The purpose of this study was to assess the reliability and validity of a 6-min walk test as a measure of physical endurance in older adults. Seventy-seven subjects, ages 60-87. performed three separate 6-min walk tests and a treadmill test and completed questionnaire items assessing physical activity level and functional status. The 6-min walk had good test-retest reliability (.88 <R < .94). particularly when a practice trial preceded the test trial. Convergent validity of the 6-min walk was demonstrated by its moderate correlation (.71 < r < .82) with treadmill performance. Construct validity was assessed by determining the ability of the test to detect differences between different age and activity level groups. As expected, walking scores decreased significantly across decades and were significantly lower for low-active subjects compared to high-active subjects. There was a moderate relationship between 6-min walk scores and self-reported functional ability. It was concluded that the 6-min walk can be used to obtain reasonably reliable and valid measures of physical endurance in older adults and that it moderately reflects overall physical functional performance.
Roberta E. Rikli and C. Jessie Jones
Leslie Peacock, Allan Hewitt, David A. Rowe and Rona Sutherland
The study investigated (a) walking intensity (stride rate and energy expenditure) under three speed instructions; (b) associations between stride rate, age, height, and walking intensity; and (c) synchronization between stride rate and music tempo during overground walking in a population of healthy older adults.
Twenty-nine participants completed 3 treadmill-walking trials and 3 overground-walking trials at 3 self-selected speeds. Treadmill VO2 was measured using indirect calorimetry. Stride rate and music tempo were recorded during overground-walking trials.
Mean stride rate exceeded minimum thresholds for moderate to vigorous physical activity (MVPA) under slow (111.41 ± 11.93), medium (118.17 ± 11.43), and fast (123.79 ± 11.61) instructions. A multilevel model showed that stride rate, age, and height have a significant effect (p < .01) on walking intensity.
Healthy older adults achieve MVPA with stride rates that fall below published minima for MVPA. Stride rate, age, and height are significant predictors of energy expenditure in this population. Music can be a useful way to guide walking cadence.
Karsten Koehler, Thomas Abel, Birgit Wallmann-Sperlich, Annika Dreuscher and Volker Anneken
Inactivity and overweight are major health concerns in children and adolescents with disabilities. Methods for the assessment of activity and energy expenditure may be affected negatively by the underlying disability, especially when motor function is impaired. The purpose of this study was to assess the validity of the SenseWear Armband in adolescents with cerebral palsy and hemiparesis.
Ten volunteers (age: 13.4 ± 1.6 years) were equipped with SenseWear Armbands on the hemiparetic and nonhemiparetic side of the body. Energy expenditure was measured at rest and during treadmill exercise (speed range: 0.85 to 2.35 m/s). Indirect calorimetry served as independent reference method.
The mean error was between −0.6 and 0.8 kcal/min and there were no significant differences between SenseWear and indirect calorimetry at any speed. Differences between body sides in expenditure (mean: −0.2 to 0.0 kcal/min) and step count (mean: −3.4 to 9.7 steps/min) were not significant.
The validity of the SenseWear Armband does not appear to be negatively affected by cerebral palsy during laboratory treadmill exercise. Future field studies are necessary to assess the validity and practicability of energy expenditure and physical activity assessment in children and adolescents with physical disabilities.
Jeffer Eidi Sasaki, Amanda Hickey, Marianna Mavilia, Jacquelynne Tedesco, Dinesh John, Sarah Kozey Keadle and Patty S. Freedson
The purpose of this study was to examine the accuracy of the Fitbit wireless activity tracker in assessing energy expenditure (EE) for different activities.
Twenty participants (10 males, 10 females) wore the Fitbit Classic wireless activity tracker on the hip and the Oxycon Mobile portable metabolic system (criterion). Participants performed walking and running trials on a treadmill and a simulated free-living activity routine. Paired t tests were used to test for differences between estimated (Fitbit) and criterion (Oxycon) kcals for each of the activities.
Mean bias for estimated energy expenditure for all activities was −4.5 ± 1.0 kcals/6 min (95% limits of agreement: −25.2 to 15.8 kcals/6 min). The Fitbit significantly underestimated EE for cycling, laundry, raking, treadmill (TM) 3 mph at 5% grade, ascent/descent stairs, and TM 4 mph at 5% grade, and significantly overestimated EE for carrying groceries. Energy expenditure estimated by the Fitbit was not significantly different than EE calculated from the Oxycon Mobile for 9 activities.
The Fitbit worn on the hip significantly underestimates EE of activities. The variability in underestimation of EE for the different activities may be problematic for weight loss management applications since accurate EE estimates are important for tracking/monitoring energy deficit.
Eric D. Vidoni, Anna Mattlage, Jonathan Mahnken, Jeffrey M. Burns, Joe McDonough and Sandra A. Billinger
The purpose of this study was to determine the validity of a submaximal exercise test, the Step Test Exercise Prescription (STEP), in a broad age range and in individuals in the earliest stages of Alzheimer’s disease (AD). Individuals (n = 102) underwent treadmill-based maximal exercise testing and a STEP. The STEP failed to predict peak oxygen consumption (VO2peak), and was a biased estimate of VO2peak (p < .0001). Only 43% of subjects’ STEP results were within 3.5 ml · kg–1 · min–1 of VO2peak. When categorized into fitness levels these 2 measures demonstrated moderate agreement (kappa = .59). The validity of the STEP was not supported in our participants, including those with AD. The STEP may not be appropriate in the clinic as a basis for exercise recommendations in these groups, although it may continue to have utility in classifying fitness in research or community health screenings.
Joanne Kraenzle Schneider
The purpose of this study was to examine the relationship between self-reported exercise behavior and physiological indicators of exercise behavior (body composition and oxygen consumption measures) in older women. Three self-report exercise behavior instruments were administered in counterbalanced order. Body mass index and sums of skinfold thicknesses were used as measures of body composition. Oxygen consumption was measured using a metabolic cart during a treadmill test while women walked at approximately 70% of their heart rate reserve. Fifty-nine women participated (68.7 ± 6.0 years). Results showed that self-reported exercise behavior was moderately related to body composition measures. However, predicted maximal oxygen consumption was only weakly related to self-reported exercise behavior.
Lucie Péloquin, Pierre Gauthier, Gina Bravo, Guy Lacombe and Jean-Sébastien Billiard
The purposes of the present study were (a) to evaluate the test-retest reliability of the Price et al. (1988) 5-min walking field test, (b) to assess the validity of the test as an estimate of aerobic fitness, and (c) to derive a predictive model for estimating
Nobuo Takeshima, William F. Brechue, Setsuko Ueya and Kiyoji Tanaka
This study attempted to determine the accuracy of measuring heart rate by radial artery palpation in elderly individuals. Elderly (ELD; n = 26) and young (Y; n = 21) individuals completed 3 intensity levels of exercise on a treadmill, each carried out on a separate day. Participants determined their heart rate by palpating the radial artery (PR) after exercise. In ELD, there were significant differences between PR and electrocardiogram (ECG; p = .007). Heart-rate errors at each intensity of exercise were 7.2 ± 12.5, 6.6 ± 15.7, and 10.1 ± 16.5 beats/min. There were no differences in PR and ECG in Y. Fingertip sensitivity was significantly lower in ELD than in Y. A significant, negative correlation existed (r = -.56, n = 26) between heart-rate error and fingertip sensitivity in ELD. These data suggest that self-conducted PR by elderly individuals fails to accurately estimate heart rate. This appears to result from lessened vibrotactile sensitivity in the fingers.
David M. Wert, Jessie M. VanSwearingen, Subashan Perera and Jennifer S. Brach
The purpose of this study was to assess the relative and absolute reliability of metabolic measures of energy expenditure and gait speed during overground walking in older adults with mobility limitations. Thirty-three (mean age [SD] = 76.4 [6.6] years; 66% female) older adults with slow gait participated. Measures of energy expenditure and gait speed were recorded during two 6-min bouts of overground walking (1 week apart) at a self-selected “usual” walking pace. The relative reliability for all variables was excellent: ICC = .81−.91. Mean differences for five of the six outcome variables was less than or equal to the respected SEM, while all six mean differences fell below the calculated MDC95. Clinicians and researchers can be confident that metabolic measures of energy expenditure and gait speed in older adults with slow walking speeds can be reliably assessed during overground walking, providing an alternative to traditional treadmill assessments.
Susan Vincent Graser, Robert P. Pangrazi and William J. Vincent
The purpose was to determine if waist placement of the pedometer effected accuracy in normal, overweight, and obese children, when attaching the pedometer to the waistband or a belt.
Seventy-seven children (ages 10-12 y) wore five pedometers on the waistband of their pants and a belt at the following placements: navel (NV), anterior midline of the right thigh (AMT), right side (RS), posterior midline of the right thigh (PMT), and middle of the back (MB). Participants walked 100 steps on a treadmill at 80 m · min−1.
The RS, PMT, and MB sites on the waistband and the AMT and RS sites on the belt produced the least error.
Of these sites the RS placement is recommended because of the ease of reading the pedometer during activity. Using a belt did not significantly improve accuracy except for normal weight groups at the NV placement site.