CrossFit Exercise to Improve Glucose Control for Overweight and Obese Adults

March 30, 2015 updated by: Katie M. Heinrich, Kansas State University

The Influence of a CrossFit Exercise Program on Glucose Control in Overweight and Obese Individuals

The purpose of this study was to examine the differences in glucose control, fitness, and body composition between a standard aerobic and resistance exercise training program and a shorter-duration, high-intensity CrossFit training program in overweight and obese physically inactive adults.

Hypotheses:

  1. Both groups would improve glucose control, with the CrossFit group improving significantly more than the aerobic and resistance training group.
  2. Both groups would improve fitness, with the CrossFit group improving significantly more than the aerobic and resistance training group.
  3. Both groups would demonstrate decreases in body fat percentage and fat mass and increases in lean body mass, with the CrossFit group improving significantly more than the aerobic and resistance training group.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Overweight or obese participants will take part in an 8-week exercise intervention after clearance from a doctor, that is expected to improve glucose control, fitness (Eurofit and peak aerobic capacity), and body composition (body fat percentage, fat mass, and lean body mass). After stratification by age and body mass index, participants will be randomized to either a standard aerobic and resistance training exercise program or a relatively higher intensity, shorter duration CrossFit exercise program.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
23

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Kansas
      • Manhattan, Kansas, United States, 66506
        • Kansas State University

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years to 40 years (Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • body mass index (BMI) of 25 - < 40, physically inactive (i.e., not participating in any structured exercise programs for the past 2 months and not exceeding 30 total minutes of physical activity per week)

Exclusion Criteria:

  • current smoker, pregnant, taking blood glucose altering medications, heart disease, type 1 or 2 diabetes mellitus, total cholesterol 200 mg/dL or higher

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

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

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Active Comparator: Aerobic and Resistance Training
Participants completed 24 exercise sessions based on current guidelines. Aerobic exercise (50 min) was performed on machines every session and resistance training (20 min) was performed on machines two sessions per week. Aerobic intensity was prescribed at 40-50% of heart rate reserve (HRR) Weeks 1-4 and 50-60% HRR Weeks 5-8. Resistance training was supervised by an ACE certified personal trainer. One-repetition maximums (1-RM) were assessed Week 1 (i.e., seated bicep curl, military press, seated lat pulldown, seated leg extension, triceps pulldown, bench press, reverse leg curl, seated leg press). For Weeks 2-3 participants completed, 3 sets of 15 reps at 50% 1-RM; Weeks 4-5, 3 sets of 12 reps at 60% 1-RM; Weeks 6-7, 3 sets of 10 reps at 70% 1-RM; Week 8, 3 sets of 8 reps at 75% 1-RM. Three sets of 15 unweighted crunches were completed each day. One minute of rest was taken between each set and each exercise.
Other: Aerobic and Resistance Training
The protocol was based upon current guidelines of 150 minutes moderate-intensity aerobic activity and 2 days of muscle strengthening per week.
Experimental: High-intensity functional training
Participants completed a total of 24 sessions that were pre-programmed and led by a certified instructor (CrossFit Level 2), which lasted up to 60 minutes in duration. The first two class periods were structured as an introduction to common movements used in high-intensity functional training (HIFT; e.g., squats, deadlift, press, jerks, barbell, dumbbell, and medicine ball cleans, pullups, kettlebell swings, among others). No scheduled workouts were given on days 1 and 2. Beginning on day 3 each HIFT class consisted of 10-15 minutes of stretching and warmup, 10-20 minutes of instruction and practicing techniques and movements, and 5-30 minutes for the workout of the day, performed at vigorous intensity, relative to each person's ability and fitness level. All weights and movements were individually prescribed and recorded for each participant.
Other: High-Intensity Functional Training
Participants were instructed to work as hard as they could while maintaining safe technique and proper form to achieve as many reps or rounds as possible in the prescribed time frame. As HIFT participants became accustomed to specific movements, less time was dedicated to practicing movements and technique.
Other Names:
  • CrossFit

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Change from baseline in glucose control.
Time Frame: Baseline, Week 10
Fasting plasma glucose levels were taken after an overnight fast of at least 8 hours. An oral glucose tolerance test was conducted after ingestion of a 75g oral dextrose solution with finger sticks at 30, 45, and 60 minutes from time 0. The following equation was used to calculate glucose area under the curve which was the metric utilized to ascertain changes in glucose control: [(Time 45 - Time 30) * ½ (OGTT 30 + OGTT 45)] + [(Time 60 - Time 45) * ½ (OGTT 60 + OGTT 45)]
Baseline, Week 10

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Change from baseline in peak aerobic capacity
Time Frame: Baseline, Week 10
Modified Balke protocol
Baseline, Week 10
Change from baseline in sit and reach
Time Frame: Baseline, Week 10
Eurofit protocol for sit and reach distance using flex tester box
Baseline, Week 10
Change from baseline in standing broad jump
Time Frame: Baseline, Week 10
Eurofit protocol
Baseline, Week 10
Change from baseline in vertical jump
Time Frame: Baseline, Week 10
Eurofit protocol
Baseline, Week 10
Change from baseline in pushups
Time Frame: Baseline, Week 10
Eurofit protocol; completed on feet or knees
Baseline, Week 10
Change from baseline in situps
Time Frame: Baseline, Week 10
Eurofit protocol
Baseline, Week 10
Change from baseline in 40 meter dash
Time Frame: Baseline, Week 10
A handheld stopwatch was used to record time from the command "Go" until the participant crossed the line at 40 meters
Baseline, Week 10
Change from baseline in stork balance test
Time Frame: Baseline, Week 10
Baseline, Week 10
Change from baseline in body composition
Time Frame: Baseline, Week 12
Dual X-ray absorptiometry scan was used to assess body fat percentage, lean body mass, and fat mass.
Baseline, Week 12

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Time spent completing daily workouts
Time Frame: 24 exercise sessions over 8 weeks
Time spent to complete each assigned daily workout was individually recorded for each participant
24 exercise sessions over 8 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Kansas State University

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Katie M Heinrich, PhD, Kansas State University
  • Study Director: Pratik Patel, MS, RD, Kansas State University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
February 1, 2012

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
May 1, 2012

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
May 1, 2012

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
July 3, 2014

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 9, 2014

First Posted (Estimate)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
July 10, 2014

Study Record Updates

Last Update Posted (Estimate)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
March 31, 2015

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 30, 2015

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
March 1, 2015

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • #6058

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