The 6-min walk test (6MWT) is a common component of fitness assessments of older adults; however, differing course configurations might affect 6MWT performance. It is unclear how comparable 2 different configurations are. To determine the comparability of 2 courses, 35 adults ≥65 years of age completed two 6MWT, once walking around a 20- by 5-yd outdoor rectangle and once on an indoor oval track (circumference 144.3 yd). Scores for the 2 tests were internally consistent (intraclass correlation coefficient = .95). The participants walked farther on the oval track than around the rectangle (639 ± 19 vs. 582 ± 16 yd; p < .0001), but responses to the rectangular configuration could be readily estimated using the equation 66.7 yd + 0.807 × (oval walking distance), R 2 = .85. Thus, within-participant responses are similar across both 6MWT, but the course configuration affects the distance walked.
Del N. Konopka, Robin P. Shook, Marian L. Kohut, Rosalie Vos Tulp, and Warren D. Franke
Edward Archer, Amanda E. Paluch, Robin P. Shook, and Steven N. Blair
Successful aging encompasses more than just the prevention of disease and disability; the truly well-lived life is demonstrated by a sense of vitality and independence, freedom from bodily pain, and the continued involvement in meaningful activities. While physical inactivity and sedentary behaviors accelerate the aging process, deliberate exercise and other forms of activity delay and/or prevent the onset of age-related pathologies such as frailty, osteoporosis, sarcopenia, and cardiovascular disease. This review surveys the evidence that supports the position that physical activity is a necessary component for the development and maintenance of the physiological resources that are foundational to physical and cognitive functioning and ‘living well’ in one's later years.
Greg Welk, Youngwon Kim, Robin P. Shook, Laura Ellingson, and Roberto L. Lobelo
The study evaluated the concurrent and criterion validity of a new, disposable activity monitor designed to provide objective data on physical activity and energy expenditure in clinical populations.
A sample of healthy adults (n = 52) wore the disposable Metria IH1 along with the established Sensewear armband (SWA) monitor for a 1-week period. Concurrent validity was examined by evaluating the statistical equivalence of estimates from the Metria and the SWA. Criterion validity was examined by comparing the relative accuracy of the Metria IH1 and the SWA for assessing walking/running. The absolute validity of the 2 monitors was compared by computing correlations and mean absolute percent error (MAPE) relative to criterion data from a portable metabolic analyzer.
The output from 2 monitors was highly correlated (correlations > 0.90) and the summary measures yielded nearly identical allocations of time spent in physical activity and energy expenditure. The monitors yielded statistically equivalent estimates and had similar absolute validity relative to the criterion measure (12% to 15% error).
The disposable nature of the adhesive Metria IH1 monitor offers promise for clinical evaluation of physical activity behavior in patients. Additional research is needed to test utility for counseling and behavior applications.
Amanda E. Paluch, Robin P. Shook, Gregory A. Hand, Daniel P. O’Connor, Sara Wilcox, Clemens Drenowatz, Meghan Baruth, Stephanie Burgess, and Steven N. Blair
Background: This study examined how life event occurrences and stressfulness influence objectively measured light through vigorous physical activity (PA) among young adults. Methods: Every 3 months over a 12-month period, 404 healthy young adults completed questionnaires on the occurrence and stress of 16 life events and wore an accelerometer for 10 days. Results: A modest positive relationship was seen between cumulative life event occurrences [between effect: β = 22.2 (9.7) min/d, P = .02] and cumulative stress [between effect: β = 7.6 (2.9) min/d, P = .01] with light through vigorous PA among men. When considering events individually, job change, starting a first job, beginning a mortgage, and changes in a relationship influenced men’s PA. For women, mortgage, starting a first job, job change, and engagement had significant associations. Life event stressfulness influenced PA in women more than in men. For men, stress from changes in a relationship or job positively influenced PA. Stress of a mortgage, quitting a job, changing jobs or a first job influenced women’s PA. Conclusion: Considering each life event individually was more informative than the summation of life events or summation of stress. Specific life events substantially altered PA, and this change varied by gender, direction of association, and PA intensity and duration.
Gregory A. Hand, Robin P. Shook, Daniel P. O’Connor, Madison M. Kindred, Sarah Schumacher, Clemens Drenowatz, Amanda E. Paluch, Stephanie Burgess, John E. Blundell, and Steven N. Blair
Background: The present study examined, among weight-stable overweight or obese adults, the effect of increasing doses of exercise energy expenditure (EEex) on changes in total daily energy expenditure (TDEE), total body energy stores, and body composition. Methods: Healthy, sedentary overweight/obese young adults were randomized to one of 3 groups for a period of 26 weeks: moderate-exercise (EEex goal of 17.5 kcal/kg/wk), high-exercise (EEex goal of 35 kcal/kg/wk), or observation group. Individuals maintained body weight within 3% of baseline. Pre/postphysical activity between-group measurements included body composition, calculated energy intake, TDEE, energy stores, and resting metabolic rate. Results: Sixty weight-stable individuals completed the protocols. Exercise groups increased EEex in a stepwise manner compared with the observation group (P < .001). There was no group effect on changes in TDEE, energy intake, fat-free mass, or resting metabolic rate. Fat mass and energy stores decreased among the females in the high-exercise group (P = .007). Conclusions: The increase in EEex did not result in an equivalent increase in TDEE. There was a sex difference in the relationship among energy balance components. These results suggest a weight-independent compensatory response to exercise training with potentially a sex-specific adjustment in body composition.
Robin P. Shook, Nicole C. Gribben, Gregory A. Hand, Amanda E. Paluch, Gregory J. Welk, John M. Jakicic, Brent Hutto, Stephanie Burgess, and Steven N. Blair
Subjective measures of moderate and vigorous physical activity (MVPA) rely on relative intensity whereas objective measures capture absolute intensity; thus, fit individuals and unfit individuals may perceive the same activity differently.
Adults (N = 211) wore the SenseWear Armband (SWA) for 10 consecutive days to objectively assess sedentary time and MVPA. On day 8, participants completed the International Physical Activity Questionnaire (IPAQ) to subjectively assess sitting time and MVPA. Fitness was assessed via a maximal treadmill test, and participants were classified as unfit if the result was in the bottom tertile of the study population by sex or fit if in the upper 2 tertiles.
Overall, estimates of MVPA between the IPAQ and SWA were not significantly different (IPAQ minus SWA, 67.4 ± 919.1 MVPA min/wk, P = .29). However, unfit participants overestimated MVPA using the IPAQ by 37.3% (P = .02), but fit participants did not (P = .99). This between-group difference was due to overestimation, using the IPAQ, of moderate activity by 93.8 min/wk among the unfit individuals, but underestimation of moderate activity among the fit participants by 149.4 min/wk.
Subjective measures of MVPA using the IPAQ varied by fitness category; unfit participants overestimated their MVPA and fit participants accurately estimated their MVPA.