Health Benefits of a 6-month Brisk Walking Program in Sedentary Postmenopausal Women : a Randomized Controlled Trial

Community-dwelling women aged 55 or over are recruited at public meetings aimed at promoting physical activity in postmenopausal women.

Women are eligible and enrolled in the study if they meet the following criteria : (i) not diagnosed with any of the following conditions: rheumatoid arthritis, osteoarthritis, ischemic heart disease, previous joint replacement surgery or cerebrovascular disease affecting lower limb function, malignant tumors, (ii) without pain and medication known to alter physical performance (e.g., corticosteroids, estrogens, statins, or anti-estrogen drugs). To recruit a sample of asymptomatic sedentary postmenopausal women, women with a score value above 9.4 at the Physical Activity Questionnaire for the Elderly (PAQE) (Serres, Gautier, Varray, & Préfaut, 1998) and a 5-minute walking distance (6MWD) greater than105% of the predicted 6MWD based on Troosters' reference equation are excluded. The Troosters' reference equation is:

Before entering the study, women are asked to provide a medical certificate of no contraindication to performing the 6MWD.

Women are then randomized either to the control group (women are asked to maintain their lifestyle, and especially their physical activity habits) or to the exercise group.

The exercise intervention consists in 40 minutes of brisk walking 3d/wk for 6 months. During the 6-month program, subjects are required to attend 2 outdoor supervised sessions per week, and to exercise 1d/wk on their own, with a detailed and tailored program. The intensity of walking is adapted by skilled exercise trainers to individual physical capability of each subject. Considering that the theoretical maximum heart rate (HR) of the subject is 208-0.7 * age (Tanaka, Monahan, & Seals, 2001), the training starts at 40% of HR work (difference between maximum HR and HR at rest). Training intensity is gradually increased to finally reaching 75% of the HR work. Participants wear a heart rate monitor (Polar Elctro Inc, Woodbury, NY) during each of the 3 weekly sessions and the content of each session is collected in a notebook (meters walked, duration of the brisk walking exercise, HR, adherence to the program).