Steps per day: the road to senior health?

Associations of Morphological Changes in Skeletal Muscles of Preschool Children in China Following Physical Activity

PURPOSE

Physical activity (PA) is likely to be the most important modifiable factor in skeletal muscle development. However, the influence of PA on the skeletal muscle of preschool children has not been thoroughly investigated. The main objective of this study was to quantitatively measure PA, and then, to assess whether associations exist between site-specific muscle changes and PA in relation to sex and weight statuses in preschool children aged 3 to 4 years.

METHODS

A total of 86 healthy preschool children, aged 3-4 years, were instructed to wear an accelerometer for seven consecutive days. The number of steps taken daily, and minutes spent in moderate-vigorous PA (MVPA) and total PA (TPA) were recorded. Muscle thickness was measured by B-mode ultrasonography using a 5-18 MHz scanning head. Muscle thickness was measured at seven sites: the lateral forearm, upper arm, abdomen, anterior and posterior thigh, and anterior and posterior lower leg.

RESULTS

There was no significant difference between boys and girls in terms of MVPA and TPA on weekdays and weekends. According to the linear regression models, after adjusting for daylight duration, the muscle of the posterior thigh was significantly positively associated (p < 0.05) with daily steps and MVPA on weekdays for boys and girls, respectively.

CONCLUSIONS

We found that the muscle thickness of the posterior thigh in preschool children was significantly positively associated with PA, as measured by daily steps and MVPA. We suggest that for the overall health and well-being of preschool children, the levels of PA should be maintained and/or increased, and preferably transformed into a regular part of daily living.

Effect of diabetes mellitus on physical activity in patients with knee osteoarthritis: A cross-sectional study

PURPOSE

Knee osteoarthritis (OA) may be comorbid with diabetes mellitus (DM), and physical activity is a recommended lifestyle strategy for both diseases. The present study investigated the physical activity differences by intensity between knee OA patients with or without DM, and evaluated if physical activity was associated with the presence of DM in knee OA patients.

METHODS

A total of 183 patients (mean age 74.9 ± 6.4 years) with moderate-to-severe knee OA underwent evaluation of knee function (i.e., knee flexion/extension range-of-motion, knee-extension muscle strength, and knee pain), the timed up-and-go (TUG) test, and physical activity measurement using an accelerometer. Physical activity by intensity was compared between knee OA patients with and without DM. The association between physical activity, including knee function and the TUG test time, and DM was assessed.

RESULTS

The 2 groups (with or without DM) did not differ significantly in knee OA severity or age. Compared to knee OA patients without DM, knee OA patients with DM had a significantly lower average daily step count (p < 0.001), and significantly shorter times spent performing light-intensity physical activity (LPA; p < 0.001) and moderate-to-vigorous-intensity physical activity (MVPA; p = 0.006). After adjusting for age, sex, and body mass index, we found that a lower average daily step count and shorter LPA time significantly correlated with DM (β = -0.200, p = 0.006; β = -0.216, p = 0.004, respectively) and a longer TUG test time (β = -0.196, p = 0.014; β = -0.208, p = 0.011, respectively). A shorter MVPA time significantly correlated with lower contralateral knee-extension muscle strength (β = 0.187, p = 0.032).

CONCLUSION

Knee OA patients with DM had significantly lower physical activity levels than those without DM. Furthermore, the presence of DM correlated with a lower step count and a shorter LPA time in knee OA patients.

The association of subjective vision with objectively measured intensity-specific physical activity and bout-specific sedentary behavior among community-dwelling older adults in Japan

PURPOSE

Visual impairment is a possible cause of physical frailty. Reduced physical activity (PA) may be involved in the pathway from visual impairment to physical frailty, although the association between vision and objectively measured PA among older adults remains unclear. This study examined the sex-specific association of subjective vision with intensity-specific PA and bout-specific sedentary behavior (SB) among community-dwelling, older Japanese adults.

STUDY DESIGN

Cross-sectional study METHODS: This study used data from the Neuron to Environmental Impact across Generations study analyzing older adults (527 participants, aged 65-84 years) living in rural areas of Niigata Prefecture, Japan. Subjective vision was assessed by use of a questionnaire. Intensity-specific PA (light-intensity PA and moderate-to-vigorous PA [MVPA]), bout-specific SB, and daily step count were objectively evaluated by use of an accelerometer. The association of subjective vison with PA and SB, stratified by sex, was analyzed by means of general regression analyses, with adjustment for covariates.

RESULTS

The data of 512 participants (men: 46.9%; with poor subjective vision: 22.9%) were analyzed. Poor subjective vision was significantly associated with log MVPA (partial regression coefficient = -0.261, P = .013) and log steps (partial regression coefficient = -0.164; P = .021) among women, whereas a tendency of an association was observed with prolonged SB time among men (partial regression coefficient: 39.1; P = .073).

CONCLUSION

Older Japanese women with poor subjective vision performed less MVPA and had fewer step counts than those of participants with good subjective vision, and men with poor subjective vision had longer prolonged SB, which may all accelerate the process to physical frailty.

Relationships between dietary diversity and gut microbial diversity in the elderly

Diet is considered as a major driver of gut microbiota composition. However, little is known about the relationship between overall dietary balance and gut microbiota, especially in the elderly. Here, using the Quantitative Index for Dietary Diversity (QUANTIDD), we analysed the relationships between dietary diversity and gut microbiota diversity in 445 Japanese subjects aged 65-90 years. We also examined the effect of age by comparing the young-old group aged 65 to 74 years (<75 years group; n=246) and the old-old group aged 75 years and older (≥75 years group; n=199). QUANTIDD showed significant positive relationships with Pielou's evenness and Shannon indices, two α-diversity indices related to the uniformity of species distribution. This suggests that a more diverse diet is associated with a more uniform abundance of various bacterial groups, rather than a greater variety of gut bacteria. QUANTIDD also showed significant positive associations with the abundance of Anaerostipes, Eubacterium eligens group, and Eubacterium ventriosum group, which produce short-chain fatty acids (SCFAs) and are beneficial to health. Negative association was found with the abundance of Ruminococcus gnavus group, which produces inflammatory polysaccharides. Positive associations between QUANTIDD and α-diversity indices or the abundance of specific bacterial groups were identified among all subjects and in the <75 years group, but not in the ≥75 years group. Our results suggest that dietary diversity contributes to the diversity of the gut microbiota and increases the abundance of SCFAs-producing bacteria, but only up to a certain age. These findings help to understand the complex relationship between diet and gut microbiota, and provide hints for specific dietary interventions to promote beneficial gut microbiota in the elderly.

Daily physical activity measured by a wearable activity monitoring device in patients with rheumatoid arthritis

INTRODUCTION

Activities of daily living in patients with rheumatoid arthritis (RA) have been evaluated by patient-reported outcomes. However, it has been difficult to measure activity intensity quantitively. Calories expended, exercise, and steps were measured quantitively by a wearable activity meter, and their associations with patients' background characteristics were examined.

METHODS

Data from a prospective, observational study (CHIKARA study) were used. Eighty-five of 100 RA patients were entered and wore a wearable activity meter for 7 days. The daily calories expended and exercise for both walking and housework and steps were evaluated. Total daily calories expended and exercise was defined as the sum of walking and housework. The relationships of DAS28-ESR, mHAQ, body composition, muscle function, and general status were analyzed.

RESULTS

The median age was 66.0 years, and the disease duration was 5.3 years. DAS28-ESR was 3.11, and mHAQ was 0.125. Total daily calories expended, exercise, and number of steps were 461.7 kcal, 3.97 METs h, and 4,788, respectively. MHAQ, walking speed, power, locomotive syndrome, and frailty were independently related to exercise. Total daily exercise and steps of the moderate and high disease activity group were significantly lower than those of the remission group. When the number of steps was < 3,333 and < 2,468, the odds ratios for locomotive syndrome and frailty increased 14.4-fold and 8.7-fold, respectively, using Fisher's exact test (P < 0.001).

CONCLUSIONS

Daily physical activity and number of steps were significantly decreased in RA patients with moderate and high disease activity as measured by a wearable activity meter. Key Points • Total daily calories expended and exercise for both walking and housework and steps in patients with rheumatoid arthritis were 461.7 kcal, 3.97 METs h, and 4,788, respectively, using a wearable activity meter. • Daily physical activity, especially total daily exercise and number of steps, was significantly decreased in RA patients with moderate and high disease activity. • When total daily steps were < 3,333 and < 2,468, the odds ratios for locomotive syndrome and frailty increased 14.4-fold and 8.7-fold, respectively.

Differences in the Correlation between the Built Environment and Walking, Moderate, and Vigorous Physical Activity among the Elderly in Low- and High-Income Areas

Studies have proved that activity and fitness behaviors are closely related to the quality of life and health status of the elderly. However, different intensities of physical activity (PA)—walking, moderate PA, and vigorous PA—have different correlations with the built environment (BE). This study combines the high and low socioeconomic status (SES) of Guangzhou to establish two types of BE models. The physical activity time of 600 elderly people was collected from questionnaires. Through ArcGIS software, 300 m, 500 m, 800 m, and 1000 m buffer zones were identified, and the land use diversity, street design, population density, distance to destination, distance to public transportation—the five Ds of the BE—were measured. SPSS software was adopted to analyze the correlation between the BE and PA. Results: The PA of people living in low-SES areas was more dependent on the BE, whereas the correlation may be limited in high SES areas. Moreover, in low SES areas, walking was negatively correlated with street connectivity; moderate PA was positively correlated with street connectivity and the shortest distance to the subway station, but negatively correlated with the density of entertainment points of interest (POIs). Studying the relevant factors of the environment can propose better strategies to improve the initiative of the elderly to engage in PA.

Do Older Brazilian Women Who Participate in a Regular Physical Exercise Program Have Higher Habitual Physical Activity Levels? A Cross-Sectional Study Based on Accelerometer Data

A cross-sectional study was conducted to compare the habitual physical activity level, measured by accelerometry, gait performance, assessed by the GAITRite® system, handgrip strength, and static balance between older Brazilian women who participate (n = 50; 70.7 ± 5.5 years) and do not participate (n = 50; 70.1 ± 5.6 years) in a regular physical exercise program, and to investigate whether participation in a regular exercise program ensures compliance with physical activity recommendations. Older women who participated in a regular physical exercise program had significantly shorter sedentary activity time (effect size [ES] = 0.54), longer moderate activity time (ES = 0.85), and higher energy expenditure (ES = 0.64), number of steps (ES = 0.82), gait speed (ES = 0.49), and step length (ES = 0.45). However, regular participation in an exercise program did not guarantee compliance with physical activity recommendations. Behavioral changes to increase physical activity levels among older women who do and do not participate in a regular exercise program are necessary.

Ramadan daily intermittent fasting reduces objectively assessed habitual physical activity among adults

BACKGROUND

Muslims around the world practice intermittent fasting during the month of Ramadan each year. We hypothesized that daily physical activity could be reduced among Muslims due to the inability to refuel and rehydrate in the fasting state.

METHODS

A cohort study design among adults registered with national physical activity community program. Data from a pedometer-based community program was used to extract 3 months of daily step counts before, during, and after Ramadan for the past years (2013-2019). A survey was conducted among participants to determine fasting practice and other health and environmental factors.

RESULTS

A total of 209 participants completed the survey and provided valid data on physical activity. During Ramadan, the average steps per day decreased significantly (- 385 ± SE 158) among participants who fasted (n = 151) p = 0.046 and increased (+ 731 ± SE 247) for the non- fasting participants (n = 58) p = 0.010. Fasting participants preferred before sunset (33.8%) or evening (39.7%) for physical activity. Whereas, non-fasting participants preferred early morning (34.5%).

CONCLUSION

Fasting during Ramadan impacts the daily physical activity behavior among Muslims. Interventions should focus on creating awareness of the importance of maintenance of adequate physical activity for adults fasting during Ramadan.

Effectiveness of the mHealth intervention 'MyDayPlan' to increase physical activity: an aggregated single case approach

Background

e- and mHealth interventions using self-regulation techniques like action and coping planning have the potential to tackle the worldwide problem of physical inactivity. However, they often use one-week self-regulation cycles, providing support toward an active lifestyle on a weekly basis. This may be too long to anticipate on certain contextual factors that may fluctuate from day to day and may influence physical activity. Consequently, the formulated action and coping plans often lack specificity and instrumentality, which may decrease effectiveness of the intervention. The aim of this study was to evaluate effectiveness of a self-regulation, app-based intervention called ‘MyDayPlan’. “MyDayPlan’ provides an innovative daily cycle in which users are guided towards more physical activity via self-regulation techniques such as goal setting, action planning, coping planning and self-monitoring of behaviour.

Methods

An ABAB single-case design was conducted in 35 inactive adults between 18 and 58 years (M = 40 years). The A phases (A1 and A2) were the control phases in which the ‘MyDayPlan’ intervention was not provided. The B phases (B1 and B2) were the intervention phases in which ‘MyDayPlan’ was used on a daily basis. The length of the four phases varied within and between the participants. Each phase lasted a minimum of 5 days and the total study lasted 32 days for each participant. Participants wore a Fitbit activity tracker during waking hours to assess number of daily steps as an outcome. Single cases were aggregated and data were analysed using multilevel models to test intervention effects and possible carry-over effects.

Results

Results showed an average intervention effect with a significant increase in number of daily steps from the control to intervention phases for each AB combination. From A1 to B1, an increase of 1424 steps (95% CI [775.42, 2072.32], t (1082) = 4.31,p < .001), and from A2 to B2, an increase of 1181 steps (95% CI [392.98, 1968.16], t (1082) = 2.94, p = .003) were found. Furthermore, the number of daily steps decreased significantly (1134 steps) when going from the first intervention phase (B1) to the second control phase (A2) (95% CI [− 1755.60, − 512.38], t (1082) = − 3.58, p < .001). We found no evidence for a difference in trend between the two control (95% CI [− 114.59, 197.99], t (1078) = .52, p = .60) and intervention phases (95% CI [− 128.79,284.22], t (1078) = .74, p = .46). This reveals, in contrast to what was hypothesized, no evidence for a carry-over effect after removing the ‘MyDayPlan’ app after the first intervention phase (B1).

Conclusion

This study adds evidence that the self-regulation mHealth intervention, ‘MyDayPlan’ has the capacity to positively influence physical activity levels in an inactive adult population. Furthermore, this study provides evidence for the potential of interventions adopting a daily self-regulation cycle in general.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12966-021-01163-2.

Yearly changes in the composition of gut microbiota in the elderly, and the effect of lactobacilli intake on these changes

The onset and worsening of some diseases are related to the variation and instability of gut microbiota. However, studies examining the personal variation of gut microbiota in detail are limited. Here, we evaluated the yearly variation of individual gut microbiota in 218 Japanese subjects aged 66–91 years, using Jensen-Shannon distance (JSD) metrics. Approximately 9% of the subjects showed a substantial change, as their formerly predominant bacterial families were replaced over the year. These subjects consumed fermented milk products less frequently than their peers. The relationship between the intake frequencies of fermented milk products containing Lacticaseibacillus paracasei strain Shirota (LcS) and JSD values was also investigated. The intra-individual JSD of subjects ingesting LcS products ≥ 3 days/week over the past 10 years was statistically lower than the < 3 days/week group (P = 0.045). Focusing on subjects with substantial gut microbiota changes, only 1.7% of the subjects were included in the LcS intake ≥ 3 days/week group whereas 11.3% were found in the < 3 days/week group (P = 0.029). These results suggest that about one-tenth of the elderly Japanese could experience a substantial change in their gut microbiota during a 1-year period, and that the habitual intake of probiotics may stabilize their gut microbiota.

Multi-Component Intervention Program on Habitual Physical Activity Parameters and Cognitive Function in Patients with Mild Cognitive Impairment: A Randomized Controlled Trial

Age-related dementia refers to a state in which someone experiences multiple cognitive function impairment due to degenerative brain disease, and which causes difficulties in their daily life or social life. Dementia is the most common and serious obstacle in later life. Early intervention in the case of patients who are in the mild cognitive impairment (MCI) stage among the high-risk group can maintain and improve their cognitive function. The purpose of the current trial is aimed at investigating the association between a multi-component (exercise with cognitive) intervention program and habitual physical activity parameters on cognitive functions in MCI patients. Neuropsychological cognitive and depression assessments were performed by neuropsychologists according to normalized methods, including the Korean mini-mental State examination (K-MMSE) and modified Alzheimer's disease assessment scale-cognitive subscale (ADAS-Cog) and cognitive assessment tool (attention, processing speed), and the Korean version of the geriatric depression scale (SGDS-K), both at baseline and at a 12 weeks follow-up. The 12-week multi-component intervention improved cognitive function and habitual physical activity parameters in patients with MCI relative to controls. A multi-component intervention program for patients with MCI is considered to be an effective method of dementia prevention by improving global (ADAS-Cog) and frontal (trail-making test, digit symbol substitution test) cognition and habitual physical activity parameters such as moderate to vigorous physical activity and step count. In addition, it is important to encourage habitual physical activities to ensure that exercise intervention strategies are carried out at the duration and intensity required for improving physical and cognitive wellbeing and obtaining health benefits.

Multisensory integration involved in the body perception of community-dwelling older adults

This study investigates how the multisensory integration in body perception changes with increasing age, and whether it is associated with older adults’ risk of falling. For this, the rubber hand illusion (RHI) and rubber foot illusion (RFI) were used. Twenty-eight community-dwelling older adults and 25 university students were recruited. They viewed a rubber hand or foot that was stimulated in synchrony or asynchrony with their own hidden hand or foot. The illusion was assessed by using a questionnaire, and measuring the proprioceptive drift and latency. The Timed Up and Go Test was used to classify the older adults into lower and higher fall-risk groups. No difference was observed in the RHI between the younger and older adults. However, several differences were observed in the RFI. Specifically, the older adults with a lower fall-risk hardly experienced the illusion, whereas those with a higher fall-risk experienced it with a shorter latency and no weaker than the younger adults. These results suggest that in older adults, the mechanism of multisensory integration for constructing body perception can change depending on the stimulated body parts, and that the risk of falling is associated with multisensory integration.

Older Adults' Daily Step Counts and Time in Sedentary Behavior and Different Intensities of Physical Activity

Background

Daily step count is the simplest measure of physical activity. However, little is known about how daily step count related to time spent in different intensities of physical activity (PA) and sedentary behavior (SB).

Methods

These cross-sectional data were derived from 450 older Japanese adults (56.7% men; mean age, 74.3 years) who were randomly selected from three communities and responded a survey. Daily step count and time spent in moderate-to-vigorous PA (MVPA), light-intensity PA (LPA), and SB were measured using a validated wearable technology (HJA-350IT). Associations of daily step count with time spent in measured behaviors were examined using linear regression models with isometric log-ratio transformations of time-use composition, adjusting for gender, age, and residential area.

Results

Participants averaged 5,412 (standard deviation, 2,878) steps/d and accumulated MVPA, LPA, and SB corresponding to 4.0%, 34.8%, and 61.2% of daily waking time, respectively. Daily step count significantly increased with increase in time spent in MVPA relative to other behaviors (ie, LPA and SB) and in the ratio of LPA to SB after allowing for MVPA. After stratification, daily step count was significantly related to the ratio of LPA to SB in those taking <5,000 steps/d, but not in those taking 5,000–7,499 and ≥7,500 steps/d.

Conclusions

Higher daily step count can be an indicator of not only larger relative contribution of time spent in MVPA, but also higher ratio between LPA and SB, particularly among those who are the least physically active.

Constitutive modeling of menisci tissue: a critical review of analytical and numerical approaches

Menisci are fibrocartilaginous disks consisting of soft tissue with a complex biomechanical structure. They are critical determinants of the kinematics as well as the stability of the knee joint. Several studies have been carried out to formulate tissue mechanical behavior, leading to the development of a wide spectrum of constitutive laws. In addition to developing analytical tools, extensive numerical studies have been conducted on menisci modeling. This study reviews the developments of the most widely used continuum models of the meniscus mechanical properties in conjunction with emerging analytical and numerical models used to study the meniscus. The review presents relevant approaches and assumptions used to develop the models and includes discussions regarding strengths, weaknesses, and discrepancies involved in the presented models. The study presents a comprehensive coverage of relevant publications included in Compendex, EMBASE, MEDLINE, PubMed, ScienceDirect, Springer, and Scopus databases. This review aims at opening novel avenues for improving menisci modeling within the framework of constitutive modeling through highlighting the needs for further research directed toward determining key factors in gaining insight into the biomechanics of menisci which is crucial for the elaborate design of meniscal replacements.

Association Between Toe Flexor Strength and Activity Levels in Community-Dwelling Japanese Older Women

This study aimed to explore the relationship between toe flexor strength and the daily activity levels in 56 Japanese older women aged between 70 and 88 years. The activity levels were measured as the average number of steps/day using a pedometer and the life space assessment (LSA) scores. The Mann-Whitney U test was used to compare toe flexor muscle strength and the LSA scores between those with fewer than and more than 6,000 steps/day. Spearman's correlation coefficient was used to investigate the relationship between toe grip strength according to age and each variable. The LSA scores were significantly higher in the group with >6,000 steps/day (β = 0.188, p < .05). A correlation was found between the number of steps/day and toe flexor strength (r = .424, β = 0.419, p < .05) and the LSA scores (r = .417, β = 0.435, p < .05) in the participants in their 80s. Increasing the number of steps/day may benefit women in their 80s.

Custom-Made Daily Routine Increases the Number of Steps Taken by Frail Older Adults

This study examined whether the number of steps taken by frail older adults increased after two types of interventions (custom-made daily routine [CDR] vs. exercise) were conducted over 12 weeks. The participants were 36 frail older adults aged 84.5 ± 6.0 years who attended a day-care center. They were assigned to one of three groups: CDR (n = 13), home-based exercise (HE, n = 10), or control (CON, n = 13). A wrist-worn accelerometer was used to measure their step count in 24 hr for 6 days. The CDR group demonstrated a daily step count change of approximately 25%, which was significantly higher than that of the CON group (effect size [r] = .51, p = .040). There were no significant changes in the HE group. Thus, a CDR might be useful for increasing the number of steps in frail older adults.

Energy Expenditure in Older Adults Who Are Frail: A Doubly Labeled Water Study

BACKGROUND AND PURPOSE

Frailty is a common and important geriatric syndrome, distinct from any single chronic disease, and an independent predictor of mortality. It is characterized by age-associated decline in physiological reserve and function across multiple systems, culminating in a vicious cycle of altered energy expenditure. The total energy expenditure (TEE) of an individual includes the resting metabolic rate (RMR), the thermic effect of feeding, and the energy expenditure in physical activity (PAEE). The investigation of the energy expenditure of older adults who are frail is essential for better understanding the syndrome. Therefore, we compared the RMR, the PAEE, the physical activity level (PAL), and the TEE of older adults who were frail with those who were not frail.

METHODS

A cross-sectional study was conducted with 26 community-dwelling older adults (66-86 years of age). Older adults in the frail and nonfrail groups were matched for age and gender, and the matched pairs were randomly selected to continue the study. The RMR was measured by indirect calorimetry. The TEE was obtained by the multipoint, doubly labeled water method. After collecting a baseline urine sample, each participant received an oral dose of doubly labeled water composed of deuterium oxide and oxygen-18 (H2O). Subsequently, urine samples were collected on the 1st, 2nd, 3rd, 7th, 12th, 13th, and 14th days after the baseline collection and analyzed by mass spectrometry.

RESULTS AND DISCUSSION

The older adults who were frail presented significantly lower PAEE (1453.7 [1561.9] vs 3336.1 [1829.3] kj/d, P < .01), PAL (1.4 [0.3] vs 1.9 [0.6], P = .04), and TEE (7919.0 [2151.9] vs 10442.4 [2148.0] kj/d, P < .01) than the older adults who were nonfrail. There was no difference in their RMRs (5673.3 [1569.2] vs 6062.0 [1891.7] kj/d, P = .57). Frailty has been associated with a smaller lean body mass and with a disease-related hypermetabolic state, which might explain the lack of difference in the RMR. The PAL of the older adults who were frail was below the recommended level for older adults and determined a lower PAEE and TEE when compared with older adults who were not frail.

CONCLUSION

This study showed that low energy expenditure in physical activity is a main component of frailty. The PAL of the older adults who were frail was far below the recommended level for older adults.

Instrumental activities of daily living and number of daily steps in frail older females

[Purpose] Reportedly, males take fewer steps than females among frail older adults. The step count of frail older adults may be influenced by domestic roles in the instrumental activities of daily living. In this study, we aimed to investigate the association between instrumental activities of daily living and the number of steps in frail older females. [Participants and Methods] In this cross-sectional study, we included 27 frail older females aged 84.4 ± 6.5 years who attended a day-care center. We used the Fillenbaum’s instrumental activities of daily living screener and measured the number of steps using an accelerometer, functional independence measure, grip strength, and short physical performance battery. We investigated the association between instrumental activities of daily living and daily steps. Furthermore, we compared the outcomes of the differences in the independence using a subscale of instrumental activities of daily living. [Results] Instrumental activities of daily living and step counts showed a significant correlation. Participants dependent on meal preparation and housework took significantly fewer steps per day. The dependence of their activities also caused low functional independence measure and weak grip strength. [Conclusion] In frail older females, decreased ability for instrumental activities of daily living were associated with fewer steps. Domestic roles may increase the daily steps in frail older adults.

Independent and Interactive Effects of Habitually Ingesting Fermented Milk Products Containing Lactobacillus casei Strain Shirota and of Engaging in Moderate Habitual Daily Physical Activity on the Intestinal Health of Older People

Infrequent bowel movements decrease the number of beneficial bacteria in the human intestines, thereby potentially increasing the individual's risk of colorectal cancer. The correction of such bowel problems could therefore make an important contribution to improving population health and quality-adjusted lifespan. We examined independent and interactive effects upon the fecal microbiota of two potentially favorable determinants of intestinal motility: the intake frequency of a fermented milk product containing Lactobacillus casei strain Shirota (LcS) and the quantity/quality of habitual physical activity in 338 community-living Japanese aged 65-92 years. Subjects were arbitrarily grouped on the basis of questionnaire estimates of LcS intake (0-2, 3-5, and 6-7 days/week) and pedometer/accelerometer-determined patterns of physical activity [<7000 and ≥7000 steps/day, or <15 and ≥15 min/day of activity at an intensity >3 metabolic equivalents (METs)]. After adjustment for potential confounders, the respective numbers of various beneficial fecal bacteria tended to be larger in more frequent consumers of LcS-containing products, this trend being statistically significant (mostly P < 0.001) for total Lactobacillus, the Lactobacillus casei subgroup, and the Atopobium cluster; in contrast, there were no statistically significant differences in fecal bacterial counts between the physical activity groups. A multivariate-adjusted logistic regression analysis estimated that the risk of infrequent bowel movements (arbitrarily defined as defecating ≤3 days/week) was significantly lower (P < 0.05) in subjects who ingested LcS-containing products 6-7 rather than 0-2 days/week [odds ratio (95% confidence interval) 0.382 (0.149-0.974)] and was also lower in those who took ≥7000 rather than <7000 steps/day [0.441 (0.201-0.971)] or spent ≥15 rather than <15 min/day of physical activity at an intensity >3 METs [0.412 (0.183-0.929)]. The risk of infrequent bowel movements in subjects who combined 6-7 days/week of LcS with ≥7000 steps/day or ≥15 min/day of activity at >3 METs was only a tenth of that for individuals who combined 0-2 days/week of LcS with <7000 steps/day or <15 min/day at >3 METs. These results suggest that elderly individuals can usefully ingest LcS-containing supplements regularly (≥6 days/week) and also engage in moderate habitual physical activity (≥7000 steps/day and/or ≥15 min/day at >3 METs) in order to enhance their gastrointestinal health.

Efficacy of group intervention involving physical activity on subjective well-being of elderly returnees after evacuation following the Great East Japan Earthquake

AIM

In general, physically activity contributes to better subjective well-being (SWB) in the elderly. However, the physical activity level of older people who experienced relocation after the Great East Japan Earthquake has been reported to be low, possibly leading to low SWB. This study aimed to examine the efficacy of group intervention involving physical activity on SWB among older returnees after the Great East Japan Earthquake.

METHODS

The participants were randomly allocated to an intervention group (4 men, 10 women) or a control group (7 women). Participants in the intervention group attended a series of weekly classes over eight weeks to encourage daily physical activity, whereas participants in the control group received no intervention. SWB, the primary outcome, was assessed by the World Health Organization Five Well-Being Index.

RESULTS

Median variation in the World Health Organization Five Well-Being Index scores at 3 months from the baseline in the intervention and control groups was -1.0 and -2.0 points, respectively; the difference was borderline significant (P = 0.06). There was no significant difference between the groups in the median of variation in muscle strength (P = 0.79) or mobility (P = 0.77) at 3 months.

CONCLUSION

The intervention might prevent deterioration in participants' SWB. Further studies involving older returnees with poor physical activity and/or sedentary lifestyle may be beneficial for health promotion in the area.

Promoting Stair Climbing as an Exercise Routine among Healthy Older Adults Attending a Community-Based Physical Activity Program

Stair climbing provides a feasible opportunity for increasing physical activity (PA) in daily living. The purpose of this study was to examine the daily walking and stair-climbing steps among healthy older adults (age: 74.0 ± 4.9 years; Body Mass Index (BMI): 22.3 ± 2.5 kg/m²). Participants (34 females and 15 males) attended a weekly 6-month community-based PA program. During the entire program period, daily walking and stair-climbing steps were recorded using a pedometer (Omron, HJA-403C, Kyoto, Japan). Before and after the 6-month program, height, body weight and leg muscle strength were assessed. After the 6-month program, the mean walking and stair-climbing steps in both women and men increased significantly (p ≤ 0.01). Daily stair-climbing steps increased about 36 steps in women and 47 steps in men. At the end of 6 months, only male participants had significant correlation between the number of stair steps and leg muscle strength (r = 0.428, p = 0.037). This study reported that healthy older adults attending the community-based PA program had regular stair-climbing steps during daily living. Promoting stair climbing as an exercise routine was feasible to increase their walking and stair-climbing steps.

Changes in and Interactions between Physical and Mental Health in Older Japanese: The Nakanojo Study

BACKGROUND

An age-related decrease in functional capacity is consistently reported, but it is not consistently related to a worsening of health-related quality of life (HRQOL) or psychological adjustment. A poor functional capacity and HRQOL have been associated with anxiety or depression, but the possible causal nature and direction of the relationship remain to be explored using long-term longitudinal data.

OBJECTIVE

The purpose of this study was to examine age-related changes in functional capacity, HRQOL, and scores on the Hospital Anxiety and Depression Scale (HADS), and possible causal interrelationships between these variables.

METHODS

Study participants were 5,124 Japanese aged ≥65 years. After the baseline study (2003), annual follow-up observations continued for 10 years. Generalized linear mixed models examined age-related changes in Barthel index (BI), Tokyo Metropolitan Institute of Gerontology Index of Competence (TMIG-IC), HRQOL, and HADS. Cross-lagged effects models tested possible causal interrelationships.

RESULTS

With age, functional capacity and HRQOL scores showed similar declines in both sexes. Changes in mental health, anxiety, and depression developed more slowly than decreases in physical health (BI, TMIG-IC, and physical functioning scores). Cross-lagged effects models demonstrated that functional capacity had positive effects on psychological adjustment, and that psychological adjustment had positive effects on functional capacity 5 years later. Interactions between functional capacity and psychological adjustment showed no sex differences. A decline in functional capacity negatively affected psychological adjustment, but reduced psychological adjustment had no significant impact on functional capacity 5 and 10 years later. Moreover, functional capacity and poor psychological adjustment showed no interactions in either sex.

CONCLUSION

Functional capacity and mood state are interrelated. Greater function could sustain vitality and mental health, possibly reducing anxiety and depression.

Objectively measured habitual physical activity and sleep-related phenomena in 1645 people aged 1-91 years: The Nakanojo Community Study

Relationships between habitual physical activity and sleep-related phenomena were examined in 623 male and 1022 female Japanese participating in the Nakanojo Community Study, using data collected in 2012–2013. Ages ranged from infancy to very old. Daily step count and daily duration of exercise at an intensity >3 metabolic equivalents (METs) were determined by pedometer/accelerometer, 24 h/day for 1 week. Duplicate axillary temperatures were also taken on rising and when retiring. Total bed time was noted, and the efficiency of sleep determined as hours of actual sleep (from a validated pedometer/accelerometer algorithm) divided by bed time. Step counts and especially duration of activity >3 METs peaked in teenagers and decreased as age advanced (p < 0.001). Both axillary temperatures subsequently showed a gradual age-related decline (p < 0.001). The duration and efficiency of sleep also showed a small age-dependent decrease (p < 0.001). Multivariate-adjusted correlation coefficients indicated a better quality of sleep in individuals who took greater habitual physical activity. In individuals aged ≥40 years, these findings were modified by chronic disease conditions including hypertension, diabetes mellitus and hyperlipemia; after controlling statistically for potential confounders, both physical activity and axillary temperature were lower (p < 0.05 or 0.01), and the time spent lying was longer but the efficiency of sleep was poorer (p < 0.01) in those with chronic conditions. These results suggest that habitual physical activity bears an important relationship to sleep-related phenomena at all ages, with a modification of relationships by chronic disease in people aged ≥40 years.

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Habitual physical activity is related to body temperature and sleep patterns.

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Body temperature is higher and sleep quality is better in physically active people.

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In people aged ≥40 years, these relationships are modified by chronic disease.

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Physical activity and body temperature are lower in older people with chronic disease.

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The time spent lying is longer but the quality of sleep is poorer in such people.

Physical Activity and Hippocampal Sub-Region Structure in Older Adults with Memory Complaints

BACKGROUND

Physical activity (PA) plays a major role in maintaining cognition in older adults. PA has been shown to be correlated with total hippocampal volume, a memory-critical region within the medial temporal lobe (MTL). However, research on associations between PA and MTL sub-region integrity is limited.

OBJECTIVE

To examine the relationship between PA, MTL thickness, and its sub-regions, and cognitive function in non-demented older adults with memory complaints.

METHODS

Twenty-nine subjects aged ≥60 years, with memory complaints were recruited for this cross-sectional study. PA was tracked for 7 days using accelerometers, and average number of steps/day determined. Subjects were categorized into two groups: those who walked ≤4000 steps/day (lower PA) and those with >4000 steps/day (higher PA). Subjects received neuropsychological testing and 3T MRI scans. Nonparametric ANCOVAs controlling for age examined differences between the two groups.

RESULTS

Twenty-six subjects aged 72.7(8.1) years completed the study. The higher PA group (n = 13) had thicker fusiform gyrus (median difference = 0.11 mm, effect size (ES) = 1.43, p = 0.001) and parahippocampal cortex (median difference = 0.12 mm, ES = 0.93, p = 0.04) compared to the lower PA group. The higher PA group also exhibited superior performance in attention and information-processing speed (median difference = 0.90, ES = 1.61, p = 0.003) and executive functioning (median difference = 0.97, ES = 1.24, p = 0.05). Memory recall was not significantly different between the two groups.

CONCLUSION

Older non-demented individuals complaining of memory loss who walked >4000 steps each day had thicker MTL sub-regions and better cognitive functioning than those who walked ≤4000 steps. Future studies should include longitudinal analyses and explore mechanisms mediating hippocampal related atrophy.

Objective Longitudinal Measures of Physical Activity and Bone Health in Older Japanese: the Nakanojo Study

OBJECTIVES

To examine dose/response relationships between habitual physical activity and bone health in the elderly.

DESIGN

Longitudinal.

SETTING

Community of Nakanojo.

PARTICIPANTS

Community-living Japanese aged 65 to 84 (212 men, 284 women).

MEASUREMENTS

Daily 24-h pedometer/accelerometer data were collected continuously for 5 years. A quantitative calcaneal osteosonic index (OSI) was determined annually.

RESULTS

Year-end OSI values were higher in those with greater daily step counts and especially a greater duration of activity >3 metabolic equivalents (METs). However, after controlling for baseline OSI, age and body mass, final OSI values were not significantly greater in the fourth than in the third activity quartile, where men and women, respectively, took means of 7,700 and 7,500 steps/day and/or exercised at an intensity >3 METs for means of 19 and 17 min/day. A multivariate-adjusted proportional hazards model predicted that the OSI values of men and women were, respectively, 2.6 (1.4-4.4) and 3.3 (2.1-5.2) and/or 2.8 (1.5-5.6) and 3.9 (2.4-6.7) times more likely to drop below the OSI fracture threshold over 5 years in the two lowest activity quartiles (<7,000 and <6,900 steps/day and/or <18 and <17 min/day at >3 METs) than in the highest quartile (>9,100 and >8,800 steps/day and/or >30 and >25 min/day at >3 METs).

CONCLUSION

After adjustment for potential confounders, the calcaneal health of seniors is associated with both the daily step count and the duration of activity at an intensity >3 METs. The bone health is optimal in elderly people who take at least 7,000-8,000 steps/day and/or spend at least 15-20 min/day at an intensity >3 METs.

Neighbourhood Walkability and Daily Steps in Adults with Type 2 Diabetes

Introduction

There is evidence that greater neighbourhood walkability (i.e., neighbourhoods with more amenities and well-connected streets) is associated with higher levels of total walking in Europe and in Asia, but it remains unclear if this association holds in the Canadian context and in chronic disease populations. We examined the relationships of different walkability measures to biosensor-assessed total walking (i.e., steps/day) in adults with type 2 diabetes living in Montreal (QC, Canada).

Materials and Methods

Participants (60.5±10.4 years; 48.1% women) were recruited through McGill University-affiliated clinics (June 2006 to May 2008). Steps/day were assessed once per season for one year with pedometers. Neighbourhood walkability was evaluated through participant reports, in-field audits, Geographic Information Systems (GIS)-derived measures, and the Walk Score^®. Relationships between walkability and daily steps were estimated using Bayesian longitudinal hierarchical linear regression models (n = 131).

Results

Participants who reported living in the most compared to the least walkable neighbourhoods completed 1345 more steps/day (95% Credible Interval: 718, 1976; Quartiles 4 versus 1). Those living in the most compared to the least walkable neighbourhoods (based on GIS-derived walkability) completed 606 more steps per day (95% CrI: 8, 1203). No statistically significant associations with steps were observed for audit-assessed walkability or the Walk Score^®.

Conclusions

Adults with type 2 diabetes who perceived their neighbourhoods as more walkable accumulated more daily steps. This suggests that knowledge of local neighborhood features that enhance walking is a meaningful predictor of higher levels of walking and an important component of neighbourhood walkability.

The Relationship Between Pedometer-Determined Ambulatory Activity and Balance Variables Within an Older Adult Population

The purpose of this investigation was to determine the differences between gender, physical activity level, and balance in an older adult population. A secondary purpose was to examine the relationship between pedometer-determined ambulatory activity and balance. Forty-six older adults aged 73.7 ± 6.2 years participated in the study. Participants completed the Fullerton Advanced Balance (FAB) Scale and completed a 2-week daily step recording to determine average steps taken per day. Low-level activity participants (<5,000 steps/day) were significantly different from the high-level activity participants (>7,500 steps/day) in weight, age, and the number of medications reported. Males performed better than females on the two-footed jump test and reactive postural test FAB assessments. High-level activity participants performed significantly better than low-level activity participants on all FAB assessments except stand with feet together and eyes closed, reach forward to object, and walk with head turns.

Activity Monitors Step Count Accuracy in Community-Dwelling Older Adults

Objective: To examine the step count accuracy of activity monitors in community-dwelling older adults. Method: Twenty-nine participants aged 67.70 ± 6.07 participated. Three pedometers and the Actical accelerometer step count functions were compared with actual steps taken during a 200-m walk around an indoor track and during treadmill walking at three different speeds. Results: There was no statistical difference between activity monitors step counts and actual steps during self-selected pace walking. During treadmill walking at 0.67 m∙s⁻¹, all activity monitors step counts were significantly different from actual steps. During treadmill walking at 0.894m∙s⁻¹, the Omron HJ-112 pedometer step counts were not significantly different from actual steps. During treadmill walking at 1.12 m∙s⁻¹, the Yamax SW-200 pedometer steps were significantly different from actual steps. Discussion: Activity monitor selection should be deliberate when examining the walking behaviors of community-dwelling older adults, especially for those who walk at a slower pace.

Association between toe grasping strength and accelerometer-determined physical activity in middle-aged and older women

[Purpose] To test the hypothesis that toe grasping strength is associated with daily physical activity in older adults. [Subjects] Fifty-seven Japanese women, aged 52-78 years, volunteered. [Methods] Toe grasping and knee extension strength were measured. Physical activity was also measured, using an accelerometer, and the total duration of each level of exercise intensity (light, moderate, and vigorous) and average step counts were calculated. Subjects were separated into two groups on the basis of accelerometer-determined step counts: LOW (n=28, <8000 steps/day) and HIGH (n=29, ≥8000 steps/day). [Results] Body mass index and body composition (% fat and fat-free mass) were similar between the two groups. Absolute and relative toe grasping strengths (divided by body weight) were greater in HIGH than in LOW. However, both absolute and relative knee extension strength were similar between the groups. Relative toe grasping and knee extension strength correlated with all 3 intensities of physical activity and average step count. After adjusting for age, the duration of light plus moderate physical activity and average step counts correlated to toe grasping strength but not to knee extension strength. [Conclusion] Our results suggest that toe grasping strength may be associated with the amount of light intensity daily physical activity.

Factors describing community ambulation after stroke: a mixed-methods study

Objective:

To develop a model of community ambulation after stroke based on: Canadian data from community-dwelling individuals post-stroke; the experiences and opportunities for community ambulation expressed by individuals with stroke; and current literature. The model presents a visual depiction of the relationships between the different factors of community ambulation after stroke.

Design:

A quantitative/qualitative explanatory sequential mixed-methods design was utilized. Secondary data analysis with structural equation modeling resulted in a community ambulation model. Two focus groups of individuals with stroke were conducted to verify and explain the model.

Setting:

Community.

Subjects:

Quantitative data from 227 participants: 142 (63%) male; 63.4 (12.0) years of age and 2.6 (2.5) years post stroke. Eleven individuals participated in the focus groups: 6 (55%) male; 61.4 (6.9) years of age and 5.8 (3.3) years since stroke.

Main measures:

Model variables: items from the EuroQol, Preference Based Stroke Index, gait speed, Reintegration to Normal Living Index, the Community Health Activities Model Program for Seniors, and the Geriatric Depression Scale.

Results:

The model had reasonable fit with three latent variables: ambulation, gait speed, and health perceptions (normed χ2 = 1.8, root mean square error of approximation = 0.060 (0.043; 0.075)). Depression was also a component of community ambulation. Participants verified the model and added endurance and the environment as additional components. Participants used self-awareness and knowledge of the environment to engage in cognitive strategies related to community ambulation.

Conclusions

A model of community ambulation after stroke was developed and verified. Recognizing important components of community ambulation may assist physiotherapists in determining community ambulation goals, needs, and opportunities in partnership with clients.

Sociodemographic, behavioural and health factors associated with changes in older adults' TV viewing over 2 years

Background

Of all age groups, older adults spend the most time watching TV, which is one of the most common sedentary behaviours. Such sedentary activity in older adulthood is thought to risk deterioration of physical and mental functioning, health and wellbeing. Identifying the characteristics of older adults whose TV viewing increases over time may help to target sedentary behaviour reduction interventions to those in most urgent need. Yet, studies of the factors associated with TV viewing have predominantly been cross-sectional. This study used a prospective design to describe changes in TV viewing over a two-year follow-up period, and to model socio-demographic, behavioural and health factors associated with observed changes in viewing time.

Methods

A two-year follow-up of 6,090 male and female older adults (mean age 64.9 ± 8.9 years) was conducted in the English Longitudinal Study of Ageing, a cohort of community dwelling older adults. TV viewing time was self-reported at baseline and at follow-up. The sample was categorised according to baseline TV viewing duration (<2 hrs/d, 2 < 4 hrs/d, 4 < 6 hrs/d, ≥6 hrs/d), and the observed direction and extent of changes in viewing duration were described for each category. Socio-demographic, behavioural and health variables (socioeconomic status, depressive symptoms, disability, chronic illness, body mass index, physical activity, smoking), as measured at baseline, were entered into regression models as predictors of changes in TV viewing time between baseline and follow-up.

Results

Mean self-reported TV viewing time increased from 5.32 ± 4.08 hrs/d at baseline to 5.53 ± 4.19 hrs/d at follow-up (p < 0.001). Forty-nine per cent of participants increased their TV viewing (23% of all participants by 60 minutes or more), 41% decreased their viewing, and 10% reported no change in viewing duration. Increases in TV viewing at follow-up were associated with lower socioeconomic status, presence of depressive symptoms, higher BMI, physical inactivity, and being a smoker at baseline.

Conclusions

Findings call for the development of effective behaviour change interventions to counter increases in inactive TV viewing among older adults, and point to subgroups who may need to be prioritised for such interventions.

Electronic supplementary material

The online version of this article (doi:10.1186/s12966-014-0102-3) contains supplementary material, which is available to authorized users.

A health care system in transformation: making the case for chiropractic

There are a number of factors that have conspired to create a crisis in healthcare. In part, the successes of medical science and technologies have been to blame, for they have led to survival where lives would previously have been cut short. An informed public, aware of these technological advances, is demanding access to the best that healthcare has to offer. At the same time the burden of chronic disease in an increasing elderly population has created a marked growth in the need for long term care. Current estimates for expenditure predict a rapid escalation of healthcare costs as a proportion of the GDP of developed nations, yet at the same time a global economic crisis has necessitated dramatic cuts in health budgets. This unsustainable position has led to calls for an urgent transformation in healthcare systems.This commentary explores the present day healthcare crisis and looks at the opportunities for chiropractors as pressure intensifies on politicians and leaders in healthcare to seek innovative solutions to a failing model. Amidst these opportunities, it questions whether the chiropractic profession is ready to accept the challenges that integration into mainstream healthcare will bring and identifies both pathways and potential obstacles to acceptance.

Healthy Steps trial: pedometer-based advice and physical activity for low-active older adults

PURPOSE

We compared the effectiveness of 2 physical activity prescriptions delivered in primary care--the standard time-based Green Prescription and a pedometer step-based Green Prescription--on physical activity, body mass index (BMI), blood pressure, and quality of life in low-active older adults.

METHODS

We undertook a randomized controlled trial involving 330 low-active older adults (aged =65 years) recruited through their primary care physicians' patient databases. Participants were randomized to either the pedometer step-based Green Prescription group (n = 165) or the standard Green Prescription group (n = 165). Both groups had a visit with the primary care practitioner and 3 telephone counseling sessions over 12 weeks aimed at increasing physical activity. Outcomes were the changes in physical activity (assessed with the Auckland Heart Study Physical Activity Questionnaire), blood pressure, BMI, quality of life (assessed with the 36-Item Short Form Health Survey), physical function status (assessed with the Short Physical Performance Battery), and falls over a 12-month period.

RESULTS

Of the patients invited to participate, 57% responded. At 12 months, leisure walking increased by 49.6 min/wk for the pedometer Green Prescription compared with 28.1 min/wk for the standard Green Prescription (P=.03). For both groups, there were significant increases across all physical activity domains at 3 months (end of intervention) that were largely maintained after 12 months of follow-up. BMI did not change in either group. Significant improvements in blood pressure were observed for both groups without any differences between them.

CONCLUSIONS

Pedometer use resulted in a greater increase in leisure walking without any impact on overall activity level. All participants increased physical activity, and on average, their blood pressure decreased over 12 months, although the clinical relevance is unknown.

A model to estimate the potential for a physical activity-induced reduction in healthcare costs for the elderly, based on pedometer/accelerometer data from the Nakanojo Study

The rising healthcare costs associated with an aging population have become an urgent fiscal problem. However, evidence of the efficacy of preventive programmes is limited, since almost all studies have involved only small numbers of highly selected participants. This article examines potential physical activity-induced decreases in healthcare expenses, applying a theoretical model to the Nakanojo Study of habitual physical activity and health in an entire elderly community. The Nakanojo Study has shown substantial associations of health with both step count and the duration of moderate effort (intensity >3 metabolic equivalents [METs]). Participants are classed as 'dependent' (n = 800) or 'independent' (n = 4400); the latter category is divided arbitrarily into quartiles, based on physical activity patterns (Q1-Q4; n = 1100 for each quartile). The five groups show a graded prevalence of various morbidities, including dependency, depression, osteoporosis, fractures, hypertension, diabetes mellitus, hyperlipidaemia, ischaemic heart diseases, cerebrovascular diseases, cancer and dementia. Consequently, annual healthcare expenditures (based on 2009 published Japanese costs associated with each of these conditions) differ by about yen (¥)197 900 ($US1979) per person between dependent individuals and those in group Q1, ¥20 700 ($US207) between Q1 and Q2, ¥14 600 ($US146) between Q2 and Q3, and ¥5300 ($US53) between Q3 and Q4. Accepting a causal relationship between physical activity and health, and assuming that an increase in physical activity induces a benefit that is uniform across conditions and diseases, respective morbidity prevalences and associated healthcare costs seem likely to decrease as physical activity increases. Thus, if the physical activity of only 5% of each group could be increased by a single ranking (pedometer/accelerometer scores of 2000 steps/day and 5-10 min/day at >3 METs and/or an adjusted questionnaire score of 10 MET hours/week), one might predict average savings across this population of about ¥12 600 ($US126) per person, or 3.7%, of total medical expenses, including ¥9800 ($US98) of public nursing care insurance costs and an additional ¥2800 ($US28) of national health insurance expenditures. The impact of various changes in the prevalence of physical activity can be simulated using our model. In principle, savings should increase if more people increase their physical activity, and/or the magnitude of individual increases in physical activity is greater. Nevertheless, our analysis suggests that if even a small fraction of individuals in the three least active groups were to make a single-rank increase in their habitual physical activity as a result of focused health support and the promotion of physical activity, a significant reduction in medical expenses might be anticipated, justifying investment in preventive programmes. We now propose to test the validity of the present simulations on a national basis, obtaining accurate and objective evidence of change in individual physical activity patterns using an advanced design of pedometer/accelerometer.

How many steps/day are enough? For older adults and special populations

Older adults and special populations (living with disability and/or chronic illness that may limit mobility and/or physical endurance) can benefit from practicing a more physically active lifestyle, typically by increasing ambulatory activity. Step counting devices (accelerometers and pedometers) offer an opportunity to monitor daily ambulatory activity; however, an appropriate translation of public health guidelines in terms of steps/day is unknown. Therefore this review was conducted to translate public health recommendations in terms of steps/day. Normative data indicates that 1) healthy older adults average 2,000-9,000 steps/day, and 2) special populations average 1,200-8,800 steps/day. Pedometer-based interventions in older adults and special populations elicit a weighted increase of approximately 775 steps/day (or an effect size of 0.26) and 2,215 steps/day (or an effect size of 0.67), respectively. There is no evidence to inform a moderate intensity cadence (i.e., steps/minute) in older adults at this time. However, using the adult cadence of 100 steps/minute to demark the lower end of an absolutely-defined moderate intensity (i.e., 3 METs), and multiplying this by 30 minutes produces a reasonable heuristic (i.e., guiding) value of 3,000 steps. However, this cadence may be unattainable in some frail/diseased populations. Regardless, to truly translate public health guidelines, these steps should be taken over and above activities performed in the course of daily living, be of at least moderate intensity accumulated in minimally 10 minute bouts, and add up to at least 150 minutes over the week. Considering a daily background of 5,000 steps/day (which may actually be too high for some older adults and/or special populations), a computed translation approximates 8,000 steps on days that include a target of achieving 30 minutes of moderate-to-vigorous physical activity (MVPA), and approximately 7,100 steps/day if averaged over a week. Measured directly and including these background activities, the evidence suggests that 30 minutes of daily MVPA accumulated in addition to habitual daily activities in healthy older adults is equivalent to taking approximately 7,000-10,000 steps/day. Those living with disability and/or chronic illness (that limits mobility and or/physical endurance) display lower levels of background daily activity, and this will affect whole-day estimates of recommended physical activity.

Childhood obesity and walking: guidelines and challenges

The development and maintenance of excess body mass in many children is partly attributable to levels of physical activity that are lower than the recommended 60 minutes/day. Walking is a recommended form of physical activity for obese children, due to its convenience and perceived ease of adoption. Unfortunately, studies that have used objective physical activity assessment continue to report low step counts and levels of physical activity in obese children. This may be due to physiological and/or biomechanical factors that make walking more difficult for obese children. The purpose of this review is to highlight the current recommended and measured levels of physical activity for children and to discuss the physiological and biomechanical challenges of walking for obese children that may help explain why these children are not meeting physical activity goals.

Lifestyle and the Respiratory Health of Children

This article offers a review of the potential influences of personal lifestyle on respiratory health in children, looking at both healthy individuals and those with respiratory disorders. As with many aspects of health, regular physical activity, an appropriate diet, and avoidance of obesity and cigarette smoke all contribute to optimal development of the healthy child. An active lifestyle is associated with greater static and dynamic lung volumes, greater efficiency of the ventilatory process, and an optimization of breathing patterns. The risk of upper respiratory infections is also reduced in those maintaining a moderate level of physical activity. Maternal smoking during pregnancy, as well as active and passive smoking, all have an adverse influence on lung function in the child, the largest effects being on dynamic lung volumes. The risk of developing asthma seems reduced in children who maintain a normal body mass and are physically active. A program of graded physical activity is of therapeutic value in a number of established respiratory conditions, including asthma, cystic fibrosis, and ventilatory impairment from neuromuscular disorders. Exercise carries a slight risk of fatalities from asthma and anaphylactic reactions. In designing an optimal physical activity program, it is also important to guard against the hazards of deep oronasal breathing, including the precipitation of bronchospasm by the inhalation of cold, dry air and pollens; an increased exposure to atmospheric pollutants (reducing and oxidant smog, fine and ultra-fine particulates, and carbon monoxide); and possible long-term dangers from chlorine derivatives in the atmosphere of indoor swimming pools.

Habitual physical activity and health in the elderly: the Nakanojo Study

This article provides a detailed overview of both factors influencing habitual physical activity, and relationships between such activity and health in the elderly. Current cross-sectional data from the Nakanojo Study, which we have been carrying out since 2000, indicate substantial associations between the overall health of participants, and both the year-averaged daily step count and the year-averaged daily duration of effort undertaken at an intensity >3 metabolic equivalents (MET). In men, the extent of health is associated more closely with the daily duration of activity >3 MET than with the daily step count, whereas in women the association is closer for the step count than for the duration of activity >3 MET. In both sexes, the threshold amount of physical activity associated with better health is greater for physical than for mental benefits: >8000 vs >4000 steps/day and/or >20 vs >5 min/day at >3 MET, respectively. In other words, physical health is better in those spending at least 20 min/day in moderate walking (at a pace of around 1.4 m/s [5 km/h]) and a further >60 min of light activity per day. In contrast, better mental health is associated with much smaller amounts of deliberate physical activity. Both the intensity and the total volume of physical activity are influenced by meteorological factors, particularly precipitation and mean ambient temperature. Activity decreases exponentially to about 4000 steps/day as precipitation increases. Excluding the influence of rainfall, the daily step count peaks at a mean outdoor temperature of around 17 degrees C; above and especially below such readings, physical activity decreases as a quadratic function of temperature. Seasonal changes in the microclimate should thus be considered when designing interventions intended to increase the habitual physical activity of older adults. Based on these findings, we are now developing preventive tactics that should contribute to health promotion, disease prevention and thus a reduction in medical expenses for elderly people.