Are Older Adults Physically Active Enough - A Matter of Assessment Method? The Generation 100 Study

Conceptualization of a cognitively enriched walking program for older adults: a co-design study with experts and end users

Background

Research in controlled laboratory settings shows that physical activity programs enriched with cognitive challenges enhance the benefits of physical activity on cognition in older adults. This translational study aimed to conceptualise a real-life, cognitively enriched walking program for older adults (65+) by investigating (a) which cognitive tasks are most suited for cognitive enrichment of a walking program, and (b) how to embed these tasks in a walking program to become feasible, enjoyable and effective.

Methods

A co-design process was followed with input of 34 academic experts and 535 end users. First, an online, three-rounds Delphi process was used to obtain consensus amongst academic experts on the key characteristics that a real-life cognitively enriched walking program should have. Next, end users provided feedback and suggestions on what the experts concluded, and gave more insight into their preferences and concerns by means of an online/telephone survey.

Results

Combined input from experts and end users resulted in a list of recommendations to guide the further development of the cognitively enriched walking program. First, it is important to provide a range of cognitive tasks to choose from. Each of these tasks should (a) provide variation and differentiation, (b) be implemented with increasing levels of difficulty, and (c) be integrated in the walk. Second, divide the walk into three parts: 5–10 min brisk walking, cognitive tasks for most of the walk, and 5–10 min free walking. Finally, the program should strive for a minimal session frequency of twice a week, include competition occasionally and carefully, ensure safety and keep the walks fun.

Conclusions

The co-design process resulted in recommendations to guide the next steps in the program development process. Additional studies will be performed to improve the enjoyability and feasibility, and to assess the effectiveness of the cognitively enriched walking program to improve cognitive functioning and physical activity in older adults (65+).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-02823-z.

Association of dog ownership with accelerometer-measured physical activity and daily steps in 70-year-old individuals: a population-based cross-sectional study

Background

Dog ownership (DO) has been associated with higher levels of self-reported walking and physical activity. However, compared to device-based measures, self-reported measures of physical activity may suffer from bias due to recall and social desirability. They are also incapable of quantifying light-intensity physical activity (LPA) and step volume, both of which may have important health benefits, especially for older adults. In this study, we investigated the association of DO with accelerometer-measured physical activity of different intensities and daily steps in 70-year-old individuals.

Methods

This was a population-based cross-sectional study including 1406 participants aged 70 years [54.1% female] who participated in a health survey in Umeå, Sweden between February 2017–November 2019. All participants self-reported DO [yes/no]. Daily averages of LPA, moderate-to-vigorous-intensity physical activity (MVPA), and steps per day [steps/d] were measured for 1 week using hip-mounted Actigraph GT3X+ accelerometers. Associations were investigated using linear- and logistic regression models, adjusted for sociodemographic and health-related factors, date of examination, and accelerometer wear time.

Results

The prevalence of DO was 14.1% [N = 199]. After adjustment for all covariates, DO was associated with 19.2 more minutes/d of LPA [95% CI, 8.8–29.6], 11.4 more minutes/d of MVPA [95% CI, 8.0–14.9] and 1738 more steps/d [95% CI, 1326–2149]. DO was also associated with twice the odds of meeting the physical activity recommendations [OR, 2.07, 95% CI, 1.48–2.90]. Exploratory interaction analyses showed that the association between DO and steps/d was stronger [P_interaction = 0.030] in female [β = 2165, 95% CI, 1585–2744] than in male [β =1255, 95% CI, 664–1845], with a similar trend for MVPA [P_interaction = 0.082].

Conclusions

In this study of community-dwelling 70-year-old individuals, DO was associated with higher levels of daily LPA, MVPA, and steps. With the limitation of the observational design of the study, these findings add knowledge regarding the beneficial role that DO may play for promoting physical activity in the older population. In turn, these findings could support the development and evaluation of targeted interventions seeking to promote dog-friendly environments and facilitate dog walking in the community.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-12401-4.

Methodological aspects for accelerometer-based assessment of physical activity in heart failure and health

Background

For valid accelerometer-assessed physical activity (PA) data, several methodological aspects should be considered. We aimed to 1) visualize the applicability of absolute accelerometer cut-offs to classify PA intensity, 2) verify recommendations to measure PA over 7 days by examining inter-day variability and reactivity, 3) examine seasonal differences in PA, and 4) recommend during which 10 h day period accelerometers should be worn to capture the most PA in patients with heart failure (HEART) and healthy individuals (HEALTH).

Methods

Fifty-six HEART (23% female; mean age 66 ± 13 years) and 299 HEALTH (51% female; mean age 54 ± 19 years) of the COmPLETE study wore accelerometers for 14 days. Aim 1 was analyzed descriptively. Key analyses were performed using linear mixed models.

Results

The results yielded poor applicability of absolute cut-offs. The day of the week significantly affected PA in both groups. PA-reactivity was not present in either group. A seasonal influence on PA was only found in HEALTH. Large inter-individual variability in PA timing was present.

Conclusions

Our data indicated that absolute cut-offs foster inaccuracies in both populations. In HEART, Sunday and four other days included in the analyses seem sufficient to estimate PA and the consideration of seasonal differences and reactivity seems not necessary. For healthy individuals, both weekend days plus four other days should be integrated into the analyses and seasonal differences should be considered. Due to substantial inter-individual variability in PA timing, accelerometers should be worn throughout waking time. These findings may improve future PA assessment.

Trial registration

The COmPLETE study was registered at clinicaltrials.gov (NCT03986892).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12874-021-01350-6.

Physical Activity Level Following Resistance Training in Community-Dwelling Older Adults Receiving Home Care: Results from a Cluster-Randomized Controlled Trial

Older adults' physical activity (PA) is low. We examined whether eight months of resistance training increased PA level in community-dwelling older adults receiving home care. A two-armed cluster-randomized trial using parallel groups was conducted. The included participants were >70 years and received home care. The resistance training group performed resistance training using body weight, elastic bands, and water canes twice per week for eight months. The control group was informed about the national PA guidelines and received motivational talks. The ActiGraph GT3X+ accelerometer was used to estimate PA. Outcomes included total PA (counts per minute), sedentary behavior (min/day), light PA (min/day), moderate-to-vigorous PA (min/day), and steps (mean/day). Between-group differences were analyzed using multilevel linear mixed models. Twelve clusters were randomized to either resistance training (7 clusters, 60 participants) or the control group (5 clusters, 44 participants). A total of 101 participants (median age 86.0 (interquartile range 80-90) years) had valid accelerometer data and were included in the analysis. There were no statistically significant between-group differences for any of the PA outcomes after four or eight months. This study offers no evidence of increased PA level following resistance training in older adults with home care.

Blood Volume, Hemoglobin Mass, and Peak Oxygen Uptake in Older Adults: The Generation 100 Study

Purpose: To investigate the association between blood volume, hemoglobin mass (Hb_mass), and peak oxygen uptake (VO_2peak) in healthy older adults.

Methods: Fifty fit or unfit participants from the prospective randomized Generation 100 Study (n = 1,566) were included (age- and sex-specific VO_2peak above or below average values). Blood, plasma, and erythrocyte volume and Hb_mass were tested using the carbon monoxide rebreathing method within 1 week after VO_2peak testing.

Results: Mean age, BMI, Hb_mass, blood volume, and VO_2peak were 73.0 ± 2.1 years, 24.8 ± 3.3 kg·m², 10.0 ± 1.7 g·kg⁻¹, 76.4 ± 11.8 mL·kg⁻¹, and 33.5 ± 8.4 mL·kg⁻¹·min⁻¹. VO_2peak in fit and unfit participants and women and men were 38.6 ± 6.5 and 25.8 ± 3.8 mL·kg⁻¹·min⁻¹, 30.7 ± 7.6 mL·kg⁻¹·min⁻¹, and 35.5 ± 8.5 mL·kg⁻¹·min⁻¹, respectively. Women were shorter (Δ14 cm), leaner (Δ13 kg), and with less muscle mass (Δ9%) than men (P < 0.05). Relative erythrocyte volume and Hb_mass were lower in women, and blood and erythrocyte volume and Hb_mass were higher in the fit participants (P < 0.05). Hb_mass and erythrocyte volume explained 40 and 37%, respectively, of the variability in VO_2peak, with a limited effect of physical-activity adjustment (40 and 38%, respectively). Blood and plasma volume explained 15 and 25%, respectively, of VO_2peak variability, and the association was strengthened adjusting for physical activity (25 and 31%, respectively), indicating a training-dependent adaptation in plasma but not erythrocyte volume (p ≤ 0.006).

Conclusions: Blood and plasma volumes were moderately associated with VO_2peak in healthy older men and women, and the association was strengthened after adjustment for physical activity. Hb_mass and erythrocyte volume were strongly associated with VO_2peak but unrelated to physical activity.

Associations of Light, Moderate to Vigorous, and Total Physical Activity With the Prevalence of Metabolic Syndrome in 4,652 Community-Dwelling 70-Year-Olds: A Population-Based Cross-Sectional Study

In this cross-sectional study, the authors investigated the associations of objectively measured physical activity (PA) with the prevalence of metabolic syndrome (MetS) in older adults. Accelerometer-derived light-intensity PA, moderate to vigorous PA, and steps per day were measured in (N = 4,652) 70-year-olds in Umeå, Sweden, during May 2012-November 2019. The MetS was assessed according to the American Heart Association/ National Heart, Lung and Blood Institute criteria. The prevalence of MetS was 49.3%. Compared with the reference, the odds ratios for MetS in increasing quartiles of light-intensity PA were 0.91 (0.77-1.09), 0.75 (0.62-0.89), and 0.66 (0.54-0.80). For moderate to vigorous PA, the corresponding odds ratios were 0.79 (0.66-0.94), 0.67 (0.56-0.80), and 0.56 (0.46-0.67). For steps per day, the odds ratios were 0.65 (0.55-0.78), 0.55 (0.46-0.65), and 0.45 (0.36-0.55). In summary, this study shows that greater amounts of PA, regardless of intensity, are associated with lower odds of MetS. With the limitation of being an observational study, these findings may have implications for the prevention of MetS in older adults.

Daily step count and incident diabetes in community-dwelling 70-year-olds: a prospective cohort study

Background

Older adults with diabetes take fewer steps per day than those without diabetes. The purpose of the present study was to investigate the association of daily step count with incident diabetes in community-dwelling 70-year-olds.

Methods

This prospective cohort study included N = 3055 community-dwelling 70-year-olds (52% women) who participated in a health examination in Umeå, Sweden during 2012–2017, and who were free from diabetes at baseline. Daily step count was measured for 1 week using Actigraph GT3X+ accelerometers. Cases of diabetes were collected from the Swedish National Patient Register. The dose-response association was evaluated graphically using a flexible parametric model, and hazard ratios (HR) with 95% confidence intervals (CI) were calculated using Cox regressions.

Results

During a mean follow-up of 2.6 years, diabetes was diagnosed in 81 participants. There was an inverse nonlinear dose-response association between daily step count and incident diabetes, with a steep decline in risk of diabetes from a higher daily step count until around 6000 steps/day. From there, the risk decreased at a slower rate until it leveled off at around 8000 steps/day. A threshold of 4500 steps/day was found to best distinguish participants with the lowest risk of diabetes, where those taking ≥ 4500 steps/day, had 59% lower risk of diabetes, compared to those taking fewer steps (HR, 0.41, 95% CI, 0.25–0.66). Adjusting for visceral adipose tissue (VAT) attenuated the association (HR, 0.64, 95% CI, 0.38–1.06), which was marginally altered after further adjusting for sedentary time, education and other cardiometabolic risk factors and diseases (HR, 0.58, 95% CI, 0.32–1.05).

Conclusions

A higher daily step count is associated with lower risk of incident diabetes in community-dwelling 70-year-olds. The greatest benefits occur at the lower end of the activity range, and much earlier than 10,000 steps/day. With the limitation of being an observational study, these findings suggest that promoting even a modest increase in daily step count may help to reduce the risk of diabetes in older adults. Because VAT appears to partly mediate the association, lifestyle interventions targeting diabetes should apart from promoting physical activity also aim to prevent and reduce central obesity.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-020-09929-2.

Using accelerations of single inertial measurement units to determine the intensity level of light-moderate-vigorous physical activities: Technical and mathematical considerations

Quantifying physical activity and estimating the metabolic equivalent of tasks based on inertial measurement units has led to the emergence of multiple methods and data reduction approaches known as physical activity metrics. The present study aims to compare those metrics and reduction approaches based on descriptive and high order statistics. Data were obtained from 147 young healthy subjects wearing inertial measurement units at their wrist or ankle during standing, walking and running, labeled as light, medium or vigorous activities. The research question was, first, if those metrics allowed differentiating between light, moderate, and vigorous physical activities, and, secondly, what was the relationship with the metabolic equivalent of the task performed. The results showed that each metric differentiated the level of activity and presented a high correlation with the metabolic equivalent of the task. However, each metric and data reduction approach demonstrated its specific statistical characteristics related to the localization of the sensors. Our findings also confirm the absolute necessity to detail explicitly all calculus and post processing of metrics in order to quantify the level of activity by inertial measurement units.

Increasing time spent engaging in moderate-to-vigorous physical activity by community-dwelling adults following a transient ischemic attack or non-disabling stroke: a systematic review

Purpose: The risk of recurrent stroke following a transient ischaemic attack (TIA) or non-disabling stroke is high. Clinical guidelines recommend this patient population accumulate at least 150 minutes of moderate-to-vigorous physical activity each week to reduce the risk of recurrent stroke. We aimed to identify interventions that increase time adults spend in moderate-to-vigorous physical activity following TIA or non-disabling stroke.Method: We searched thirteen databases for articles of secondary prevention interventions reporting outcomes for duration in moderate-to-vigorous physical activity or exercise capacity.Results: Eight trials were identified (n = 2653). Of these, three (n = 198) reported changes in time spent in moderate-to-vigorous physical activity. Only one trial (n = 70), reported significant change in time spent engaging in moderate-to-vigorous physical activity (between-group difference: 11.7 min/day [95% CI 4.07-19.33]) when comparing participation in a six-month exercise education intervention to usual care. No trial measured moderate-to-vigorous physical activity after intervention end.Conclusion: Despite recommendations to participate in regular physical activity at moderate-to-vigorous intensity for secondary stroke prevention, there is very little evidence for effective interventions for this patient population. There is need for clinically feasible interventions that result in long-term participation in physical activity in line with clinical guidelines. Trial registration: Protocol registration: PROSPERO CRD42018092840Implications for rehabilitationThere is limited evidence of the effectiveness of interventions that aim to increase time spent engaging in moderate-to-vigorous physical activity (MVPA) for people following a TIA or non-disabling stroke.A program comprising aerobic and resistance exercises ≥2 per week, supervised by a health professional (supplemented with a home program) over at least 24 weeks appears to be effective in assisting people adhere to recommended levels of moderate to vigorous physical activity after TIA or non-disabling stroke.Secondary prevention programs which include health professional supervised exercise sessions contribute to better adherence to physical activity guidelines; didactic sessions alone outlining frequency and intensity are unlikely to be sufficient.

Measuring physical performance in highly active older adults: associations with age and gender?

BACKGROUND

Higher age is associated with reduced physical capability in the general population. The role of age and gender for physical performance in older adults who exercises regularly is, however, not clear, and there is also a lack of recommendations for outcomes to address physical performance for this population.

AIMS

To explore the associations between physical performance, age and gender, and to examine the suitability and feasibility of clinical field tests for physical performance in active older adults.

METHODS

In this cross-sectional study we included 105 persons, 70-90 years of age, who had exercised regularly for ≥ 12 months. The field tests were Short Physical Performance Battery (SPPB), Timed Up and Go and gait speed for mobility; One-leg standing (OLS) test and Mini-BESTest for balance; Stair test for endurance, 30 s sit-to-stand, and grip strength for muscle strength.

RESULTS

We found associations between age and physical performance, and the associations were slightly stronger for women. Men performed better on tests of muscle strength, balance and endurance, while no gender differences were found in mobility. Grip strength was not associated with mobility tests for men. All tests were feasible, while SPPB and OLS had ceiling and floor effects that limit their suitability in this population.

CONCLUSIONS

Both age and gender were associated with physical performance. We recommend using the gait speed, Mini-BESTest, 30 s sit-to-stand, grip strength and stair tests to assess physical performance in physically active older adults.

Validity Evaluation of the Fitbit Charge2 and the Garmin vivosmart HR+ in Free-Living Environments in an Older Adult Cohort

Background

Few studies have investigated the validity of mainstream wrist-based activity trackers in healthy older adults in real life, as opposed to laboratory settings.

Objective

This study explored the performance of two wrist-worn trackers (Fitbit Charge 2 and Garmin vivosmart HR+) in estimating steps, energy expenditure, moderate-to-vigorous physical activity (MVPA) levels, and sleep parameters (total sleep time [TST] and wake after sleep onset [WASO]) against gold-standard technologies in a cohort of healthy older adults in a free-living environment.

Methods

Overall, 20 participants (>65 years) took part in the study. The devices were worn by the participants for 24 hours, and the results were compared against validated technology (ActiGraph and New-Lifestyles NL-2000i). Mean error, mean percentage error (MPE), mean absolute percentage error (MAPE), intraclass correlation (ICC), and Bland-Altman plots were computed for all the parameters considered.

Results

For step counting, all trackers were highly correlated with one another (ICCs>0.89). Although the Fitbit tended to overcount steps (MPE=12.36%), the Garmin and ActiGraph undercounted (MPE 9.36% and 11.53%, respectively). The Garmin had poor ICC values when energy expenditure was compared against the criterion. The Fitbit had moderate-to-good ICCs in comparison to the other activity trackers, and showed the best results (MAPE=12.25%), although it underestimated calories burned. For MVPA levels estimation, the wristband trackers were highly correlated (ICC=0.96); however, they were moderately correlated against the criterion and they overestimated MVPA activity minutes. For the sleep parameters, the ICCs were poor for all cases, except when comparing the Fitbit with the criterion, which showed moderate agreement. The TST was slightly overestimated with the Fitbit, although it provided good results with an average MAPE equal to 10.13%. Conversely, WASO estimation was poorer and was overestimated by the Fitbit but underestimated by the Garmin. Again, the Fitbit was the most accurate, with an average MAPE of 49.7%.

Conclusions

The tested well-known devices could be adopted to estimate steps, energy expenditure, and sleep duration with an acceptable level of accuracy in the population of interest, although clinicians should be cautious in considering other parameters for clinical and research purposes.

Changes in health-related quality of life in older candidates waiting for kidney transplantation

AIM

There is limited available knowledge regarding health-related quality of life (HRQoL) in older patients with chronic kidney disease. We aimed to describe HRQoL in renal transplant candidates 65 years or older at transplant acceptance, and during the first year on the waiting list.

METHODS

A nationwide prospective observational study in Norway was conducted. HRQoL was evaluated at baseline (wait listing) and after 6 and 12 months using the patient self-reported Kidney Disease and Quality of Life Short form version 1.3. Intra-individual scores at different times were evaluated. Generic HRQoL was compared with scores from an age-matched Norwegian population.

RESULTS

From January 2013 to November 2016, 261 patients ≥65 years accepted for deceased donor kidney transplantation were included. Mean age at inclusion was 71.1 years, 67% male and 69% were on dialysis. HRQoL sum scores significantly decreased during the first year on the waiting list. Physical, mental and kidney disease component summary score reduced from 39.6 to 38.1 (P = 0.045), 48.8 to 44.7 (P < 0.001) and 72.1 to 70.2 (P = 0.03), respectively. When evaluating each domain separately, only the decrease in social function was clinically significant. Age and being on dialysis were the most important predictors for low HRQoL. Compared to the age-matched general population, males had significant lower HRQoL scores. Females were comparable to the general female population at baseline except in general health and vitality.

CONCLUSIONS

HRQoL in older patients waiting for kidney transplantation decreases during the first year on the waiting list, but only the change in social function is clinically significant.

Sedentary behaviour, physical activity, and sarcopenia among older adults in the TSHA: isotemporal substitution model

BACKGROUND

The associations between free-living physical activity (PA) and sedentary behaviour (SB) and sarcopenia in older people and its determinants are controversial. Self-reporting, the use of one-size-fits-all cut-points for intensity categorization when using accelerometers and the absence of a clear sarcopenia definition hampered explorations. The aim of this study is to describe the associations between objectively measured PA patterns and sarcopenia and its determinants.

METHODS

Subjects aged >65 with valid accelerometry and sarcopenia-related measures from Toledo Study of Healthy Aging (TSHA) were included. Muscle mass (MM) was estimated by dual-energy X-ray absorptiometry. Handgrip strength (HS) was measured by dynamometry. Physical performance assessment relied on gait speed (GS). Sarcopenia presence was ascertained using Foundation for the National Institutes of Health (FNIH) criteria. PA and SB were estimated by ActiTrainer worn for 1 week and classified into time spent in SB and different PA intensity bands [light PA (LPA) and moderate-to-vigorous PA (MVPA)] using age-specific cut-points. Different multivariate linear and logistic regression models [(i) single-parameter, (ii) partition, and (iii) isotemporal substitution models] were used for estimating associations between PA, SB, and sarcopenia determinants and sarcopenia rates, respectively. All models adjusted for age, sex, co-morbidities (Charlson index), and functional ability (Katz and Lawton indexes).

RESULTS

Five hundred twelve subjects from the TSHA had available data (78.08 ± 5.71 years of age; 54.3% women). FNIH sarcopenia assessment was performed in 497 subjects (23.3% were sarcopenic). In the linear regression, the single-parameter model showed an association between MVPA and all sarcopenia determinants. In the partition model, MVPA was associated with greater MM and GS. The isotemporal substitution showed that reallocating 1 h/day of MVPA displacing SB was associated with greater values in MM [β = 0.014; 95% confidence interval (CI) = 0.004, 0.024; P < 0.01], GS (β = 0.082; 95% CI = 0.054, 0.110; P < 0.001), and HS (β = 0.888; 95% CI = 0.145, 1.631; P < 0.05). In the logistic regression, the single-parameter model yielded a significant association between 1 h/day increase in MVPA and sarcopenia reduction [odds ratio (OR) = 0.522; 95% CI = 0.367, 0.726; P < 0.001], as did the partition model (OR = 0.555; 95% CI = 0.376, 0.799; P < 0.01). The reallocation of 1 h/day SB only yielded a significant lower sarcopenia risk by almost 50% when it was substituted with MVPA, whereas the substitution of 15 min/day yielded a significant lower sarcopenia risk by 15% (P < 0.001) but did not show any association when it was substituted with LPA.

CONCLUSIONS

An increase in MVPA replacing SB and LPA was associated with a reduction in sarcopenia prevalence and better performance across its determinants (MM, GS, and HS). LPA did not show any significant effect.

Do weather changes influence physical activity level among older adults? - The Generation 100 study

Introduction

Understanding how individual and environmental factors impact physical activity (PA) level is important when building strategies to improve PA of older adults. No studies have examined how hour-to-hour weather changes influence PA in older adults or how the association between weather and PA eventually is related to cardiorespiratory fitness (CRF) measured as peak oxygen uptake. The aim of this study was therefore to examine how hour-to-hour changes in weather effects hour-to-hour PA in a cohort of Norwegian older adults across CRF levels, gender and seasons.

Methods

PA was assessed objectively in 1219 older adults (70–77 years, 51% females) using the Actigraph GT3X+ accelerometer, and quantified as counts·min^-1 (CPM). Weather (Norwegian meteorological Institute) and CRF (MetaMax II) were measured objectively. Panel data analysis added a longitudinal dimension when 110.888 hours of weather- and PA data were analyzed.

Results

Older adults had a higher PA level in warmer (597 CPM) than colder months (556 CPM) (p<0.01). Fixed effects regression-models revealed that increasing temperatures (per hour) influenced PA positively in both colder and warmer months (all, p<0.01), with greater influence in fitter vs. less fit participants (p<0.01). In warmer months, increasing precipitation negatively influenced PA in both unfit females and unfit males (p<0.01). In colder months, increasing precipitation positively influenced PA for moderately fit to fit males (p<0.01), but not for females and unfit males.

Conclusion

To the best of our knowledge, this is the first study to examine the association between weather conditions and objectively-measured-PA among Norwegian older adults. Our findings demonstrates that unfit older adults will be less likely to participate in PA when the weather is unpleasant, compared to those highly fit. The data suggests that the impact of weather should not be ignored when planning public health strategies for increasing PA among older adults.

Adults Engaged in Sports in Early Life Have Higher Bone Mass Than Their Inactive Peers

Purpose: To analyze the relationship between engagement in sports in early life and bone variables among adults of both sexes. Methods: The sample was composed of 225 men and women. Demographic data were collected, and dual-energy X-ray absorptiometry was used to assess bone mineral density, bone mineral content, and lean soft tissue. Sports participation in early life was assessed by an interview including childhood and adolescence. Consumption of tobacco and alcohol was also assessed by interview and the habitual physical activity level by a pedometer. Results: Inactive men had bone mineral content around 11% lower than active men in childhood or adolescence, whereas for women, this difference represented around 14%. Active men had 74% less fat mass than inactive men in early life, and the difference was 67% for women. Early sports participation explained the differences in whole-body bone mineral content (16.8%, P-value = .005) and bone mineral density (8.8%, P-value = .015), as well as bone mineral density in lower limbs (18.9%, P-value = .001) among women. Conclusion: Adults engaged in sports in early life have higher bone mass than their inactive peers, especially women.

Absolute and relative accelerometer thresholds for determining the association between physical activity and metabolic syndrome in the older adults: The Generation-100 study

BACKGROUND

When assessing population adherence to physical activity (PA) recommendation using accelerometers, absolute intensity threshold definition is applied despite having limited validity in those with low cardiorespiratory fitness (CRF), who are unable to reach them (e.g older adults). Thus, PA thresholds relative to CRF may be an alternative approach. We compared the proportion of the older adults meeting the PA recommendation when PA is assessed using absolute versus sex-and-CRF-adjusted (relative) accelerometer thresholds and determined the association between relative versus absolute moderate PA (MPA), vigorous PA (VPA) and moderate-to-vigorous PA (MVPA) and metabolic syndrome (MetS).

METHODS

Cross-sectional study of 509 men and 567 women aged 70-77. Accelerometer assessed MPA, VPA and MVPA were analyzed using absolute and relative thresholds. Meeting the PA-recommendation was defined as amounting ≥150 min/week in MPA/MVPA or 75 min/week in VPA, respectively. CRF was directly measured as peak oxygen uptake (VO_2peak). MetS was defined as 3 or more of the following: elevated waist circumference, fasting glucose, hypertension, triglycerides, decreased HDL-cholesterol or diabetes, dyslipidemia or hypertension medication.

RESULTS

Higher proportion of the population met the recommendation when PA was assessed with relative compared to absolute thresholds: VPA (72.4% vs. 1.7%) and MVPA (75.2% vs. 33.8%). Logistic regression analysis revealed that men and women not meeting the relative-MVPA or VPA recommendation had higher likelihood of MetS (Men: MVPA OR: 1.59, 95% CI: 1.08-2.33.

VPA OR

1.81, 95%CI: 1.23-2.67 and Women: MVPA OR: 2.12, 95% CI: 1.36-3.31; VPA OR: 1.95, 95% CI: 1.29-2.95), compared to men and women meeting the relative MVPA or VPA recommendation. There was no significant association between MetS and absolute MVPA, MPA or VPA recommendations in the fully adjusted model.

CONCLUSIONS

The association between meeting/not meeting the PA recommendation and MetS differed with method. Not meeting relative MVPA and VPA recommendation was associated with significantly higher likelihood for presence of MetS. Since relative intensity is part of the current PA recommendation, it should be considered when assessing population PA and associated health risks in the older adults.

TRIAL REGISTRATION

Clinical Trial Registration: NCT01931111 (Date of trial registration: July 19, 2013).