Physical Activity and Basal Metabolic Rate in Postmenopausal Women

Summary

The primary purpose of this study is to expand research on the effects of physical activity on basal metabolic rate (BMR) in healthy postmenopausal women, and to further compare the effects of long-term habitual exercise to the results of a shorter-term (16 weeks) training program. The investigators will measure BMR by indirect calorimetry and normalize it across subjects for body size (fat free mass) and level of aerobic fitness (VO2MAX). Two groups will be compared: an intervention group (no previous participation in regular exercise, newly enrolled in this study's 16 week training program), and a long-term athlete group (have engaged in at least 5 hours of exercise per week for the past 10 years or longer). A secondary aim is to generate an equation for the prediction of BMR from fat free mass in physically active postmenopausal women, to be applied to hypotheses in biological anthropology. The investigators expect to find at baseline that, controlling for fat free mass and VO2MAX, the long-term group will have significantly higher BMR than the intervention group. At 16 weeks the investigators expect no change in BMR for the long-term group, while BMR will have increased in the intervention group. At the same time, the investigators expect to find that after completing the training regimen, the intervention group will have BMR similar to that of the long-term athletes.

Conditions

• Postmenopausal Metabolic Health

Interventions

BEHAVIORAL

Resistance and aerobic exercise

Following baseline measurements, sedentary women were enrolled in a 16-week exercise training program at the YMCA in La Jolla, CA. Exercise occurred 3 times per week, for 1.5 hours each time. Exercise consisted of stretching, 20 minutes of aerobic exercise on elliptical machines, and 3 sets of 10-12 repetitions to failure for each of ten weight lifting exercises: abdominal crunch, arm curl, arm extension, chest press, lat pull-down, leg curl, leg extension, leg press, seated row, and trunk extension. Women started at 65-75% of 1-repetition-maximum, and resistance was increased as necessary to maintain the number of sets and reps and to continue to work to failure. Exercise was monitored by a TechnoGym electronic key system, and trainers instructed and supervised subjects in the gym.

Sponsors & Collaborators

• Wenner Gren

  collaborator UNKNOWN

• Sigma Xi

  collaborator UNKNOWN

• National Center for Research Resources (NCRR)

  collaborator NIH

• University of California, San Diego

  lead OTHER

Principal Investigators

• Andrew W Froehle, PhD · University of California, San Diego

Study Design

Allocation

NON_RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

NONE

Model

PARALLEL

Eligibility

Min Age

40 Years

Max Age

120 Years

Sex

FEMALE

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2008-01-31

Primary Completion

2010-08-31

Completion

2010-08-31

Countries

• United States

Study Locations