Reliability of walking speed in basic and complex conditions in healthy, older community-dwelling individuals.

BACKGROUND: There is a paucity of reliability data for walking speed tests in complex conditions to assess functioning in healthy older individuals. AIMS: To evaluate the absolute intra- and intertest reliability of walking speed performed in basic and complex conditions in healthy older individuals. METHODS: Fifty-two men and women of mean age 69.7 ± 3.2 years were tested for habitual and maximal walking speed. Maximal speed was also assessed under different conditions, including walking on a path of reduced width; picking up objects; stepping over hurdles; stepping over hurdles wearing sunglasses and finally, carrying a box. Two testing sessions (separated by 4 weeks) of two trials each were administered. Reliability was analysed by intra-class correlation coefficient (ICC), minimal detectable change (MDC) and Bland-Altman plots with limits of agreement (LOA). RESULTS: Intrasession ICCs ranged from good to excellent (0.89-0.95) except for picking up objects (0.44). Intersession ICCs were moderate to good (0.60-0.78) and %MDCs were acceptable (14-24%). Bland-Altman plots suggested a good agreement between the two testing sessions at group level (mean differences from - 0.02 to - 0.11 m/s), and limited agreement between testing sessions at individual level (upper LOA from 0.13 to 0.37 m/s and lower LOA from - 0.29 to - 0.49 m/s). CONCLUSIONS: Complex walking speed tests are generally reliable measures displaying good and moderate intra- and inter-session reliability. Such tests seem a more suitable functional assessment tool for heathy older subjects compared with simple walking. Some learning effect may be present and further reliability studies are needed.

Measures of static postural control moderate the association of strength and power with functional dynamic balance.

BACKGROUND AND AIMS: Age-related reductions in strength and power are considered to negatively impact balance control, but the existence of a direct association is still an issue of debate. This is possibly due to the fact that balance assessment is complex, reflects different underlying physiologic mechanisms and involves quantitative measurements of postural sway or timing of performance during balance tasks. The present study evaluated the moderator effect of static postural control on the association of power and strength with dynamic balance tasks. METHODS: Fifty-seven healthy 65-75 year old individuals performed tests of dynamic functional balance (walking speed under different conditions) and of strength, power and static postural control. RESULTS AND CONCLUSIONS: Dynamic balance performance (walking speed) was associated with lower limb strength and power, as well as postural control under conditions requiring postural adjustments (narrow surface walking r(2) = 0.31, p < 0.001). An interaction effect between strength and static postural control was found with narrow surface walking and talking while walking (change of ß 0.980, p < 0.001 in strength for 1 SD improvements in static postural control for narrow walking, and [Formula: see text] -0.730, p < 0.01 in talking while walking). These results indicate that good static postural control facilitates the utilisation of lower limb strength to better perform complex, dynamic functional balance tasks. Practical implications for assessment and training are discussed.

Executive function moderates the role of muscular fitness in determining functional mobility in older adults.

BACKGROUND AND AIMS: Both physical and cognitive factors are known to independently predict functional mobility in older people. However, the combined predictive value of both physical fitness and cognitive factors on functional mobility has been less investigated. The aim of the present study was to assess if cognitive executive functions moderate the role of physical fitness in determining functional mobility of older individuals. METHODS: Fifty-seven 65- to 75-year-old healthy participants performed tests of functional mobility (habitual and maximal walking speed, maximal walking speed while picking up objects/stepping over obstacles), physical fitness (peak power, knee extensors torque, back/lower limb flexibility, aerobic fitness), and executive function (inhibition and cognitive flexibility). RESULTS: Maximal walking speeds were predicted by physical fitness parameters and their interaction with cognitive factors. Knee extensor torque emerged as the main predictor of all tested locomotor performances at maximal speed. The effect of peak power and back/lower limb flexibility was moderated by executive functions. In particular, inhibition and cognitive flexibility differed in the way in which they moderate the role of fitness. High levels of cognitive flexibility seem necessary to take advantage of leg power for walking at maximal speed. In contrast, high levels of inhibitory capacity seem to compensate for low levels of back/lower limb flexibility when picking up movements are added to a locomotor task. CONCLUSIONS: These findings may have important practical implications for the design and implementation of multi-component training programs aimed at optimizing functional abilities in older adults.

Assessment of musculo-articular and muscle stiffness in young and older men.

INTRODUCTION: The aim of this cross-sectional study was to concurrently assess musculo-articular stiffness (MAS) and muscle stiffness (MS) of the knee extensors in younger and older individuals. METHODS: Fourteen young (22.1 ± 3.0 years old) and 12 older (65.4 ± 5.7 years old) men were tested for maximal voluntary contraction (MVC), rate of torque development (RTD), muscle thickness, MAS, and MS of knee extensors. RESULTS: MVC, RTD, and muscle thickness were higher in the younger group (288.6 vs. 194.3 Nm, 1319.5 vs. 787.0 Nm s(-1), 23.1 vs. 17.7 mm, respectively, P < 0.05). MAS normalized to the load supported (30% of MVC) was not different between groups (87.9 vs. 88.5 Nm(-1) kg(-1)), whereas the older group exhibited a higher level of normalized MS (23.2 vs. 18.6 Nm(-1) kg(-1), P < 0.05). CONCLUSIONS: Determinants of MS have been highlighted along with their role in elevated MS. The unaltered level of MAS, which is functionally important in an aging population, might be achieved through a decrease in tendon stiffness.

Physical activity in childhood and bone health.

The aim of this review is to provide a concise overview and update on recent advances in the field of physical activity in childhood and its effects on bone growth with an emphasis on the potential to prevent fractures. In addition, the review poses several unresolved questions in the field for future research.

Physiotherapy for sleep disturbance in chronic low back pain: a feasibility randomised controlled trial.

BACKGROUND: Sleep disturbance is becoming increasingly recognised as a clinically important symptom in people with chronic low back pain (CLBP, low back pain >12 weeks), associated with physical inactivity and depression. Current research and international clinical guidelines recommend people with CLBP assume a physically active role in their recovery to prevent chronicity, but the high prevalence of sleep disturbance in this population may be unknowingly limiting their ability to participate in exercise-based rehabilitation programmes and contributing to poor outcomes. There is currently no knowledge concerning the effectiveness of physiotherapy on sleep disturbance in people with chronic low back pain and no evidence of the feasibility of conducting randomized controlled trials that comprehensively evaluate sleep as an outcome measure in this population. METHODS/DESIGN: This study will evaluate the feasibility of a randomised controlled trial (RCT), exploring the effects of three forms of physiotherapy (supervised general exercise programme, individualized walking programme and usual physiotherapy, which will serve as the control group) on sleep quality in people with chronic low back pain. A presenting sample of 60 consenting patients will be recruited in the physiotherapy department of Beaumont Hospital, Dublin, Ireland, and randomly allocated to one of the three groups in a concealed manner. The main outcomes will be sleep quality (self-report and objective measurement), and self-reported functional disability, pain, quality of life, fear avoidance, anxiety and depression, physical activity, and patient satisfaction. Outcome will be evaluated at baseline, 3 months and 6 months. Qualitative telephone interviews will be embedded in the research design to obtain feedback from a sample of participants' about their experiences of sleep monitoring, trial participation and interventions, and to inform the design of a fully powered future RCT. Planned analysis will explore trends in the data, effect sizes and clinically important effects (quantitative data), and thematic analysis (qualitative data). DISCUSSION: This study will evaluate the feasibility of a randomised controlled trial exploring the effects of three forms of physiotherapy (supervised general exercise programme, individualized walking programme and usual physiotherapy, which will serve as the control group) on sleep quality in people with chronic low back pain. TRIAL REGISTRATION: Current controlled trial ISRCTN54009836.

A possible role for the PPARG Pro12Ala polymorphism in preterm birth.

The links between preterm birth, low birth weight, and adult vascular/metabolic morbidity remain unclear. Genetic susceptibility of babies related to these three conditions might contribute to this long-term association. We tested whether the Pro12Ala polymorphism of the peroxisome proliferator-activated receptor gamma (PPARG) gene could play a role in birth weight and duration of gestation. We genotyped two independent cross-sectional studies from Northern Ireland (n = 382 and 620). In combined populations, the PPARG Ala12 allele was associated (P = 0.03) with lower birth weight, primarily caused by shorter gestational duration (P = 0.04). The frequency of Ala12 allele carriers was higher (P = 0.027) in the group of individuals born before term (35%, n = 60) than in the group of individuals born at term (22%, n = 942). The odds ratios (95% CI) of preterm birth for Ala12 allele carriers were 1.9 (1.1-3.4), P = 0.022, and 4.2 (1.9-9.7), P = 0.0006 (adjusted for sex, maternal age, and study), when considering 37 or 35 weeks of pregnancy as a threshold for preterm birth, respectively. Interestingly, the same allele was also associated with a moderate decreased risk of miscarriages in mothers. In conclusion, the PPARG Pro12Ala polymorphism might represent a genetic susceptibility factor for preterm birth and constitute a link between preterm birth and metabolic diseases later in life.

Evaluating the effects of a low volume stairclimbing programme on measures of health-related fitness in sedentary office workers.

Despite its obvious advantages, few studies have examined health outcomes of regular stariclimbing. In this study, we investigated the training effects of eight weeks of stairclimbing on recognised measures of health-related fitness in an occupational setting. Forty-five public sector employees (22 male, 23 female) aged 42.3 ± 9.0 years were randomly assigned to control (n = 16) or stairclimbing (n = 29) groups. Stairclimbing training began with 1 bout 5d·wk(-1) in week 1, increasing by one climb per day every two weeks until week 5, where a maintenance level of 3 climbs per day was reached. Participants climbed on staircases located within an 8 storey office block, consisting of 145 steps. The prescribed exercise intensity involved climbing the 8 flights of stairs at a rate of 75 steps·min(-1). All participants agreed not to change their diet or lifestyle over the experimental period. Relative to controls, the stairclimbing group showed a significant increase of 9.4% in predicted VO2max (p < 0. 05). No significant changes in blood pressure, blood lipid concentrations or body composition were noted. These findings provide evidence that stairclimbing can enhance an important component of health-related fitness, namely cardiovascular fitness. Given that such improvement resulted from less than 30 minutes per week of moderate exercise, stairclimbing in the workplace should be promoted as a health-enhancing physical activity. Key pointsLow volumes of stairclimbing significantly increased a key component of cardiorespiratory fitness, namely VO2max.Stairclimbing can therefore be promoted within the typical urban workplace as a health enhancing activity.Indices of morphological or metabolic fitness may require larger volumes of stairclimbing than as prescribed in the current study.

Health and Quality of Life Perception in Older Adults: The Joint Role of Cognitive Efficiency and Functional Mobility.

Cognitive and mobility functions are involved in health-related quality of life (HRQoL). The present cross-sectional study aimed at investigating what facets of efficient cognition and functional mobility interactively contribute to mental and physical HRQoL. Fifty-six healthy older individuals (aged 65-75 years) were evaluated for mental and physical HRQoL, core cognitive executive functions (inhibition, working memory, and cognitive flexibility), and functional mobility (walking) under single and dual task conditions. Multiple regression analyses were run to verify which core executive functions predicted mental and physical HRQoL and whether the ability to perform complex (dual) walking tasks moderated such association. Inhibitory efficiency and the ability to perform physical-mental dual tasks interactively predicted mental HRQoL, whereas cognitive flexibility and the ability to perform physical dual tasks interactively predicted physical HRQoL. Different core executive functions seem relevant for mental and physical HRQoL. Executive function efficiency seems to translate into HRQoL perception when coupled with tangible experience of the ability to walk under dual task conditions that mirror everyday life demands. Implications of these results for supporting the perception of mental and physical quality of life at advanced age are discussed, suggesting the usefulness of multicomponent interventions and environments conducive to walking that jointly aid successful cognitive aging and functional mobility.

Supervised walking in comparison with fitness training for chronic back pain in physiotherapy: results of the SWIFT single-blinded randomized controlled trial (ISRCTN17592092).

Effectiveness of brief/minimal contact self-activation interventions that encourage participation in physical activity (PA) for chronic low back pain (CLBP >12 weeks) is unproven. The primary objective of this assessor-blinded randomized controlled trial was to investigate the difference between an individualized walking programme (WP), group exercise class (EC), and usual physiotherapy (UP, control) in mean change in functional disability at 6 months. A sample of 246 participants with CLBP aged 18 to 65 years (79 men and 167 women; mean age ± SD: 45.4 ± 11.4 years) were recruited from 5 outpatient physiotherapy departments in Dublin, Ireland. Consenting participants completed self-report measures of functional disability, pain, quality of life, psychosocial beliefs, and PA were randomly allocated to the WP (n = 82), EC (n = 83), or UP (n = 81) and followed up at 3 (81%; n = 200), 6 (80.1%; n = 197), and 12 months (76.4%; n = 188). Cost diaries were completed at all follow-ups. An intention-to-treat analysis using a mixed between-within repeated-measures analysis of covariance found significant improvements over time on the Oswestry Disability Index (Primary Outcome), the Numerical Rating Scale, Fear Avoidance-PA scale, and the EuroQol EQ-5D-3L Weighted Health Index (P < 0.05), but no significant between-group differences and small between-group effect sizes (WP: mean difference at 6 months, 6.89 Oswestry Disability Index points, 95% confidence interval [CI] -3.64 to -10.15; EC: -5.91, CI: -2.68 to -9.15; UP: -5.09, CI: -1.93 to -8.24). The WP had the lowest mean costs and the highest level of adherence. Supervised walking provides an effective alternative to current forms of CLBP management.

Comparison of the effect of multicomponent and resistance training programs on metabolic health parameters in the elderly.

UNLABELLED: Physical activity interventions such as resistance training (RT) and multicomponent (MCT) exercise training are known to improve functional mobility and reduce the risk of disability among the elderly. Less evidence exists regarding the effectiveness of such exercises to improve metabolic risk factors for age related conditions. This study aimed to compare the effects of MCT and RT programs on metabolic health parameters in healthy elderly. METHODS: Twenty one and 18 subjects completed a 12-week MCT and RT program respectively. Before and after intervention, body composition, functional ability, aerobic fitness and metabolic health parameters including lipid profile, inflammatory markers, glucose metabolism, hormones and growth markers were examined. Circulating concentrations of epidermal growth factor increased significantly in the MCT group from 35.8 ± 29.4 to 56.1 ± 35 pg/ml. High molecular weight adiponectin decreased significantly in the RT group from 4.7 ± 2.9 to 4.2 ± 2.3 µg/ml (p=0.03). No other biochemical parameter was significantly altered within either group. A significant between group difference was found for both ferritin (p=0.02) and EGF (p=0.01), with concentrations of ferritin decreasing in the MCT group and increasing in the RT group and concentration of EGF increasing in the MCT group yet decreasing in the RT group. The MCT program improved results of functional tests including chair stand and habitual walking speed. Present findings suggest that although both the MCT and RT interventions were enough to produce functional and physical benefits, different training programs and/or exercise dose are required to improve metabolic health in healthy older adults.

Exercise prescription in the treatment of type 2 diabetes mellitus : current practices, existing guidelines and future directions.

Exercise is an effective treatment for type 2 diabetes mellitus, resulting in stabilization of plasma glucose in the acute phase and improvements in body composition, insulin resistance and glycosylated haemoglobin with chronic exercise training. However, the most appropriate exercise prescription for type 2 diabetes has not yet been established, resulting from insufficient evidence to determine the optimum type, intensity, duration or frequency of exercise training. Furthermore, patient engagement in exercise is suboptimal. There are many likely reasons for low engagement in exercise; one possible contributory factor may be a tendency for expert bodies to prioritize the roles of diet and medication over exercise in their treatment guidelines. Published treatment guidelines vary in their approach to exercise training, but most agencies suggest that people with type 2 diabetes engage in 150 min of moderate to vigorous aerobic exercise per week. This prescription is similar to the established guidelines for cardiovascular health in the general population. Future possibilities in this area include investigation of the physiological effects and practical benefits of exercise training of different intensities in type 2 diabetes, and the use of individualized prescription to maximize the health benefits of training.

Enhancing cognitive functioning in the elderly: multicomponent vs resistance training.

PURPOSE: The primary purpose of this study was to compare the effects of two different exercise training programs on executive cognitive functions and functional mobility in older adults. A secondary purpose was to explore the potential mediators of training effects on executive function and functional mobility with particular reference to physical fitness gains. METHODS: A sample of 42 healthy community dwelling adults aged 65 to 75 years participated twice weekly for 3 months in either: (1) multicomponent training, prioritizing neuromuscular coordination, balance, agility, and cognitive executive control; or (2) progressive resistance training for strength conditioning. Participants were tested at baseline (T(1)), following a 4-week control period (T(2)), and finally at postintervention (T(3)) for executive function (inhibition and cognitive flexibility) and functional mobility (maximal walking speed with and without additional task requirements). Cardiorespiratory and muscular fitness were also assessed as potential mediators. RESULTS: Indices of inhibition, the functions involved in the deliberate withholding of prepotent or automatic responses, and measures of functional mobility improved after the intervention, independent of training type. Mediation analysis suggested that different mechanisms underlie the effects of multicomponent and progressive resistance training. While multicomponent training seemed to directly affect inhibitory capacity, resistance training seemed to affect it indirectly through gains in muscular strength. Physical fitness and executive function variables did not mediate functional mobility changes. CONCLUSION: These results confirm that physical training benefits executive function and suggest that different training types might lead to such benefits through different pathways. Both types of training also promoted functional mobility in older adulthood; however, neither inhibitory capacity, nor muscular strength gains seemed to explain functional mobility outcomes.

Seasonal and annual variation in young children's physical activity.

INTRODUCTION: It is well established that regular physical activity (PA) contributes to lower levels of morbidity and mortality. However, little is known about the stability of very young children's PA habits across seasons and years. The aims of this study were to 1) examine the influence of season and increasing age on objectively assessed PA in preschool children and 2) examine the stability of young children's PA rankings during 1 yr. METHODS: The PA levels of preschool (3- and 4-yr-old) children were measured, using 6-d pedometer step counts, during winter and spring (n = 85, 52 boys). PA levels were measured again 1 yr after the spring data collection when the children had entered primary school (n = 37, 22 boys). Parents completed questionnaires to assess attitudes toward PA, PA habits, and demographic information in the winter of the first year and the spring of the second year. RESULTS: Young children take approximately 2000 (20%) fewer steps per day in winter than in spring with a rank order stability between the two measures of r = 0.04 (P < 0.01). A modest degree of the observed intrachild or seasonal variation was related to the amount of time fathers played with their children (P < 0.05) and the availability of a safe place for children to play (P < 0.05). Children took approximately 2300 (20%) more steps per day at age 5 compared with age 4 (P < 0.01). The rank order stability of young children's PA during this period was low with correlations ranging from 0.01 to 0.15. CONCLUSIONS: Results suggest that a one-off assessment of PA is unlikely to be representative of a young child's activity during 1 yr and that PA tracks poorly from age 4 to 5.

A genome-wide association meta-analysis identifies new childhood obesity loci.

Multiple genetic variants have been associated with adult obesity and a few with severe obesity in childhood; however, less progress has been made in establishing genetic influences on common early-onset obesity. We performed a North American, Australian and European collaborative meta-analysis of 14 studies consisting of 5,530 cases (≥95th percentile of body mass index (BMI)) and 8,318 controls (<50th percentile of BMI) of European ancestry. Taking forward the eight newly discovered signals yielding association with P < 5 × 10(-6) in nine independent data sets (2,818 cases and 4,083 controls), we observed two loci that yielded genome-wide significant combined P values near OLFM4 at 13q14 (rs9568856; P = 1.82 × 10(-9); odds ratio (OR) = 1.22) and within HOXB5 at 17q21 (rs9299; P = 3.54 × 10(-9); OR = 1.14). Both loci continued to show association when two extreme childhood obesity cohorts were included (2,214 cases and 2,674 controls). These two loci also yielded directionally consistent associations in a previous meta-analysis of adult BMI(1).

Inflammation markers are associated with cardiovascular diseases risk in adolescents: the Young Hearts project 2000.

PURPOSE: The traditional approach for identifying subjects at risk from cardiovascular diseases (CVD) is to determine the extent of clustering of biological risk factors adjusted for lifestyle. Recently, markers of endothelial dysfunction and low grade inflammation, including high sensitivity C-reactive protein (hsCRP), soluble intercellular adhesion molecules (sICAM), and soluble vascular adhesion molecules (sVCAM), have been included in the detection for high risk individuals. However, the relationship of these novel biomarkers with CVD risk in adolescents remains unclear. The purpose of this study, therefore, was to establish the association of hsCRP, sICAM, and sVCAM with CVD risk in an adolescent population. METHODS: Data from the Young Hearts 2000 cross-sectional cohort study, carried out in 1999-2001, were used. From a total of 2,017 male and female participants, 95 obese subjects were identified and matched according to age, sex, and cigarette smoking, with 95 overweight and 95 normal-weight adolescents. Clustered CVD risk was computed using a sum of Z-scores of biological risk factors. The relationship was described using multiple linear regression analyses. RESULTS: hsCRP, sICAM, and sVCAM showed significant associations with CVD risk. hsCRP and sICAM had a positive relation with CVD risk, whereas sVCAM showed an inverse relationship. In this study, lifestyle factors showed no relation with CVD risk. CONCLUSION: The results fit the hypothesized role of low grade inflammation and endothelial dysfunction in CVD risk in asymptomatic adolescents. The inverse relationship of VCAM, however, is hard to explain and indicates the complex mechanisms underlying CVD. Further research is needed to draw firm conclusions on the biomarkers used.

Insulin sensitivity and clustering of coronary heart disease risk factors in young adults. The Northern Ireland Young Hearts Study.

BACKGROUND: Coronary heart disease (CHD) is usually associated with "clustering" of risk factors. Insulin resistance may cause deleterious changes in several CHD risk factors and is of potential interest in the aetiology of clustered risk. We analyzed how glucose and insulin variables were associated with clustered risk. METHODS: Participants were 489 young adults from Northern Ireland. Data were collected between October 1997 and October 1999. Nine risk factors were included in the clustered risk variable. Being "at risk" was defined as being in the upper quartile of risk for a particular risk factor. Subjects with clustered risk were defined as those displaying four or more risk factors. Blood glucose and insulin were measured in the fasting state and 2 h after ingestion of a 75 g glucose load. RESULTS: Fasting insulin and the homeostasis model assessment insulin resistance score (HOMA) were strong, graded predictors of clustered risk. The odds ratio (OR) for having clustered risk was 10.8 (95% CI: 3.6-32.4) for the upper quartile of fasting insulin compared to the lowest quartile, and the corresponding OR for HOMA was 23.2 (95% CI: 5.3-101.6). CONCLUSION: HOMA score predicts clustering of CHD risk factors. Fasting glucose alone did not predict clustering of risk factors, which may indicate that insulin resistance was compensated for by increased insulin secretion.

The effects of 60 minutes of brisk walking per week, accumulated in two different patterns, on cardiovascular risk.

BACKGROUND: Current ACSM guidelines recommend that adults should exercise for 20-60 min on 3-5 days.week(-1) (M.L. Pollock, et al., The recommended quantity and quality of exercise for developing and maintaining cardiorespiratory and muscular fitness, and flexibility in healthy adults. Medicine and Science in Sports and Exercise, 30 (6) (1998) 975-991.). For individuals constrained by a busy lifestyle, an exercise prescription that delivers benefits with the minimum investment of time is attractive. The purpose of the present study, therefore, was to examine the effect of instructing sedentary individuals to undertake 20 min of brisk walking, in two different patterns, 3 days per week, on fitness and other cardiovascular disease (CVD) risk factors. METHODS: Forty-eight subjects (31 women) mean (+/-SD) age 45.7 +/- 9.4 year were randomly assigned to either one 20-min walk (single bout), two 10-min walks (accumulated bouts) 3 days week(-1) for 12-week, or no training (control). Oxygen consumption (VO2), heart rate (HR), and ratings of perceived exertion (RPE) were measured during a 4-stage treadmill test at pre- and post-intervention. Body composition, resting blood pressure and fasting lipoproteins were also assessed. Thirty-two subjects completed the study. RESULTS: There was a significant difference between single-bout and accumulated-bout walkers in the reduction of HR at stages 2 and 3 of the treadmill test from pre- to post-intervention (P < 0.05). There were no differences between groups for changes in VO2 or RPE from pre- to post-intervention. There were also no changes in body mass, adiposity, blood pressure, waist and hip circumferences, or lipid/lipoproteins. CONCLUSION: Brisk walking for 20 min on 3 days of the week fails to alter cardiovascular disease risk factors in previously sedentary adults.

Speed and exercise intensity of recreational walkers.

BACKGROUND: Brisk walking has been identified as an activity suited to meet American College of Sport Medicine/Centers for Disease Control and Prevention recommendations for moderate intensity exercise (55-69% HR(max), 40-59% VO(2)R). However, little is known about whether recreational walkers self-select a pace which elicits this intensity and how they interpret the term "brisk walking." METHODS: The walking speed of 82 adults was covertly observed in a public park. Fifty-nine of these participants demonstrated their interpretation of "brisk walking" and the speed was noted. Eleven of these subjects subsequently walked on a treadmill at their observed and "brisk walk" speeds. Heart rate (HR), respiratory gases, and ratings of perceived exertion (RPE) were measured. RESULTS: Mean observed and "brisk" walking speeds were 1.56 +/- 0.17 m. s(-1) and 1.79 +/- 0.19 m x s(-1) respectively (P < or = 0.001). Mean exercise intensities during the treadmill test (n = 11) were 59.0 +/- 13.4% VO(2max) and 67.3 +/- 11.6% HR(max) for the observed speed (1.60 + 0.24 m x s(-1)). The brisk speed (1.86 +/- 0.12 m x s(-1)) equated to 68.6 +/- 14.9% VO(2max) and 78.5 +/- 15.5% HR(max). CONCLUSION: The speed and intensity selected by this group of walkers meets current recommendations for moderate intensity exercise. Instructing individuals to "walk briskly" prompts more vigorous activity.