Physical Activity and Intermittent Exercise Training for Cardiovascular and Cognitive Gain in Obese Women

Summary

One hundred participants from a combination of (a) local advertisements and/or (b) those whose details are held on a research database (of previous volunteers indicating willingness to be contacted about future studies) will be sought to volunteer for this study. Written informed consent will be gained following greater than 48 hours for the purpose of reading the Participant Information sheets. The study will then involve two stages (i) recruiting participants for a cross sectional analysis of the relationship between physical activity levels and cardiovascular and cognitive function, and (ii) a longer exercise training study in a subsample of these volunteers (i.e. participants who volunteer to exercise train). Participants for stage 1 will then visit the laboratory in the University on three occasions (over a three week period) to be assessed for body composition, exercise tolerance, current physical activity levels, cognitive function and arterial and cardiac health. Each visit will last for 60 - 90 minutes. Participants will then be provided with an accelerometer to wear for a period of one week in order to assess movement counts and sedentary behaviour. Stage 2 will include only those participants who have volunteered for the exercise training component (approx 60). These participants will then be randomly divided into two groups. Both groups will exercise three times per week for 12 weeks duration. Group 1 will exercise in a traditional manner at a moderate intensity, whilst the second group will exercise at a heavy intensity but in short bursts. Both groups will complete the same amount of work but in two differing modes. Both groups will attend the laboratory twice per week for supervised exercise sessions and also perform one home based 30 minute brisk walk per week. All participants will be re-examined at 12 weeks.

Conditions

• Obesity
• Cognitive Ability, General
• Cardiovascular Disease

Interventions

BEHAVIORAL

Interval exercise training

Interval exercise sessions (INT) involving work:recovery ratios of 40 s at 70% delta work-rate followed by 80 s active recovery at 20 W. 70% delta (∆) is 70% of the difference between work rate peak (WRpeak) and work rate at the lactate threshold (WRLT) calculated as: 70%∆ =0.7(〖WR〗\_peak- 〖WR〗\_LT )+ 〖WR〗\_LT Where WR is work rate, LT is lactate threshold) Each session was for 30 min and this was undertaken twice per week for 12 weeks. One home based exercise session was incorporated per week.

BEHAVIORAL

Continuous exercise training (CON)

Exercise sessions involved cycling at 20%∆ work-rate peak for the duration of the session. This work-rate was chosen so that all participants in the group would be exercising in the heavy-intensity domain. To enable participants in the CON exercise group to complete the same amount of work (kJ) as the participants in the INT exercise group, the amount of work that would be completed if the CON participants completed an INT exercise session was calculated. Participants exercised for 26 min (varying to match interval group) twice per week for 12 weeks.

Sponsors & Collaborators

• University of Leeds

  lead OTHER

Principal Investigators

• Karen M Birch, PhD · University of Leeds

Study Design

Allocation

RANDOMIZED

Purpose

PREVENTION

Masking

NONE

Model

PARALLEL

Eligibility

Min Age

35 Years

Max Age

50 Years

Sex

FEMALE

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2011-06-30

Primary Completion

2014-06-30

Completion

2014-06-30

Countries

• United Kingdom

Study Locations