Cardiovascular Risk in Sedentary Elderly During Prolonged Sitting Time Versus Intermittent Sitting Time

Summary

In adults, the sedentary behavior was related to cardiovascular risk markers, regardless of the level of physical activity (PA). However, the interruption of prolonged sedentary time has shown positive results even when performed in breaks of low intensity and short duration of activity. The aim of this study is to analyze the influence of a sedentary uninterrupted period, as well as different forms of breaks in sedentary time for the glycemic, insulin and inflammatory markers responses in older adults. This is a controlled clinical trial to be conducted in older (≥ 65 years) and sedentary (\<150 min / week of moderate to vigorous physical activity) people. Those with BMI ≥ to 35.00 kg /m2; diabetic, on medication for glycemic control, or with absolute or relative contraindications to PA practice will not be included . Participants will undergo four phases of intervention separated by an interval of 7 days: (1) Prolonged Sitting Time(PST), in which older people will stay for 5 hours seated; (2) Prolonged sitting with PA of light intensity and short duration (LiSd), time sitting is interrupted for PA bouts of 50-60% of the Heart Rate (HR)max; (3) Prolonged sitting with PA of moderate intensity and short duration (MiSd), time sitting will be interrupted for PA bouts of 65-75% predicted HR max; (4) Prolonged sitting with PA of moderate intensity and long duration (MiLd,) time sitting will be interrupted with PA bouts of 65-75% of HRmax. PA bouts will be performed by walking into a hallway every 20 minutes of sitting time and will last 2 minutes, except in MiLd phase (10 minute breaks every 75 minutes). To evaluate the effects of different PA interruptions in plasma glucose, serum insulin and inflammatory markers, blood samples will be collected serially (-30min, Baseline and 30min, 1h, 2h, 3h, 4h and 5h after a standardized meal. It is expect that interruption of sedentary time, even with breaks of short duration and light intensity can bring benefits to cardiovascular risk markers even in the elderly.

Conditions

• Sedentary Lifestyle

Interventions

OTHER

Prolonged sitting time

Volunteers will be continuously sitting on a chair for 5 hours and should move the least possible. If the participant needs to stand from the chair, the stage will be invalidated.

OTHER

PST+Light intensity Short bouts PA

Volunteers will have their time sitting interrupted every 20 minutes for 2 minutes of physical activity of low intensity. In the active period, participants will be encouraged to walk in the hallway and reach a training heart rate between 50-60% HR max predicted for the age and measured by heart rate monitor. The Borg scale will be used at the beginning and the end of each active period in order to measure the subjective effort of the participants. In the end the volunteers will be sitting 5 hours and have 30 minutes (15 bouts of 2 minutes) of light intensity physical activity.

OTHER

PST+Moderate intensity Short bouts PA

Volunteers will have their time sitting interrupted every 20 minutes for 2 minutes of physical activity of moderate intensity. In the active period, participants will be encouraged to walk in the hallway and reach a training heart rate between 65 a 75% HR max predicted for the age and measured by heart rate monitor. The Borg scale will be used at the beginning and the end of each active period in order to measure the subjective effort of the participants. In the end the volunteers will be sitting 5 hours and have 30 minutes (15 bouts of 2 minutes)of moderate intensity physical activity.

OTHER

PST+Moderate intensity Long bouts PA

Volunteers will have their time sitting interrupted every 75 minutes for 10 minutes of physical activity of moderate intensity. In the active period, participants will be encouraged to walk in the hallway and reach a training heart rate between 65 a 75% HR max predicted for the age and measured by heart rate monitor. The Borg scale will be used at the beginning and the end of each active period in order to measure the subjective effort of the participants. In the end the volunteers will be sitting 5 hours and have 30 minutes (3 bouts of 10 minutes) of moderate intensity physical activity.

Sponsors & Collaborators

• University of Sao Paulo

  lead OTHER

Principal Investigators

• Eduardo Ferriolli, PhD · USao Paulo

Study Design

Allocation

RANDOMIZED

Masking

NONE

Model

PARALLEL

Eligibility

Min Age

65 Years

Sex

FEMALE

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2015-08-31

Primary Completion

2016-12-31

Completion

2016-12-31

Countries

• Brazil

Study Locations