HealthyCr + HIITNCT02370212
Interval Training Plus Creatine Effects on Performance and Glucose Tolerance
A study testing Creatine and High intensity interval training in people with Healthy, run by University of British Columbia.
Trial summary
Recent evidence suggests that high -intensity interval training (HIIT) may be an effective strategy to improve cardiorespiratory fitness, exercise performance, and insulin sensitivity. In addition, creatine (Cr), a nitrogen- containing compound, is widely used to enhance high intensity exercise performance. Read more about this study
- Who is it for?
- Ages 18 to 35 yearsHealthy volunteers can take part
- Conditions the study is for
- Healthy
- What is being tested?
- Creatine and High intensity interval training
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 18 participants
- Where
- No sites listed yet
- Study dates
- Mar 2015to Apr 2015
- Phase
- Interventional
- Are there results?
- None posted in the registry
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 35 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Between 18--35 years of age
- Can read, comprehend, and speak English
- Free of diagnosed metabolic disease (e.g., prediabetes, diabetes)
- Willing and able to perform high-intensity exercise training
- Willing and able to consume creatine or placebo supplements over the study period
Who cannot join
- Diagnosed metabolic disorder such as diabetes, metabolic syndrome, prediabetes, hypothyroidism, cardiovascular disease or any other condition known to affect metabolism
- Currently engaged in high-intensity interval training >2 time per week
- Currently taking creatine or other supplements or having taken creatine in the last 12 weeks
About this study
Recent evidence suggests that high -intensity interval training (HIIT) may be an effective strategy to improve cardiorespiratory fitness, exercise performance, and insulin sensitivity. In addition, creatine (Cr), a nitrogen- containing compound, is widely used to enhance high intensity exercise performance. A seminal study demonstrated that the muscle content of Cr and phosphocreatine (PCr) can be elevated by exogenous Cr. Oral intake of Cr increases the concentration in blood and muscle, and part of the increased muscle Cr is transformed to PCr (a process catalyzed by Cr kinase). Cr supplementation increases total Cr (TCr = Cr + PCr) by ~20%, with the PCr component accounting for 10% of the increase.
Combining HIIT and Cr is intriguing for two reasons; first, Cr supplementation improves performance through increasing PCr, PCr recovery, and muscle buffering which may facilitate higher training intensities and therefore greater training adaptations. Secondly, both Cr and HIIT have individually been shown to increase GLUT 4 and insulin sensitivity, suggesting that Cr supplementation may be an adjunct to HIIT for improving glucose control. To date, there have only been two studies investigating the performance effects of Cr combined with HIIT with preliminary positive results. No studies have examined the impact of combined Cr + HIIT on outcomes related to insulin sensitivity. Therefore, the purpose of this research is to examine the combined effects of Cr and HIIT on performance and insulin sensitivity as determined via an oral glucose tolerance test (OGTT) in young healthy adults.
Read the detailed description
PURPOSE: To determine whether combining creatine with high intensity interval training (HIIT) results in better exercise performance and insulin sensitivity when compared to HIIT combined with placebo in healthy subjects.
HYPOTHESES: a) Creatine + HIIT will result in improved exercise performance compared to placebo; b) Creatine + HIIT will result in improved insulin sensitivity compared to placebo.
OBJECTIVES: To determine whether combining creatine with high intensity interval training (HIIT) results in better exercise performance and insulin sensitivity when compared to HIIT combined with placebo in healthy subjects.
RESEARCH METHOD: A double blind placebo randomized controlled trial (RCT) in which 24 healthy young volunteers will participate in HIIT three times a week, for four weeks. Participants will be will be stratified for sex and randomized to one of two interventions; 1) HIIT plus Cr, or 2) HIIT plus placebo.
STATISTICAL ANALYSES: A 2 (group) x 2 (time) way repeated measures ANOVA will be used to analyze all variables. Descriptive statistics (means, standard deviations [SD], and frequencies) will be calculated. Histograms will be used to identify any outliers and to test for normality. Data with skewed distributions will be log-transformed prior to statistical testing. Within group differences will be examined by paired t-test.
24 participants will be included in this RCT. Sample size calculations were computed using means and standard deviations from a previous Cr + HIIT study [11] which showed an significant increase in cycling critical power with Cr + HIIT (6.72 +/- 2.54 % increase) compared to Placebo + HIIT (3.82 +/- 2.30 %). With 80% power at an alpha of 0.05 indicated that 11 participants per group are needed. To preserve power and account for potential drop-out we will recruit 12 per group.
- Conditions
- Healthy
- Being tested
- Creatine, Placebo, High intensity interval training
- Keywords
- Creatine, interval training, effects on performance
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
CreatineDietary supplement
PlaceboDietary supplement
High intensity interval trainingOther
| Study group | Role | What they receive |
|---|---|---|
| Creatine | Experimental | Creatine will be ingested after interval training and at supper time on training days and in the morning and afternoon on non-training days (0.05 g/kg body mass of creatine with 0.05 g/kg flavoured dextrose per dose).
Both experimental and placebo groups will perform the same high intensity interval training protocols (3x/week for 4 weeks). Receives: Dietary Supplement: Creatine; Other: High intensity interval training |
| Placebo | Placebo comparator | The placebo will be ingested after interval training and at supper time on training days and in the morning and afternoon on non-training days (0.1 g/kg flavoured dextrose per dose, isocaloric to the creatine).
Both experimental and placebo groups will perform the same high intensity interval training protocols (3x/week for 4 weeks). Receives: Dietary Supplement: Placebo; Other: High intensity interval training |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change from Baseline in exercise performance at 4 weeks
Assessed by a 50 kilojoule (kJ) time trial test
Measured: 4 weeks
Secondary outcomes (3)
Change from Baseline in cardiorespiratory fitness
Measured by a VO2peak test
Measured: 4 weeks
Change from Baseline in body composition
Measured by a DXA scan
Measured: 4 weeks
Change from Baseline in insulin sensitivity
Assessed using an oral glucose tolerance test (OGTT)
Measured: 4 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Feb 2015 (estimated)
- Study startMar 2015
- Primary completionApr 2015
- Study completionApr 2015
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for HealthyStudies of the same condition, open and under way.
- More trials run by University of British ColumbiaThe sponsor's other registered studies.
- 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
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 18 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of British Columbia
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02370212
- Sponsor's protocol ID
- H15--00205
- Acronym
- Cr + HIIT
- Status last verified
- Jan 2016
- First submitted
- 4 Feb 2015
- Last updated
- 20 Jan 2016
- Results posted
- No
Study at a glance
From the registry record, last updated by the sponsor on 20 Jan 2016. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Interval Training Plus Creatine Effects on Performance and Glucose Tolerance
- ClinicalTrials.gov ID
- NCT02370212
- Acronym / sponsor ID
- Cr + HIIT / H15--00205
- Conditions
- Healthy
- Keywords
- Creatine, interval training, effects on performance
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 18 participants (actual)
- Lead sponsor
- University of British ColumbiaUniversity, hospital or other
- Study start
- Mar 2015
- Primary completion
- Apr 2015 (actual)
- Study completion
- Apr 2015 (actual)
- First posted
- 24 Feb 2015 (estimated)
- 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.
Recent evidence suggests that high -intensity interval training (HIIT) may be an effective strategy to improve cardiorespiratory fitness, exercise performance, and insulin sensitivity. In addition, creatine (Cr), a nitrogen- containing compound, is widely used to enhance high intensity exercise performance. A seminal study demonstrated that the muscle content of Cr and phosphocreatine (PCr) can be elevated by exogenous Cr. Oral intake of Cr increases the concentration in blood and muscle, and part of the increased muscle Cr is transformed to PCr (a process catalyzed by Cr kinase). Cr supplementation increases total Cr (TCr = Cr + PCr) by ~20%, with the PCr component accounting for 10% of the increase.
Combining HIIT and Cr is intriguing for two reasons; first, Cr supplementation improves performance through increasing PCr, PCr recovery, and muscle buffering which may facilitate higher training intensities and therefore greater training adaptations. Secondly, both Cr and HIIT have individually been shown to increase GLUT 4 and insulin sensitivity, suggesting that Cr supplementation may be an adjunct to HIIT for improving glucose control. To date, there have only been two studies investigating the performance effects of Cr combined with HIIT with preliminary positive results. No studies have examined the impact of combined Cr + HIIT on outcomes related to insulin sensitivity. Therefore, the purpose of this research is to examine the combined effects of Cr and HIIT on performance and insulin sensitivity as determined via an oral glucose tolerance test (OGTT) in young healthy adults.
Detailed description
PURPOSE: To determine whether combining creatine with high intensity interval training (HIIT) results in better exercise performance and insulin sensitivity when compared to HIIT combined with placebo in healthy subjects.
HYPOTHESES: a) Creatine + HIIT will result in improved exercise performance compared to placebo; b) Creatine + HIIT will result in improved insulin sensitivity compared to placebo.
OBJECTIVES: To determine whether combining creatine with high intensity interval training (HIIT) results in better exercise performance and insulin sensitivity when compared to HIIT combined with placebo in healthy subjects.
RESEARCH METHOD: A double blind placebo randomized controlled trial (RCT) in which 24 healthy young volunteers will participate in HIIT three times a week, for four weeks. Participants will be will be stratified for sex and randomized to one of two interventions; 1) HIIT plus Cr, or 2) HIIT plus placebo.
STATISTICAL ANALYSES: A 2 (group) x 2 (time) way repeated measures ANOVA will be used to analyze all variables. Descriptive statistics (means, standard deviations [SD], and frequencies) will be calculated. Histograms will be used to identify any outliers and to test for normality. Data with skewed distributions will be log-transformed prior to statistical testing. Within group differences will be examined by paired t-test.
24 participants will be included in this RCT. Sample size calculations were computed using means and standard deviations from a previous Cr + HIIT study [11] which showed an significant increase in cycling critical power with Cr + HIIT (6.72 +/- 2.54 % increase) compared to Placebo + HIIT (3.82 +/- 2.30 %). With 80% power at an alpha of 0.05 indicated that 11 participants per group are needed. To preserve power and account for potential drop-out we will recruit 12 per group.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, investigator)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Creatine | Experimental | Dietary Supplement: Creatine, Other: High intensity interval trainingCreatine will be ingested after interval training and at supper time on training days and in the morning and afternoon on non-training days (0.05 g/kg body mass of creatine with 0.05 g/kg flavoured dextrose per dose). Both experimental and placebo groups will perform the same high intensity interval training protocols (3x/week for 4 weeks). |
| Placebo | Placebo comparator | Dietary Supplement: Placebo, Other: High intensity interval trainingThe placebo will be ingested after interval training and at supper time on training days and in the morning and afternoon on non-training days (0.1 g/kg flavoured dextrose per dose, isocaloric to the creatine). Both experimental and placebo groups will perform the same high intensity interval training protocols (3x/week for 4 weeks). |
Who may qualify
- Ages
- 18 to 35 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (5 listed)
- Between 18--35 years of age
- Can read, comprehend, and speak English
- Free of diagnosed metabolic disease (e.g., prediabetes, diabetes)
- Willing and able to perform high-intensity exercise training
- Willing and able to consume creatine or placebo supplements over the study period
Key exclusion criteria (3 listed)
- Diagnosed metabolic disorder such as diabetes, metabolic syndrome, prediabetes, hypothyroidism, cardiovascular disease or any other condition known to affect metabolism
- Currently engaged in high-intensity interval training >2 time per week
- Currently taking creatine or other supplements or having taken creatine in the last 12 weeks
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 |
|---|---|---|
| Creatine | Dietary supplement | Creatine |
| Placebo | Dietary supplement | Placebo |
| High intensity interval training | Other | Creatine, Placebo |
Primary outcome
Change from Baseline in exercise performance at 4 weeks
Time frame: 4 weeks
Assessed by a 50 kilojoule (kJ) time trial test
3 secondary outcomes
Change from Baseline in cardiorespiratory fitness
Time frame: 4 weeks
Change from Baseline in body composition
Time frame: 4 weeks
Change from Baseline in insulin sensitivity
Time frame: 4 weeks
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 20 Jan 2016.
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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. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
Questions about this trial
What is this clinical trial studying?
A study testing Creatine and High intensity interval training in people with Healthy, run by University of British Columbia.
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 5 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: finished, as of the sponsor's last update on 20 Jan 2016. Status can change between updates, so confirm with the study contact before making plans.
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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change from Baseline in exercise performance at 4 weeks (time frame: 4 weeks). 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 20 Jan 2016; AzTrials last refreshed its copy on 31 Oct 2026.