Does Participation in a Structured High-Intensity Exercise Program Influence Daily Physical Activity Patterns in Older Adults?
Washburn, Richard A., Ficker, Jennifer L., Research Quarterly for Exercise and Sport
Physical activity can play an important role in main-mining health and effective functioning in older adults (Clark, 1996; Mengelkoch et al., 1997; Pescatello & DiPietro, 1993; Phillips & Haskell, 1995; Rakowksi & Mor, 1992); however, only a small percentage of that group is physically active. For example, data from the third National Health and Nutrition Examination Survey indicated that among black, white, and Mexican American adults ages 60 years and over, approximately 26% participated in no leisure time physical activity, while the prevalence of participation in vigorous leisure time physical activity [greater than or equal to] 6 METS (metabolic rate equivalents) three or more times per week was approximately 3% (Crespo, Keteyian, Heath, & Sempos, 1996). It has been suggested that increased vigorous activity over brief periods of a day may be accompanied by decreased spontaneous activity or increased energy intake during other times of the day, thereby negating some potential benefits of participating in vigorous activity on energy balance and associated health benefits (Blair, 1997; Bouchard & Despres, 1995). The recent availability of small motions sensors that allow a detailed description of daily physical activity have made it possible to address the issue of changes in spontaneous activity that may accompany participation in vigorous, structured exercise (Tryon & Williams, 1996). This paper provides a preliminary evaluation of this question by comparing the patterns of physical activity over 2 days assessed by a portable accelerometer in a small group of older adults who were regular participants in a 3-day-per-week structured exercise program.
Eighteen healthy adult volunteers (15 women, 3 men; M age = 72.6 years, SD = 4.6, range: 67 to 80 years; M weight = 66.6 kg, SD = 14.2; M body mass index = 25.2 kg[m.sup.2], SD = 4.6) participated in this study after providing written informed consent. Participants were recruited from a university-supervised physical activity program for older adults conducted 3 days each week (Monday, Wednesday, and Friday) between 6 and 9 a.m. and consisted of warm-up stretching activities, aerobic activities (walking, jogging, aerobic dance), and resistance training. All participants first performed warm-up stretching exercises and then were free to chose the order of more vigorous activity, either aerobic or resistance training. It is estimated that participants were active for a minimum of 2 and a maximum of 3 hr during the exercise period. All participants were retired, although 10 (55.6%) engaged in volunteer work activity. Participants in this study had been attending this exercise program regularly for an average of 6.7 years (range: 9 months to 20 years).
Physical Activity Monitoring
Physical activity was assessed using a Computer Science and Applications, Inc., (CSA) (Model 7164, CSA, Shalimar, FL) portable accelerometer. The CSA accelerometer has been shown to provide valid assessments of physical activity during treadmill walking and running among college-age men and women (Freedson, Melanson, & Sirard, 1998; Melanson & Freedson, 1995), outdoor walking among middle-age adults (Washburn & Copay, 1998), and among children in both laboratory (Janz, Cassady, Barr, & Kelly, 1995; Trost et al., 1998) and dally activity (Janz, 1994; Janz, Witt, & Mahoney, 1995) settings. A complete technical description of this device+ has been published (Tryon & Williams, 1996). Briefly, the CSA accelerometer measures 5.1 x 3.8 x 1.5 cm, is lightweight (42.6 g), and powered by a readily available 2430-coin cell battery. The CSA accelerometer contains a single axis (vertical) piezoelectric bender element that generates an electrical signal proportional to the force acting on it. Acceleration detection ranges in magnitude from 0.05 to 3.2 Gs, and the frequency response ranges from 0.25 to 2. …