"We Walk": Impact of Exercise Dose on Health Outcomes Among Women Ages 60-75
| Status: | Recruiting |
|---|---|
| Healthy: | No |
| Age Range: | 60 - 75 |
| Updated: | 4/21/2016 |
| Start Date: | August 2012 |
| End Date: | August 2016 |
| Contact: | Kim Bowyer |
| Email: | CHAPMAKP@mailbox.sc.edu |
| Phone: | 803-777-8291 |
We Walk - Energy Expenditure and Health Outcomes in Older, Sedentary Women.
The overall goal is to determine whether any energy expenditure compensation in response to
16 weeks of aerobic exercise at a higher-dose is greater compared to a lower-dose
intervention in older women, and to begin to investigate underlying physiological mechanisms
that influence energy expenditure changes in older women.
16 weeks of aerobic exercise at a higher-dose is greater compared to a lower-dose
intervention in older women, and to begin to investigate underlying physiological mechanisms
that influence energy expenditure changes in older women.
The overall goal is to determine whether any energy expenditure compensation in response to
16 weeks of aerobic exercise at a higher-dose is greater compared to a lower-dose
intervention in older women, and to begin to investigate underlying physiological mechanisms
that influence energy expenditure changes in older women. Changes in all components of
energy expenditure, as well as concentrations of plasma leptin and serum free T3, in
response to the two different exercise programs (14 and 8 kcal/kg body weight weekly, 60-65%
VO2max, 4 days/wk) will be compared in older, non-obese women (60-75 yrs, BMI=18-30 kg/m2).
Specific Aim 1: To determine whether differential changes in total daily energy expenditure
and its components occur in older women in response to two exercise programs of different
doses. State-of-the-art methods will be used (total daily energy expenditure by doubly
labeled water; non-exercise activity thermogenesis using Physical Activity Monitoring
System; resting metabolic rate and thermic effect of food via indirect calorimetry).
Primary Hypothesis: Due to a greater decline in NEAT, women will exhibit a smaller increase
in total daily energy expenditure in response to the higher-dose, compared to the
lower-dose, exercise program, despite greater increases in resting metabolic rate and
thermic effect of food.
Specific Aim 2: To explore whether differential changes occur in plasma leptin and serum
free triiodo-L-thyronine (free T3) concentrations in older women in response to 16-week
aerobic exercise programs of two different doses.
We hypothesize that in response to the higher-dose exercise program, women will exhibit
larger decreases in plasma leptin and serum free T3 concentrations, compared to the
lower-dose exercise program.
We will also determine whether women exhibit greater improvements in plasma lipids, insulin
sensitivity (using homeostasis model assessment, HOMA, score), blood pressure, and aerobic
fitness in response to the higher-dose, compared to the lower-dose, exercise program.
16 weeks of aerobic exercise at a higher-dose is greater compared to a lower-dose
intervention in older women, and to begin to investigate underlying physiological mechanisms
that influence energy expenditure changes in older women. Changes in all components of
energy expenditure, as well as concentrations of plasma leptin and serum free T3, in
response to the two different exercise programs (14 and 8 kcal/kg body weight weekly, 60-65%
VO2max, 4 days/wk) will be compared in older, non-obese women (60-75 yrs, BMI=18-30 kg/m2).
Specific Aim 1: To determine whether differential changes in total daily energy expenditure
and its components occur in older women in response to two exercise programs of different
doses. State-of-the-art methods will be used (total daily energy expenditure by doubly
labeled water; non-exercise activity thermogenesis using Physical Activity Monitoring
System; resting metabolic rate and thermic effect of food via indirect calorimetry).
Primary Hypothesis: Due to a greater decline in NEAT, women will exhibit a smaller increase
in total daily energy expenditure in response to the higher-dose, compared to the
lower-dose, exercise program, despite greater increases in resting metabolic rate and
thermic effect of food.
Specific Aim 2: To explore whether differential changes occur in plasma leptin and serum
free triiodo-L-thyronine (free T3) concentrations in older women in response to 16-week
aerobic exercise programs of two different doses.
We hypothesize that in response to the higher-dose exercise program, women will exhibit
larger decreases in plasma leptin and serum free T3 concentrations, compared to the
lower-dose exercise program.
We will also determine whether women exhibit greater improvements in plasma lipids, insulin
sensitivity (using homeostasis model assessment, HOMA, score), blood pressure, and aerobic
fitness in response to the higher-dose, compared to the lower-dose, exercise program.
Inclusion Criteria:
- BMI 18-30
- Sedentary (exercising less than 20 minutes no more than 3 times per week)
- Non-smoking
- Weight stable (+/- 5%) over past 3 months
Exclusion Criteria:
- Self-reported cardiovascular disease
- Additional self-reported medical conditions
- Medications known to affect metabolism
- Excess caffeine use
- Self-reported contradictions according to ACSM
- Unwillingness to provide informed consent
We found this trial at
1
site
Columbia, South Carolina 29201
Principal Investigator: Xuewen Wang, PhD, MEd, BM
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