Moderate-to-Vigorous Physical Activity But Not Sedentary Time Is Associated With Musculoskeletal Health Outcomes in a Cohort of Australian Middle-Aged Women

Is device-measured physical activity associated with musculoskeletal disorders among young adult Finnish men?

Background

Musculoskeletal (MSK) disorders represent a significant burden to society and can be unpleasant for the affected individuals. Physical activity (PA) can prevent MSK disorders while conferring other health benefits. The present study aimed to investigate associations between device-measured PA and perceived MSK disorders among young adult men.

Methods

PA at different intensity levels, standing, and sedentary behavior were measured with a hip-worn accelerometer in a cohort of 422 young adult Finnish men aged 26 years on average. The incidences of three common MSK disorders (viz., knee pain, lumbar radicular pain, and lumbago pain) during the last month were inquired by a questionnaire. Binary logistic regression was used to examine the associations between the MSK outcomes and explanatory PA variables (PA times at different intensity levels, standing, and sedentary times). The models were controlled for age, education, smoking, BMI, and maximal oxygen uptake.

Results

PA, standing, and sedentary times were not significantly associated with the incidence of perceived MSK pain during the last month, except for lumbago pain. Lumbago pain was slightly more probable if the time spent in light PA increased, even after controlling for potential confounding factors, including moderate-to-vigorous PA, with an odds ratio (OR) of 1.07 (95% CI: 1.02-1.14). Sedentary time showed an opposite association, with an OR of 0.98 (95% CI: 0.96-1.00).

Conclusions

There were neither positive nor negative clinically meaningful associations between PA and recent MSK disorders among young adult men. The result is surprising and requires further confirmation.

Gamified Exercise with Kinect: Can Kinect-Based Virtual Reality Training Improve Physical Performance and Quality of Life in Postmenopausal Women with Osteopenia? A Randomized Controlled Trial

BACKGROUND

Osteopenia, caused by estrogen deficiency in postmenopausal women (PMW), lowers Bone Mineral Density (BMD) and increases bone fragility. It affects about half of older women's social and physical health. PMW experience pain and disability, impacting their health-related Quality of Life (QoL) and function. This study aimed to determine the effects of Kinect-based Virtual Reality Training (VRT) on physical performance and QoL in PMW with osteopenia.

METHODOLOGY

The study was a prospective, two-arm, parallel-design, randomized controlled trial. Fifty-two participants were recruited in the trial, with 26 randomly assigned to each group. The experimental group received Kinect-based VRT thrice a week for 24 weeks, each lasting 45 min. Both groups were directed to participate in a 30-min walk outside every day. Physical performance was measured by the Time Up and Go Test (TUG), Functional Reach Test (FRT), Five Times Sit to Stand Test (FTSST), Modified Sit and Reach Test (MSRT), Dynamic Hand Grip Strength (DHGS), Non-Dynamic Hand Grip Strength (NDHGS), BORG Score and Dyspnea Index. Escala de Calidad de vida Osteoporosis (ECOS-16) questionnaire measured QoL. Both physical performance and QoL measures were assessed at baseline, after 12 weeks, and after 24 weeks. Data were analyzed on SPSS 25.

RESULTS

The mean age of the PMW participants was 58.00 ± 5.52 years. In within-group comparison, all outcome variables (TUG, FRT, FTSST, MSRT, DHGS, NDHGS, BORG Score, Dyspnea, and ECOS-16) showed significant improvements (p < 0.001) from baseline at both the 12th and 24th weeks and between baseline and the 24th week in the experimental group. In the control group, all outcome variables except FRT (12th week to 24th week) showed statistically significant improvements (p < 0.001) from baseline at both the 12th and 24th weeks and between baseline and the 24th week. In between-group comparison, the experimental group demonstrated more significant improvements in most outcome variables at all points than the control group (p < 0.001), indicating the positive additional effects of Kinect-based VRT.

CONCLUSION

The study concludes that physical performance and QoL measures were improved in both the experimental and control groups. However, in the group comparison, these variables showed better results in the experimental group. Thus, Kinect-based VRT is an alternative and feasible intervention to improve physical performance and QoL in PMW with osteopenia. This novel approach may be widely applicable in upcoming studies, considering the increasing interest in virtual reality-based therapy for rehabilitation.

Sedentary behavior does not predict low BMD nor fracture-population-based Canadian Multicentre Osteoporosis Study

Sedentary behavior (SB) or sitting is associated with multiple unfavorable health outcomes. Bone tissue responds to imposed gravitational and muscular strain with there being some evidence suggesting a causal link between SB and poor bone health. However, there are no population-based data on the longitudinal relationship between SB, bone change, and incidence of fragility fractures. This study aimed to examine the associations of sitting/SB (defined as daily sitting time), areal BMD (by DXA), and incident low trauma (fragility) osteoporotic fractures (excluding hands, feet, face, and head). We measured baseline (1995-7) and 10-yr self-reported SB, femoral neck (FN), total hip (TH), and lumbar spine (L1-L4) BMD in 5708 women and 2564 men aged 25 to 80+ yr from the population-based, nationwide, 9-center Canadian Multicentre Osteoporosis Study. Incident 10-yr fragility fracture data were obtained from 4624 participants; >80% of fractures were objectively confirmed by medical records or radiology reports. Vertebral fractures were confirmed by qualitative morphological methods. All analyses were stratified by sex. Multivariable regression models assessed SB-BMD relationships; Cox proportional models were fit for fracture risk. Models were adjusted for age, height, BMI, physical activity, and sex-specific covariates. Women in third/fourth quartiles had lower adjusted FN BMD versus women with the least SB (first quartile); women in the SB third quartile had lower adjusted TH BMD. Men in the SB third quartile had lower adjusted FN BMD than those in SB first quartile. Neither baseline nor stable 10-yr SB was related to BMD change nor to incident fragility fractures. Increased sitting (SB) in this large, population-based cohort was associated with lower baseline FN BMD. Stable SB was not associated with 10-yr BMD loss nor increased fragility fracture. In conclusion, habitual adult SB was not associated with subsequent loss of BMD nor increased risk of fracture.

Longitudinal associations of objectively measured physical activity and sedentary time with leg muscle strength, balance and falls in middle-aged women

We examined the longitudinal associations of accelerometer-measured physical activity and sedentary time with leg muscle strength (LMS), balance, and falls in middle-aged women. This was a 5-year cohort study among 308 women aged 36-56 years. We used linear mixed-effects models to examine associations of baseline and change in accelerometer-measured sedentary time, light physical activity (LPA) and moderate-to-vigorous physical activity (MVPA) with baseline and 5-year change in LMS and balance (timed up and go test [TUG], functional reach test [FRT], lateral reach test [LRT], and step test [ST]), and negative binomial/Poisson and log-binomial regression as appropriate to assess associations with falls after 5-year follow-up. Greater baseline MVPA was associated with better baseline LMS (β = 4.65 kg/SD, 95% CI: 1.37, 7.93) and TUG (β = -0.09 s/SD, 95% CI: -0.18, -0.01) but not with change in them over 5 years. Baseline MVPA was not associated with FRT at baseline but associated with a greater decrease in FRT (β = -0.87 cm/SD, 95% CI: -1.57, -0.17). Increased MVPA over 5 years was associated with less deterioration in FRT (β = 0.88 cm/SD, 95% CI: 0.14, 1.61). Increased sedentary time over 5 years was associated with a larger decrease in FRT (β = -0.82 cm/SD, 95% CI: -1.58, -0.07). Higher baseline LPA was associated with higher falls risk (IRR = 1.27, 95% CI: 1.02, 1.57). Higher baseline MVPA may benefit LMS and balance, while increasing MVPA in the medium term has little effect on change in these outcomes in mid-life. Detrimental association of LPA with falls may be due to greater exposures to environmental hazards.HighlightsOur study for the first time examined the longitudinal associations of objectively measured physical activity and sedentary time with leg muscle strength, balance and falls in middle-aged women.Higher baseline moderate-to-vigorous physical activity (MVPA) may be beneficial for muscle strength and balance at baseline but increasing MVPA in the medium term has little effect on change in LMS or balance outcomes in middle-aged women.Higher baseline light physical activity (LPA) was associated with an increased risk of falls.The detrimental association of LPA with falls may be due to a greater exposure to environmental hazards in midlife, which needs to be clarified in future research.

Tortoise or Hare? The Associations between Physical Activity Volume and Intensity Distribution and the Risk of All-Cause Mortality: A Large Prospective Analysis of the UK Biobank

Analysis methods to determine the optimal combination of volume and intensity of objectively measured physical activity (PA) with prospective outcomes are limited. Participants in UK Biobank were recruited in the UK between 2006 and 2010. We linked the questionnaire and accelerometer with all-cause mortality data from the NHS Information Centre and NHS Central Register up to April 2021. We developed a novel method, extending the penalized spline model of Augustin et al. to a smooth additive Cox model for survival data, and estimated the prospective relationship between intensity distribution and all-cause mortality, adjusting for the overall volume of PA. We followed 84,166 men and women (aged 40-69) for an average of 6.4 years (range 5.3-7.9), with an observed mortality rate of 22.2 deaths per 1000. Survival rates differed by PA volume quartile, with poorer outcomes for the lowest PA volumes. Participants with more sedentary to light intensity PA (<100 milligravities (mg)) and/or less vigorous intensity PA (>250 mg) than average for a given volume of PA, had higher mortality rates than vice versa. Approximate hazard ratios were 0.83 (95% credible interval [CI]: 0.79, 0.88) for an average-risk profile compared to a high-risk profile and 0.80 (95% CI: 0.74, 0.87) for a low-risk profile compared to an average-risk profile. A high- versus low-risk profile has the equivalent of 15 min more slow walking, but 10 min less moderate walking. At low PA volumes, increasing overall volume suggests the most benefit in reducing all-cause mortality risk. However, at higher overall volumes, substituting lighter with more vigorous intensity activity suggests greater benefit.

Development of a Smartphone-Based mHealth Platform for Telerehabilitation

Telerehabilitation is becoming increasingly valuable as a method for expanding medical services. The smartphone-based mHealth platform (SMPT) has been developed to provide high-quality remote rehabilitation through a smartphone and inertial measurement units. The SMPT uses smartphone as a main platform with connection to medical backend server to provide telerehabilitation. Patients would be referred to therapists to receive a tutorial of exercise technique prior to conducting their home exercise. Once patients begin their home exercises, they can report any problems instantly through the SMPT. The medical staff can adjust the exercise program according to patient feedback and the data collected by the SMPT. After completing the exercise program, patients visit their clinician for re-evaluation. A Service User Technology Acceptability Questionnaire from both medical professional and public perspective revealed a high level of agreement on enhanced care, increased accessibility, and satisfaction and a moderate level of agreement on the use of this platform as a substitute for traditional rehabilitation. Concerns about privacy and discomfort were low in the medical professional and public groups. Concerns about care personnel were also significantly different between the two groups. The SMPT is a promising system for providing telerehabilitation as an adjunct to traditional rehabilitation, which may result in improved outcomes compared with those achieved when using traditional rehabilitation alone.

Do simple and quick functional tests reflect a more comprehensive test or physical activity in daily life in healthy young subjects?

ABSTRACT Considering the wide use of functional tests and that faster and simpler evaluations are preferable, this study aimed to verify the association between five protocols of simple functional tests (timed up and go [TUG], four-meter gait speed [4MGS] and sit-to-stand [STS] in five-repetitions [STS5rep], 30-seconds [STS30sec] and one-minute [STS1min] protocols) and the six-minute walk test (6MWT), as well as physical activity in daily life (PADL) in healthy young subjects. In this cross-sectional study, PADL was quantified by a pedometer validated for step counting and we considered the mean of seven consecutive days during the time awake. We assessed functional capacity by the TUG, 4MGS, STS5rep, STS30sec, and STS1min tests and the 6MWT. A total of 79 subjects without lung functional impairments were included (49% male, aged 28 [23-36] years). Performance of simple functional tests correlated with the 6MWT (0.23<r <0.56; P<0.05 for all) and the TUG test showed the best association (R2= 0.34). However, simple functional tests did not correlate with PADL (0.03< r <0.13; P>0.05 for all). The less time-consuming functional tests were weakly-moderately related to the 6MWT in healthy young subjects. The TUG showed the best association and explained up to 34% of the 6MWT. However, the 6MWT cannot be replaced by none of these simple functional tests. Finally, functional capacity showed no association with physical activity in daily life assessed by the pedometers in this population.

Muscle quality indices separately associate with joint-level power-related measures of the knee extensors in older males

PURPOSE

The purpose of this study was to investigate associations of muscle quality indices with joint-level power-related measures in the knee extensors of thirty-two older males (65-88 years).

METHODS

Muscle quality indices included: echo intensity, ratio of intracellular- to total water content (ICW/TW), and specific muscle strength. Echo intensity was acquired from the rectus femoris (EI_RF) and vastus lateralis (EI_VL) by ultrasonography. ICW/TW was computed from electrical resistance of the right thigh obtained by bioelectrical impedance spectroscopy. Specific muscle strength was determined as the normalized maximal voluntary isometric knee extension (MVIC) torque to estimated knee extensor volume. Isotonic maximal effort knee extensions with a load set to 20% MVIC torque were performed to obtain the knee extension power-related measures (peak power, rate of power development [RPD], and rate of velocity development [RVD]). Power and RPD were normalized to MVIC.

RESULTS

There were no significant correlations between muscle quality indices except between EI_RF and EI_VL (|r|≤ 0.253, P ≥ 0.162). EI_RF was negatively correlated with normalized RPD and RVD (r ≤  - 0.361, P ≤ 0.050). ICW/TW was positively correlated with normalized peak power (r = 0.421, P = 0.020). Specific muscle strength was positively correlated with absolute peak power and RPD (r ≥ 0.452, P ≤ 0.012).

CONCLUSION

Knee extension power-related measures were lower in participants with higher EI, lower ICW/TW, and lower specific muscle strength, but the muscle quality indices may be determined by independent physiological characteristics.

Evenness of Dietary Protein Intake Is Positively Associated with Lean Mass and Strength in Healthy Women

Background:

Evenness of protein intake is associated with increased lean mass, but its relationship with muscle strength and performance is uncertain.

Objectives:

We determined the association of evenness of protein intake with lean mass, muscle strength and endurance, and functional ability.

Design:

This was a cross-sectional study.

Setting:

Data were collected at a research university in the upper midwestern United States.

Participants:

One hundred ninety-two healthy women, aged 18 to 79 years, mean ± SEM 41.9 ± 1.3, completed the study.

Measurements:

Dietary intake was assessed using 3-day food diaries verified with food frequency questionnaires. To assess evenness of protein intake, the day was divided into 3 periods: waking to 11:30, 11:31 to 16:30, and after 16:30. Lean mass was measured with dual energy X-ray absorptiometry. Lower-body muscle strength and endurance were determined using isokinetic dynamometry. Upper-body muscle strength was maximal handgrip strength. Functional ability was assessed using 6-m gait speed and 30-second chair stand tests. Accelerometry measured physical activity.

Results:

Intakes of 25 g or more of protein at 1 or more of the 3 periods was positively associated with lean mass (β ± S.E.; 1.067 ± 0.273 kg, P < .001) and upper-body (3.274 ± 0.737 kg, P < .001) and lower-body strength (22.858 ± 7.918 Nm, P = .004) when controlling for age, body mass index, physical activity, and energy and protein intakes. Consuming at least 0.24 g/kg/period for those under 60 years and 0.4 g/kg/period for those 60 years and older was related to lean mass (0.754 ± 0.244 kg, P = .002), upper-body strength (2.451 ± 0.658 kg, P < .001), and lower-body endurance (184.852 ± 77.185 J, P = .018), controlling for the same variables.

Conclusions:

Evenness of protein intake is related to lean mass, muscle strength, and muscular endurance in women. Spreading protein intake throughout the day maximizes the anabolic response to dietary protein, benefiting muscle mass and performance.

Effects of Low-Volume High-Intensity Interval Exercise on 24 h Movement Behaviors in Inactive Female University Students

The purpose of this study was to examine if low-volume, high-intensity interval exercise (HIIE) was associated with changes in 24-h movement behaviors. A quasi-experimental study design was used. We collected accelerometry data from 21 eligible participants who consistently wore an ActiGraph for a period of two-weeks. Differences in behaviors were analyzed using a paired t-test and repeated measures analysis of variance. Regression analysis was used to explore relationships with factors that impacted changes. The results indicated a compensatory increase in sedentary time (ST) (4.4 ± 6.0%, p < 0.01) and a decrease in light-intensity physical activity (LPA) (−7.3 ± 16.7%, p < 0.05). Meanwhile, moderate-intensity physical activity (MPA), vigorous-intensity physical activity (VPA), and total physical activity (TPA) increased following exercise (p < 0.001). Sleep duration and prolonged sedentary time were reduced (p < 0.05). Exercise intensity and aerobic capacity were associated with changes in ST. The results from the study indicate that participating in a low-volume HIIE encouraged participants who were previously inactive to become more active. The observations of increases in ST may have displaced a prolonged sitting time. The decrease in sleeping time observed may be reflecting an increased sleep quality in connection with increased higher-intensity PA.

The Role of Daily Step Count in Determining Risk Factors for Falls

Falls risk is often assessed without considering exposure to risk. We examined the risk factors associated with falls in those with greater and lower levels of daily step count. Falls were recorded over 12 months using bimonthly calendars in community-dwelling older people (mean age 72.0, SD 6.9). Daily step count was measured using a pedometer worn consecutively for 7 days. A cut score of <5,575.5 steps/day was used to identify people with lower step count. Negative binominal models were used to identify cognitive, medical, and sensorimotor factors associated with falls in those with higher versus lower levels of daily step count. In those with lower daily step count, poorer executive function, slower gait speed, and lower steps per day were associated with increased falls risk. In those with higher step count, only mood was associated with increased falls risk. Considering daily step count is important when assessing falls risk in older people.

Influence of Physically Active or Sedentary Lifestyle on Postural Control of Community-dwelling Old Adults

Objectives: The maintenance of the postural balance is fundamental for the daily living activities, as well as for the practice of physical exercise. However, the aging process and sedentary behavior (i.e., large sitting time) lead to changes biological systems, impairing postural balance with consequent increased falls risk. On the other hand, physical activity practice is a protective factor against these trends. The aim of this study is to investigate the influence of physical activity profile and sedentary behavior on postural control in community-dwelling old adults.Methods: This is a cross-sectional study including 208 community-dwelling old adults, which were stratified as sufficiently or insufficiently physically active and with or without sedentary behavior. Then, they were grouped as follow: G1 (sufficiently physically active and without sedentary behavior), G2 (insufficiently physically active, but without sedentary behavior), G3 (sufficiently physically active, but with sedentary behavior), and G4 (insufficiently physically active and with sedentary behavior).Results: Stabilometric parameters (sway area, total length of center of pressure [CoP] trajectory, and the mean velocity of CP displacement) were obtained to evaluate the postural control. There was significant difference between G1 and G4 on mean velocity of CoP displacement (p < 0.05).Conclusions: The coexistence of sedentary behavior and insufficient physically active profile seem to impact negatively on postural control.

Preserved skeletal muscle oxidative capacity in older adults despite decreased cardiorespiratory fitness with ageing

KEY POINTS

Healthy older adults exhibit lower cardiorespiratory fitness ( V ̇ O 2 peak ) than young in the absence of any age-related difference in skeletal muscle mitochondrial capacity, suggesting central haemodynamics plays a larger role in age-related declines in V ̇ O 2 peak . Total physical activity did not differ by age, but moderate-to-vigorous physical activity was lower in older compared to young adults. Moderate-to-vigorous physical activity is associated with V ̇ O 2 peak and muscle oxidative capacity, but physical inactivity cannot entirely explain the age-related reduction in V ̇ O 2 peak .

ABSTRACT

Declining fitness ( V ̇ O 2 peak ) is a hallmark of ageing and believed to arise from decreased oxygen delivery and reduced muscle oxidative capacity. Physical activity is a modifiable lifestyle factor that is critical when evaluating the effects of age on parameters of fitness and energy metabolism. The objective was to evaluate the effects of age and sex on V ̇ O 2 peak , muscle mitochondrial physiology, and physical activity in young and older adults. An additional objective was to assess the contribution of skeletal muscle oxidative capacity to age-related reductions in V ̇ O 2 peak and determine if age-related variation in V ̇ O 2 peak and muscle oxidative capacity could be explained on the basis of physical activity levels. In 23 young and 52 older men and women measurements were made of V ̇ O 2 peak , mitochondrial physiology in permeabilized muscle fibres, and free-living physical activity by accelerometry. Regression analyses were used to evaluate associations between age and V ̇ O 2 peak , mitochondrial function, and physical activity. Significant age-related reductions were observed for V ̇ O 2 peak (P < 0.001), but not muscle mitochondrial capacity. Total daily step counts did not decrease with age, but older adults showed lower moderate-to-vigorous physical activity, which was associated with V ̇ O 2 peak (R²  = 0.323, P < 0.001) and muscle oxidative capacity (R²  = 0.086, P = 0.011). After adjusting for sex and physical activity, age was negatively associated with V ̇ O 2 peak but not muscle oxidative capacity. Healthy older adults exhibit lower V ̇ O 2 peak but preserved mitochondrial capacity compared to young. Physical activity, particularly moderate-to-vigorous, is a key factor in observed age-related changes in fitness and muscle oxidative capacity, but cannot entirely explain the age-related reduction in V ̇ O 2 peak .

Neither leg muscle strength nor balance are associated with the incidence of falls in middle-aged women: A 5-year population-based prospective study

BACKGROUND

Muscle strength and balance are major modifiable factors of falls in older adults, but their associations with falls in middle-aged adults are under investigated. We aimed to examine the association of baseline and change in leg muscle strength (LMS) and balance with the incidence of falls in a cohort of middle-aged women.

METHODS

This was a five-year follow-up of a population-based sample of 273 women aged 36-57 years at baseline (2011-2012). Data on LMS (by dynamometer) and balance (timed up and go test [TUG], step test [ST], functional reach test [FRT], and lateral reach test [LRT]) were obtained at baseline and five years later (2017-2018). After five years, falls were recorded monthly for one year by questionnaire (2017-2019). Negative binomial/Poisson and log binomial regressions were used as appropriate to assess associations of baseline and change in LMS and balance with any falls, injurious falls and multiple falls.

RESULTS

Over one-year, 115 participants (42%) reported at least one fall. Neither baseline nor 5-year change in LMS and balance measures were associated with the risk of any falls, injurious falls, or multiple falls five years later, with or without adjusting for confounders at baseline (incidence rate ratio/relative risk ranging from 0.85 to 1.19, 0.90 to 1.20, and 0.82 to 1.36, respectively; P>0.05 for all).

CONCLUSIONS

Baseline or change in LMS and balance measures are not associated with incident falls among middle-aged women. The contributions of environmental and other intrinsic factors such as chronic conditions and gait/mobility problems need to be investigated.

The association between physical activity intensity, cognition and brain structure in people with type 2 diabetes

BACKGROUND

Physical inactivity is a risk factor for type 2 diabetes (T2D) and dementia. However, it is unknown if physical activity (PA) intensity is associated with brain health in people with T2D. Therefore, this study aimed to determine 1) associations between PA intensity and step count with both cognition and brain structure and 2) if apolipoprotein E-ε4 (APOE-ε4) or insulin-therapy modifies any associations.

METHODS

Participants were people with T2D (n=220; aged 55-86 years). An accelerometer worn over the left hip was used to obtain step count and moderate-to-vigorous PA (MVPA) averaged over 7 days. Cognition in 7 domains was obtained using a battery of neuropsychological tests. Brain structure was measured by Magnetic Resonance Imaging (MRI). Linear regression models were used to examine associations between step count, MVPA and each cognitive and MRI measure. APOE-ε4 x PA and insulin-therapy x PA product terms were added to the models to examine effect modification.

RESULTS

The mean age of participants was 67.9 (SD 6.3). Higher step count was associated with greater hippocampal volume (β=0.028 95%CI 0.005, 0.051). Insulin-therapy modified the association between MVPA and attention-processing speed, such that associations were significant in people receiving insulin-therapy (P for interaction=0.019). There were no other significant associations.

CONCLUSIONS

Higher step count and greater time spent in MVPA may be associated with better hippocampal volume and attention-processing speed respectively in people with T2D. People with greater diabetes severity (receiving insulin-therapy) may get more cognitive benefit from MVPA.

The physiological benefits of sitting less and moving more: Opportunities for future research

Sedentary behavior (SB) and physical activity (PA) are important risk factors of cardiovascular disease morbidity and mortality. In addition to increasing the amount of moderate-to-vigorous PA (MVPA), the current PA guidelines recommend that adults should reduce SB, or any waking activity performed while sitting, reclining, or lying, with low energy expenditure. While mounting evidence has emphasized the benefits of increasing MVPA, little has focused on the effect of SB on health. Therefore, this review discusses the pathophysiological effects of SB and the potential physiological benefits of reducing/breaking up SB at the levels below the current guidelines for PA. Such knowledge is important, given that the majority of the United States population performs insufficient or no MVPA and is at high risk of being negatively impacted by SB. Interventions targeting sedentary time, such as breaking up SB by standing and moving, may be safe, feasible, and applicable to execute daily for a wide range of the population. This review also discusses the importance of monitoring SB in the era of the coronavirus disease 2019 (COVID-19) pandemic and the clinical implications of sitting less and moving more.

Associations of sitting and physical activity with grip strength and balance in mid-life: 1970 British Cohort Study

Strength and balance training are now recommended in many physical activity (PA) guidelines. However, it is unclear whether these recommendations are applicable to middle-aged adults. We aimed to examine the associations of sitting and physical activity times with grip strength and standing balance performance in mid-life. Up to 4726 participants from the 1970 British Cohort study, with data on sitting and activity (measured using a thigh-worn accelerometer (activPAL3-micro)), grip strength and balance times at age 46 years were included in analyses. Associations of sitting, moderate-vigorous, and total PA times with grip strength and balance performance were tested using linear and multinomial logistic regression models, respectively. Greater time spent sitting was associated with weaker grip strength even after adjustment for potential confounders and MVPA time (fully adjusted regression coefficient: -0.51 kg (95% CI: -0.63, -0.39) per 1-hour sitting/day). Associations of PA time with grip strength were not independent of sitting time. There was only a weak association between sitting time and balance performance but greater MVPA and total PA times were associated with higher relative risks of successfully balancing for 30 seconds with eyes closed (vs poor balance). However, these associations were fully attenuated after adjustments for covariates. In summary, among a sample of middle-aged adults a robust association between sitting time and grip strength was observed. These findings suggest potential benefits of actively promoting less sitting alongside activities that specifically benefit muscle strength and balance performance in mid-life to ensure that people maintain all important aspects of their physical capability as they age.

Objectively Measured Sedentary Behavior and Physical Fitness in Adults: A Systematic Review and Meta-Analysis

Background: Sedentary behavior has been considered an independent risk factor to health. The aim of this systematic review and meta-analysis was to examine associations between objectively measured sedentary time and physical fitness components in healthy adults. Methods: Four electronic databases (Web of Science, Scopus, Pubmed and Sport Discus) were searched (up to 20 September 2020) to retrieve studies on healthy adults which used observational, cohort and cross-sectional designs. Studies were included if sedentary time was measured objectively and examined associations with the health- or skill-related attributes of physical fitness (e.g., muscular strength, cardiorespiratory fitness, balance). After applying additional search criteria, 21 papers (11,101 participants) were selected from an initial pool of 5192 identified papers. Results: Significant negative associations were found between total sedentary time with cardiorespiratory fitness (r = −0.164, 95%CI: −0.240, −0.086, p < 0.001), muscular strength (r = −0.147, 95%CI: −0.266, −0.024, p = 0.020) and balance (r = −0.133, 95%CI: −0.255, −0.006, p = 0.040). Conclusions: The evidence found suggests that sedentary time can be associated with poor physical fitness in adults (i.e., muscular strength, cardiorespiratory fitness and balance), so strategies should be created to encourage behavioral changes.

Sedentary Patterns Are Associated with Bone Mineral Density and Physical Function in Older Adults: Cross-Sectional and Prospective Data

Aging causes some unfavorable morphological and functional changes, such as the decline in bone mineral density (BMD) and physical function. Moderate-to-vigorous physical activity (MVPA) and sedentary time seem to be related with these alterations, but the impact of distinct patterns remains unclear. The aim of this study was to cross-sectionally and prospectively assess the association between objectively measured MVPA and sedentary patterns (bouts and breaks) with BMD and physical function in older adults. The study considered 151 Brazilians (aged ≥ 60 years), out of which 68 participants completed 2-year follow-up measurements. MVPA and sedentary patterns were measured by means of accelerometry, BMD-(total proximal femur and lumbar spine (L1-L4)) by means of dual-energy X-ray absorptiometry (DXA), and physical function-by means of physical tests. In older women, sedentary bouts >60 min were inversely associated with handgrip strength (β = -2.03, 95% CI: from -3.43 to -0.63). The prospective analyses showed that changes in sedentary bouts (20 to 30 min and >60 min) were inversely associated with changes in the lumbar spine's BMD (β = -0.01, 95% CI: from -0.01 to -0.00 and β = -0.03, 95% CI: from -0.06 to -0.01) and the lumbar spine's T-score (β = -0.06, 95% CI: from -0.10 to -0.01 and β = -0.27, 95% CI: from -0.49 to -0.04), respectively. In older women, sedentary patterns are cross-sectionally associated with handgrip strength and prospectively associated with BMD independent of MVPA.

Life satisfaction and musculoskeletal complaints in a population seeking osteopathy care: consecutive sample of 611 patients

Background

Life satisfaction is a component of the subjective well-being construct. Research consistently suggests that life satisfaction is associated with enhanced social benefits and improved health outcomes. However, its relationship to musculoskeletal health outcomes is underexplored. This study evaluates the life satisfaction of a patient population presenting with musculoskeletal complaints, and the relationship of life satisfaction with other health demographics and behaviours.

Method

The study used a consecutive sampling design. Patients attending the Victoria University Osteopathy Clinic (Melbourne, Australia) were invited to complete the PROMIS® General Life Satisfaction scale (GLSS) along with questions related to health demographics and behaviours.

Results

The GLSS T-score was not significantly different for gender, being born outside of Australia, speaking English at home, or complaint chronicity.

Conclusions

Life satisfaction did not appear to be related to a range of health and demographic variables in the current musculoskeletal pain cohort. The PROMIS® General Life Satisfaction scale could prove useful to explore the relationship between life satisfaction and treatment outcomes for musculoskeletal complaints.

Determinants of health, health behaviours and demographic profile of patients attending an Australian university student-led osteopathy clinic

Background

Profiles of health professions practice can inform pre-professional education, provide evidence to assist with interprofessional practice, and inform policy development. An understanding of the profile of patients seeking osteopathy care is emerging. Current research suggests that musculoskeletal presentations predominate with approximately one-third of patients presenting with co-morbid diseases. There is little data on these presentations in Australian osteopathy practice. This study aimed to describe the patient demographics, clinical presentations, health behaviours and determinants of health, including health literacy, of those attending for care at an Australian student-led osteopathy clinic.

Methods

A convenience sample design was utilised where consecutive patients presenting for their initial consultation were invited to complete a health information questionnaire during 2016–2017. The questionnaire explored a range of health behaviours and the patient’s health status. Data from the clinical records were also extracted to establish the presenting complaint, duration of the complaint and pertinent demographics. Descriptive statistics were generated for each variable.

Results

Data were available for 1617 patients presenting for their initial consultation. The mean age of patients was 33.7 (±13.1) years with 55% (n = 887) identifying as female. Acute presentations predominated (n = 840, 52%), with presentations affecting the spine being the most common (57.8%). Most patients rated their health status as good to very good (75%). Approximately 7.5% of patients were identified as having low health literacy and 55.9% were currently suffering from one or more co-morbid presentations.

Conclusions

The demographic profile and presenting complaints of patients presenting to a student-led osteopathy clinic are largely consistent with other Australian private practice profiles. The current work also identified co-morbid presentations, and positive and negative health behaviours. Osteopaths may play a role in the management of, or referral for, these presentations where health behaviours require change, or management of co-morbid conditions is beyond the scope of practice. The increasing volume of patient profile literature globally suggests that osteopaths can play a substantial role in the management of musculoskeletal complaints. Further, osteopathy may play a role in screening determinants of health, and engage in multidisciplinary care to ensure those patients with co-morbid conditions or adverse health behaviours are managed appropriately.

Interaction of recommended levels of physical activity and protein intake is associated with greater physical function and lower fat mass in older women: Kuopio Osteoporosis Risk Factor- (OSTPRE) and Fracture-Prevention Study

The aim of the study was to investigate whether the interaction of physical activity (PA) and protein intake is associated with physical function (PF). The women from the Osteoporosis Risk Factor and Fracture Prevention Study (n 610) completed a questionnaire on lifestyle factors and PA and underwent PF and body composition measurements at baseline (BL) and over 3 years of follow-up (3y-FU). PA was categorised according to WHO cut-off PA = 0, 0 < PA < 2·5 and PA ≥ 2·5 h/week. Protein intake was calculated from the 3-d food record at baseline and categorised according to the Nordic Nutrition Recommendations <1·1 and ≥1·1 g/kg body weight (BW). The results showed in univariate ANOVA at the baseline and at the 3-year follow-up, women with high PA ≥ 2·5 h/week and protein intake ≥ 1·1 g/kg BW had higher grip strength adjusted for BMI, higher mean number of chair rises, faster mean walking speed, higher modified mean short physical performance battery score and lower mean fat mass compared with other interaction groups. High PA and protein intake were associated with lower BMI despite significantly higher energy intake. In conclusion, higher PA and protein intake interaction was associated with greater PF and lower fat mass, but the association with relative skeletal muscle index and muscle mass was inconclusive. The present study gives noteworthy information for preventing sarcopenia.

Enhancing the value of accelerometer-assessed physical activity: meaningful visual comparisons of data-driven translational accelerometer metrics

The lack of consensus on meaningful and interpretable physical activity outcomes from accelerometer data hampers comparison across studies. Cut-point analyses are simple to apply and easy to interpret but can lead to results that are not comparable. We propose that the optimal accelerometer metrics for data analysis are not the same as the optimal metrics for translation. Ideally, analytical metrics are precise continuous variables that cover the intensity spectrum, while translational metrics facilitate meaningful, public-health messages and can be described in terms of activities (e.g. brisk walking) or intensity (e.g. moderate-to-vigorous physical activity). Two analytical metrics that capture the volume and intensity of the 24-h activity profile are average acceleration (volume) and intensity gradient (intensity distribution). These allow investigation of independent, additive and interactive associations of volume and intensity of activity with health; however, they are not immediately interpretable. The MX metrics, the acceleration above which the most active X minutes are accumulated, are translational metrics that can be interpreted in terms of indicative activities. Using a range of MX metrics illustrates the intensity gradient and average acceleration (i.e. 24-h activity profile). The M120, M60, M30, M15 and M5 illustrate the most active accumulated minutes of the day, the M¹/_3DAY the most active accumulated 8 h of the day. We demonstrate how radar plots of MX metrics can be used to interpret and translate results from between- and within-group comparisons, provide information on meeting guidelines, assess individual activity profiles relative to percentiles and compare activity profiles between domains and/or time periods.

Chronic noncommunicable diseases multimorbidity and its association with physical activity and television time in a representative Brazilian population

Lifestyle behaviors need to be more explored within the context of chronic noncommunicable disease (NCD) multimorbidity. This study aimed to investigate the association of multimorbidity with physical activity and sedentary behavior in a representative Brazilian population (n = 52,929). A cross-sectional survey (VIGITEL in the Portuguese acronym) was conducted in 2013 in the 27 Brazilian federal units. Multimorbidity is defined as the presence of two or more NCDs, that is, the outcome variable; and physical activity (commuting, domestic chores, leisure, and work domains) and sedentary behavior (television time < 2 hours/day and ≥ 2 hours/day) were the exposure variables. Poisson and multinomial logistic regressions (odds ratio - OR) stratified by age and their respective 95% confidence intervals were used, adopting a significance level of 5%. Among 37,947 adults, the presence of three chronic diseases was less frequent in subjects active in the work domain (OR = 0.60) and more frequent among those with longer daily television time (OR = 1.25). The presence of four diseases was less frequent in subjects active in the commuting (OR = 0.52) and work (OR = 0.42) domains. Among 14,982 older adults, the presence of two, three, and four chronic diseases was consistently more frequent in those with longer daily television time (OR = 1.33; 1.55 and 1.93, respectively). Finally, interactions between total physical activity level and daily television time were statistically significant in the multimorbidity in both age groups. Physical activity and sedentary behavior are associated with multimorbidity and should be considered independent factors for health promotion and for the treatment of patients with multimorbidity.

The Association between First Fractures Sustained during Childhood and Adulthood and Bone Measures in Young Adulthood

OBJECTIVE

To describe the association between fractures sustained at different stages of growth and bone measures in early adulthood.

STUDY DESIGN

Participants (n = 201) in southern Tasmania were at birth at a higher risk of sudden infant death syndrome; they were followed to age 25. Outcomes were areal bone mineral density at the spine, hip, and total body (by dual-energy x-ray absorptiometry) and trabecular and cortical bone measures at the radius and tibia (by high-resolution peripheral quantitative computed tomography). Fractures were self-reported and confirmed by radiographs at 8, 16, and 25 years of age. Multivariable linear regression was used to analyze the association of the occurrence of prepubertal (<9 years of age), pubertal (9-16 years of age), and postpubertal (17-25 years of age) fractures with all bone measures.

RESULTS

Over 25 years, 99 participants had at least 1 fracture. For high-resolution peripheral quantitative computed tomography measures at age 25, prepubertal fractures were negatively associated with cortical and trabecular volumetric bone mineral density and most microarchitecture measures at both the tibia and radius. Prepubertal fractures had a significant association with smaller increase of areal bone mineral density from age 8 to 16 years and at 25 years of age compared with participants with no fractures. Pubertal fractures had no association with any bone measures and postpubertal fractures were only associated with a lower trabecular number at the tibia.

CONCLUSIONS

Prepubertal fractures are negatively associated with areal bone mineral density increases during growth and high-resolution peripheral quantitative computed tomography bone measures in young adulthood. There is little evidence that fractures occurring from age 8 years onward with bone measures in young adulthood, implying that prepubertal fractures may be associated with bone deficits later in life.

Moderate-to-Vigorous Physical Activity Is Associated With Higher Muscle Oxidative Capacity in Older Adults

BACKGROUND

Age-related decline in muscle oxidative capacity reduces muscle function and physical performance, leading to disability and frailty. Whether age-related decline in oxidative capacity is modified by exercise and other lifestyle practices is unclear. Therefore, we tested the hypothesis that physical activity is associated with better oxidative capacity, independent of age.

DESIGN

Cross-sectional study performed in the Baltimore Longitudinal Study of Aging, conducted by the Intramural Research Program (IRP) of the National Institute on Aging (NIA).

SETTING

NIA IRP Clinical Research Unit, Baltimore, MD.

PARTICIPANTS

Participants included 384 adults (54.7% women), aged 22 to 92 years, seen between 2013 and 2017.

MEASUREMENTS

Muscle oxidative capacity was measured in vivo using phosphorous magnetic resonance spectroscopy. We determined the postexercise time constant (τ_PCr ; in seconds) for phosphocreatine (PCr) recovery, with lower values of τ_PCr, (ie, more rapid recovery of PCr levels after exercise) reflecting greater oxidative capacity. Time spent in moderate-to-vigorous physical activity (MVPA) was assessed using wearable accelerometers that participants wore 5.9 ± 0.9 consecutive days in the free-living environment.

RESULTS

In linear regression models, higher τ_PCr was associated with older age (standardized β = .39; P < .001) after adjusting for sex, race, height, and weight. After including MVPA as an independent variable, the standardized regression coefficient of age decreased by 40%, but remained associated with τ_PCr (β_age = .22; P < .001) and had a smaller standardized regression coefficient than MVPA (β_MVPA = -.33; P < .001). After adjusting for health status, education, and smoking history, the standardized regression coefficient for age decreased 12% (β_age = .20; P = .003), while the standardized coefficient for MVPA decreased only 3% (β_MVPA = -.32; P < .001).

CONCLUSION

Study findings suggest that MVPA is strongly associated with muscle oxidative capacity, independent of age, providing mechanistic insights into the health benefits of exercise in older age. J Am Geriatr Soc 67:1695-1699, 2019.

The Association of Vitamin D in Youth and Early Adulthood with Bone Mineral Density and Microarchitecture in Early Adulthood

This study aimed to describe the association of vitamin D status at different stages of growth with bone measures in adolescence and early adulthood. There were 415 participants followed from age 8 to 16, and 201 further followed to age 25. Areal bone mineral density (BMD) at the spine, hip and total body was measured by dual-energy X-ray absorptiometry at ages 16 and 25, and tibial and radial trabecular and cortical bone microarchitecture by high resolution peripheral quantitative computerised tomography at age 25. Serum 25-hydroxyvitamin D (25OHD) concentrations were measured at ages 8, 16 and 25. Multivariable linear regression was used to analyse the association of 25OHD concentrations at three timepoints with bone measures at ages 16 and 25. The proportion of participants with vitamin D deficiency (< 50 nmol/L) was 11%, 43% and 41% at three timepoints, respectively. Serum 25OHD concentrations at age 8 were not significantly associated with any bone measures at age 16 or 25. Serum 25OHD concentrations at age 16 had a significant association with higher BMD at nearly all sites at ages 16 and 25 as well as lower radial porosity and more compact trabecular microarchitecture (higher density, increased number and reduced separation) at both the radius and tibia at age 25. Serum 25OHD concentrations at age 25 were only associated with hip BMD. Higher vitamin D concentrations in adolescence, to a lesser extent at age 25, have beneficial associations with BMD and bone microarchitecture in early adulthood. Optimising vitamin D status particularly during adolescence should be a priority.

Does the intensity of daily walking matter for protecting against the development of a slow gait speed in people with or at high risk of knee osteoarthritis? An observational study

OBJECTIVE

Knee osteoarthritis (OA) is a risk factor for a decline in gait speed. Daily walking reduces the risk of developing slow gait speed and future persistent functional limitation. However, the protective role of walking intensity is unclear. We investigated the association of substituting time spent not walking, with walking at light and moderate-to-vigorous intensities for incident slow gait over 2-years, among people with or at high risk of knee OA.

METHOD

We used baseline and 2-year follow-up data from the Multicenter Osteoarthritis (MOST) study (n = 1731) and the Osteoarthritis Initiative (OAI, n = 1925). Daily walking intensity was objectively assessed using accelerometer-enabled devices, and classified as; not walking (<1 steps/min), very-light (1-49 steps/min), light (50-100 steps/min), and moderate-to-vigorous (>100 steps/min). We defined slow gait during a 20-m walk, as <1 m/s and <1.2 m/s. Isotemporal substitution evaluated time-substitution effects on incident slow gait outcomes at 2-years.

RESULTS

Replacing 20 min/day of not walking with walking at a moderate-to-vigorous intensity, demonstrated small to moderate reductions in the risk of developing a gait speed <1.0 m/s (Relative Risk [95% confidence interval (CI)]; MOST = 0.51 [0.27, 0.98], OAI = 0.21 [0.04, 0.98]), and <1.2 m/s (MOST = 0.73 [0.53, 1.00], OAI = 0.65 [0.36, 1.18]). However, only risk reductions for <1.0 m/s met statistical significance. Replacing not walking with very-light or light intensity walking was not associated with the risk of developing slow gait outcomes.

CONCLUSION

When possible, walking at a moderate-to-vigorous intensity (>100 steps/min) may be best recommended in order to reduce the risk of developing critical slow gait speed among people with, or at high risk of knee OA.

Leisure-time physical activity at moderate and high intensity is associated with parameters of body composition, muscle strength and sarcopenia in aged adults with obesity and metabolic syndrome from the PREDIMED-Plus study

AIMS

We aimed to examine the associations of leisure-time physical activity (PA) and sedentary behavior (SB) with the prevalence of sarcopenia, body composition and muscle strength among older adults having overweight/obesity and metabolic syndrome, from the PREDIMED-Plus trial.

METHODS

Cross-sectional baseline analysis including 1539 men and women (65 ± 5 y). Sarcopenia was defined as low muscle mass (according to FNIH cut-offs) plus low muscle strength (lowest sex-specific tertile for 30-s chair-stand test). We applied multivariable-adjusted Cox regression with robust variance and constant time (given the cross-sectional design) for the associations of self-reported leisure-time PA and SB with sarcopenia; and multivariable-linear regression for the associations with dual-energy X-ray absorptiometry (DXA)-derived bone mass, fat mass, lean mass and lower-limb muscle strength.

RESULTS

Inverse associations were observed between sarcopenia and each hourly increment in total [prevalence ratio 0.81 (95% confidence interval, 0.70, 0.93)], moderate [0.80 (0.66, 0.97)], vigorous [0.51 (0.32, 0.84)], and moderate-vigorous PA (MVPA) [0.74 (0.62, 0.89)]. Incrementing 1-h/day total-PA and MVPA was inversely associated with body-mass-index, waist circumference (WC), fat mass, and positively associated with bone mass and lower-limb muscle strength (all P <.05). One h/day increase in total SB, screen-based SB and TV-viewing was positively associated with body-mass-index, WC and fat mass. Light-PA was not significantly associated with any outcome.

CONCLUSIONS

Total-PA and PA at moderate and high intensities may protect against the prevalence of sarcopenia, have a beneficial role on body composition and prevent loss of muscle strength. SB, particularly TV-viewing, may have detrimental effects on body composition in older adults at high cardiovascular risk.

Familial resemblance in trabecular and cortical volumetric bone mineral density and bone microarchitecture as measured by HRpQCT

To estimate the heritability of bone geometry, volumetric bone mineral density (vBMD) and microarchitecture of trabecular (Tb) and cortical (Ct) bone measured by high resolution peripheral quantitative computerised tomography (HRpQCT) at the distal radius and tibia and to investigate the genetic correlations of these measures. Participants were 177 mother-offspring pairs from 162 families (mothers, mean age (SD) = 52.1 (4.7) years; offspring, 25.6 (0.73) years). Trabecular and cortical bone measures were obtained by HRpQCT. Multivariable linear regression was used to analyse the association of bone measures between mother and offspring. Sequential Oligogenic Linkage Analysis Routines (SOLAR) software was utilised to conduct quantitative genetic analyses. All maternal bone measures were independently associated with the corresponding bone measures in the offspring before and after adjustment for age, sex, weight and height. Heritability estimates ranged from 24% to 67% at the radius and from 42% to 74% at the tibia. The relationship for most bone geometry measures was significantly stronger in mother-son pairs (n = 107) compared with mother-daughter pairs (n = 70) (p < 0.05). In contrast, the heritability for most vBMD and microarchitecture measures were higher in mother-daughter pairs. Bivariate analyses found moderate to strong genetic correlations across all measures between radius and tibia (R_g = 0.49 to 0.93). Genetic factors have an important role in the development of bone geometry, vBMD and microarchitecture. These factors are strongly shared for the radius and tibia but vary by sex implying a role for imprinting.

Power of lower extremities is most important determinant of agility among physically inactive or active adult people

OBJECTIVE

The purpose of this cross-sectional study was to determine the relationships between agility, running speed, jumping height and length, body mass index, self-report pain in back and in lower extremities, personal factors as self-report health and fitness, and leisure time physical activity in physically inactive or active adult people.

METHODS

Altogether, 233 healthy subjects, 149 women (43.0 ± 7.3 years) and 84 men (44.0 ± 7.7 years), participated into study. Outcome measures were described in the International Classification of Functioning, Disability and Health domains.

RESULTS

Multiple regression analysis showed that jumping length explained 24.6% and 15.3% of the variance associated with agility in women and men (adjusted R²  = .246, p < .001; adjusted R²  = .153, p = .001, respectively).

CONCLUSIONS

Jumping length was the main determinant of agility among physically inactive or active women and men. The findings of this study strengthen opinion that the Agility Test for Adults demands also other physical and cognitive characteristics as measured now and their part explaining agility results may be relatively great. We suggest that perception and decision making explain for a great part in agility. It seems that body mass index does not play important role in agility, but physical inactivity can explain or increase the decline of agility. Also, various biological mechanisms in aging process can be linked to the deterioration of capacity of agility.

Force-velocity profiling in older adults: An adequate tool for the management of functional trajectories with aging

INTRODUCTION

The actual mechanisms leading to a reduced muscle power and functional ability in older adults are poorly understood. We investigated the association between different force-velocity (F-V) profiles and impaired muscle power, physical and cognitive function, frailty, and health-related quality of life (HRQoL) in older people.

METHODS

Physical function (habitual gait speed, timed up-and-go test, sit-to-stand and stair-climbing ability), cognitive function, HRQoL and frailty were evaluated in 31 older subjects (70-85 years). The F-V relationship and maximal muscle power (P_max) were assessed in the leg press exercise. The skeletal muscle index (SMI) and fat index, moderate-to-vigorous physical activity (MVPA) and sedentary time were obtained from DXA scans and accelerometry, respectively.

RESULTS

While some subjects showed a force deficit (F_DEF), others presented a velocity deficit (V_DEF), both leading to an impaired muscle power [Effect size (ES) = 1.30-1.44], and to a likely-very likely moderate harmful effect in their physical and cognitive function, HRQoL and frailty levels (except the V_DEF group for cognitive function) [ES = 0.76-1.05]. Leg muscle mass and specific force were similarly associated with force at P_max, while MVPA but not sedentary time was related to fat index, force at P_max, and power values (all p < 0.05). A trend was found for the negative association between fat index and relative P_max (p = 0.075).

CONCLUSION

Older subjects exhibited different mechanisms (force vs. velocity deficits) leading to impaired muscle power. Both deficits were associated with a lower physical function and quality of life, and a higher frailty, whereas only a force deficit was associated with a lower cognitive function. Interventions aimed at reversing age- and/or disuse-related impairments of muscle power might evaluate the specific responsible mechanism and act accordingly.

Correlates of sedentary behaviour among adults with hazardous drinking habits in six low- and middle-income countries

Sedentary behaviour is associated with poor mental health, diabetes and cardiovascular disease, all of which are a concern among hazardous drinkers. Little is known about sedentary behaviour and it's correlates in hazardous drinkers, particularly in low- and middle-income countries. We investigated correlates of sedentary behaviour among community-dwelling adults aged ≥18 years with hazardous drinking patterns in six low- and middle-income countries. Cross-sectional data were analyzed from the World Health Organization's Study on Global Ageing and Adult Health. Hazardous drinking was defined as consuming >7 (females) or >14 (males) standard drinks per week. Associations between time spent sedentary and a range of correlates were examined using multivariable linear and logistic regression. The mean time spent sedentary in 2142 individuals with hazardous drinking patterns (mean age = 45.7 years; 13% female) was 216±135min/day. Nine percent (95%CI=6.1-13.2%) were sedentary for ≥8h per day. Living in an urban setting and unemployment were strong sociodemographic correlates of being sedentary for ≥8h per day. From a health-related perspective, weak grip strength, stroke and disability were associated with increasing time spent sedentary. The current data provides important guidance for future interventions across low- and middle-income countries to assist hazardous drinkers to reduce sedentary behaviour.

Prescribing Physical Activity for the Prevention and Treatment of Osteoporosis in Older Adults

Osteoporosis is an age-related disease, characterised by low bone mineral density (BMD) and compromised bone geometry and microarchitecture, leading to reduced bone strength. Physical activity (PA) has potential as a therapy for osteoporosis, yet different modalities of PA have varying influences on bone health. This review explores current evidence for the benefits of PA, and targeted exercise regimes for the prevention and treatment of osteoporosis in older adults. In particular, the outcomes of interventions involving resistance training, low- and high-impact weight bearing activities, and whole-body vibration therapy are discussed. Finally, we present recommendations for future research that may maximise the potential of exercise in primary and secondary prevention of osteoporosis in the ageing population.

Bone health in Down syndrome

Patients with Down syndrome have a number of risk factors that theoretically could predispose them to osteoporosis, such as early aging, development disorders, reduced physical activity, limited sun exposure, frequent comorbidities and use of drug therapies which could affect bone metabolism. In addition, the bone mass of these people may be affected by their anthropometric and body composition peculiarities. In general terms, studies in adults with Down syndrome reported that these people have lower areal bone mineral density (g/cm²) than the general population. However, most of them have not taken the smaller bone size of people with Down syndrome into account. In fact, when body mineral density is adjusted by bone size and we obtain volumetric body mineral density (g/cm³), the difference between both populations disappears. On the other hand, although people with Down syndrome have risk factor of hypovitaminosis D, the results of studies regarding 25(OH)D in this population are not clear. Likewise, the studies about biochemical bone markers or the prevalence of fractures are not conclusive.