CrossFit Exercise to Improve Glucose Control for Overweight and Obese Adults

Kansas State University

Status: Completed

Conditions: Hyperglycemia

Treatments: Other: High-Intensity Functional Training; Other: Aerobic and Resistance Training

Study type: Interventional

Funder types: Other

Identifiers

NCT02185872

#6058

Details and patient eligibility

About

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.

Full 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.

Enrollment: 23 patients

Sex: All

Ages: 18 to 40 years old

Volunteers: Accepts Healthy Volunteers

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

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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23 participants in 2 patient groups

Aerobic and Resistance Training

Active Comparator group

Description:

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.

Treatment:

Other: Aerobic and Resistance Training

High-intensity functional training

Experimental group

Description:

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.

Treatment:

Other: High-Intensity Functional Training