Effects of Exercise Training Amount and Intensity on Cardiovascular Disease Risk Factors in Middle-Age Men and Women at Risk for Cardiovascular Disease

Status

Not yet recruiting

Phases

Unknown

Study type

Interventional

Source

ANZCTR

Registry ID

ACTRN12613000583741

Enrollment

Registered

2013-05-24

Start date

2013-06-05

Completion date

Unknown

Last updated

2020-01-13

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

None listed

Brief summary

The proposed trial is a randomised controlled clinical trial designed to study the effects of exercise training programmes differing in exercise volume (kcal/kg/wk) and/or exercise intensity (relative to maximal oxygen uptake reserve – VO2R) on cardiovascular disease risk factors in a cohort with existing risk factors for CVD. It has been recommended that additional studies be undertaken to assess the doses (volume and exercise intensity) of exercise required to elicit beneficial effects on established CVD risk factors and overall cardiovascular health. Identification of the specific amount and intensity of exercise for achieving specific outcomes will advance exercise prescription guidelines for future primary prevention programmes. Understanding these dose response relationships will ultimately result in enhanced evidence-based practice. Aims and hypotheses: 1. To determine if there will be greater CVD risk factor reduction following participation in a moderate-intensity (50% VO2R), high-volume (16 kcal/kg/wk) exercise programme compared to a moderate-intensity (50% VO2R), low-volume (8 kcal/kg/wk) exercise programme. It is hypothesized that in a dose-response manner, there will be greater CVD risk factor improvements in the moderate-intensity, high-volume exercise group. 2. To determine if there will be greater CVD risk factor reduction following participation in a vigorous-intensity (80% VO2R), high-volume (16 kcal/kg/wk) exercise programme compared to a moderate-intensity (50% VO2R), high-volume (16 kcal/kg/wk) exercise programme. It is hypothesized that in a dose-response manner, there will be greater CVD risk factor improvements in the vigorous-intensity, high-volume exercise group.

Interventions

Randomised controlled trial - 12 weeks Arm 1: moderate-intensity (50% VO2R), high-volume (16 kcal/kg/wk) aerobic (treadmill and cycle ergometer) exercise programme. Arm 2: moderate-intensity (50% VO2R), low-volume (8 kcal/kg/wk) aerobic (treadmill and cycle ergometer) exercise programme. Arm 3: vigorous-intensity (80% VO2R), high-volume (16 kcal/kg/wk) aerobic (treadmill and cycle ergometer) exercise programme. Notes: 1. Frequency and duration of individual exercise sessions will vary across participants in order to meet specific arm exposures for exercise intensity (i.e., %VO2R) and exercise volume (i.e., kcal/kg/wk). 2. All individual exercise sessions will be supervised by an exercise physiologist. 3. Attendance records and participant logs will be used to monitor exercise programme adherence.

Study design

Allocation

Randomised controlled trial

Primary purpose

Treatment

Eligibility

Sex/Gender

All

Age

18 Years to 50 Years

Healthy volunteers

Inclusion criteria

Overweight or obese (body mass index – BMI between 25-40 kg/m2); resting systolic blood pressure (SBP) of 110-159 mmHg and a resting diastolic blood pressure (DBP) less than or equal to 99 mmHg; clinically stable and have no known metabolic diseases; not performing regular physical activity – defined as completing no more than 20 minutes of structured exercise, 2 days/wk, at any time during the previous 6 months.

Exclusion criteria

Participants will be excluded if they are already physically active; have terminal illness; a psychiatric disorder, have significant exercise limitations; or evidence of CVD.

Outcome results