HIIT training program was achieved three times per week over a 10-week period. Anthropometric parameters, physical performance [cardiorespiratory-fitness (maximal-oxygen-consumption), sprint-ability, squat-jump (SJ), countermovement-jump (CMJ), five-jump test (FJT)] and plasma PTH concentrations were assessed before- and after-intervention. No significant between group baseline differences were noted. Significant “time*group” interactions were found all physical fitness measures (P<0.05), but not for anthropometric parameters or PTH levels. The HIIT program resulted in an increase in maximal-oxygen-consumption (P<0.001), SJ (P=0.003), CMJ (P=0.006), FJT (P=0.001), and a decrease in 5-m (P<0.001), 10-m (P<0.001), 20-m (P=0.001) and 30-m (P=0.002) sprint times. However, no significant change was detected for PTH levels in response to 10-week intervention. Following 10-week HIIT program, physical fitness had improved, but no significant change had occurred for PTH levels in adolescent males. Further research is needed to better understand the interaction between PTH and other bone-related biochemical markers (e.g., ionized calcium, 25-hydroxyvitamin D or osteocalcin) in response to varying HIIT durations and intensities during adolescence.
Section Name Field Name Date Reason Old Value Updated Value
Trial Information Trial description 17/07/2025 Thank you to the Trial Reviewer for this comment. We indicated the objective of the study (line 3 - 4) after the Background High-intensity interval training (HIIT) is a time-efficient method to improve youth fitness. Adolescence, a key phase for bone and hormonal development, may be sensitive to exercise-induced changes in hormones like parathyroid hormone (PTH). However, the effects of HIIT on PTH levels during this phase remain unclear. The purpose of the current study was to evaluate the effects of HIIT on PTH levels and physical fitness measures including jumping and sprinting performance, and cardiorespiratory-fitness in adolescent males. Twenty-eight healthy adolescent males (age, 14.9±0.74 yrs.) were randomly assigned to two groups randomly: HIIT (n=15) or control (n=13) groups. The HIIT training program was achieved three times per week over a 10-week period. Anthropometric parameters, physical performance [cardiorespiratory-fitness (maximal-oxygen-consumption), sprint-ability, squat-jump (SJ), countermovement-jump (CMJ), five-jump test (FJT)] and plasma PTH concentrations were assessed before- and after-intervention. No significant between group baseline differences were noted. Significant “time*group” interactions were found all physical fitness measures (P<0.05), but not for anthropometric parameters or PTH levels. The HIIT program resulted in an increase in maximal-oxygen-consumption (P<0.001), SJ (P=0.003), CMJ (P=0.006), FJT (P=0.001), and a decrease in 5-m (P<0.001), 10-m (P<0.001), 20-m (P=0.001) and 30-m (P=0.002) sprint times. However, no significant change was detected for PTH levels in response to 10-week intervention. Following 10-week HIIT program, physical fitness had improved, but no significant change had occurred for PTH levels in adolescent males. Further research is needed to better understand the interaction between PTH and other bone-related biochemical markers (e.g., ionized calcium, 25-hydroxyvitamin D or osteocalcin) in response to varying HIIT durations and intensities during adolescence. High-intensity interval training (HIIT) is a time-efficient method to improve youth fitness. Adolescence, a key phase for bone and hormonal development, may be sensitive to exercise-induced changes in hormones like parathyroid hormone (PTH). However, the effects of HIIT on PTH levels during this phase remain unclear. The purpose of the current study was to evaluate the effects of HIIT on PTH levels and physical fitness measures including jumping and sprinting performance, and cardiorespiratory-fitness in adolescent males. Twenty-eight healthy adolescent males (age, 14.9±0.74 yrs.) were randomly assigned to two groups randomly: HIIT (n=15) or control (n=13) groups. The HIIT training program was achieved three times per week over a 10-week period. Anthropometric parameters, physical performance [cardiorespiratory-fitness (maximal-oxygen-consumption), sprint-ability, squat-jump (SJ), countermovement-jump (CMJ), five-jump test (FJT)] and plasma PTH concentrations were assessed before- and after-intervention. No significant between group baseline differences were noted. Significant “time*group” interactions were found all physical fitness measures (P<0.05), but not for anthropometric parameters or PTH levels. The HIIT program resulted in an increase in maximal-oxygen-consumption (P<0.001), SJ (P=0.003), CMJ (P=0.006), FJT (P=0.001), and a decrease in 5-m (P<0.001), 10-m (P<0.001), 20-m (P=0.001) and 30-m (P=0.002) sprint times. However, no significant change was detected for PTH levels in response to 10-week intervention. Following 10-week HIIT program, physical fitness had improved, but no significant change had occurred for PTH levels in adolescent males. Further research is needed to better understand the interaction between PTH and other bone-related biochemical markers (e.g., ionized calcium, 25-hydroxyvitamin D or osteocalcin) in response to varying HIIT durations and intensities during adolescence.
Section Name Field Name Date Reason Old Value Updated Value
Eligibility Inclusion criteria 05/10/2025 There was a typo in the inclusion criteria, which I have corrected. I deleted the sentence “one football training session/week in the middle school’s sports association.” Participants in this study attended only two physical education classes per week. Thank you for your understanding. - male sex - age from 14 to 16 years - classified as normal-weight according to the World Health Organization (WHO) child growth standards for BMI (normal-weight: BMI ≤ 85th percentile) - usual physical activity consisting of weekly two-hour physical education lessons - one football training session/week in the middle school's sports association - parental approval. - male sex - age from 14 to 16 years - classified as normal-weight according to the World Health Organization (WHO) child growth standards for BMI (normal-weight: BMI ≤ 85th percentile) - usual physical activity consisting of weekly two-hour physical education lessons - parental approval.
Section Name Field Name Date Reason Old Value Updated Value
Eligibility Exclusion criteria 05/10/2025 There was a typo in the inclusion criteria, which I have corrected. I deleted the sentence “one football training session/week in the middle school’s sports association.” Participants in this study attended only two physical education classes per week. Thank you for your understanding. - consent retirement - non-compliance to the training program - participation in physical training at the time of the study or within the past 6 months (except physical education class and middle school sports association football training) - current or recent (within 3 months) dietary restriction or dietary supplementation - incomplete data - consent retirement - non-compliance to the training program - participation in physical training at the time of the study or within the past 6 months (except physical education class) - current or recent (within 3 months) dietary restriction or dietary supplementation - incomplete data
Section Name Field Name Date Reason Old Value Updated Value
Recruitment Centre RecruitmentCentre List 17/07/2025 Thank you to the Trial Reviewer for this comment. We recruited participants from only one school, and the exact name of that school has been indicated. Middle Schools, Dahmani, El Kef Governorate, Tunisia, Dahmani, 7170, Tunisia Abou Kacem Chebbi Middle School, Dahmani, El Kef Governorate, Tunisia, Dahmani, 7170, Tunisia