IntroductionUnderstanding 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.MethodsPA 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.ResultsOlder 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.ConclusionTo 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.

PurposeCardiorespiratory fitness (CRF) is regarded a clinical vital sign, and accurate reference values for all age groups are essential. Little data exist on CRF and cardiorespiratory function in older adults. The aim of this study was to provide normative values for CRF and cardiorespiratory function in older adults, including people with history of cardiovascular diseases (CVD).MethodsIn total, 1537 (769 women) participants age 70 to 77 yr underwent clinical examinations and cardiopulmonary exercise tests. Peak oxygen uptake (V˙O2peak), ventilation (V˙Epeak), expiration of carbon dioxide (VV˙CO2peak), breathing frequency (BFpeak), tidal volume (VTpeak), oxygen pulse (O2 pulsepeak), ventilatory efficiency (EqV˙O2peak and EqV˙CO2peak), and 1-min HR recovery were assessed.ResultsMen compared with women had higher V˙O2peak (31.3 ± 6.7 vs 26.2 ± 5.0 mL·min−1·kg−1), BFpeak (41.8 ± 8.0 vs 39.7 ± 7.1 breaths per minute), VTpeak (2.3 ± 0.5 vs 1.6 ± 0.3), O2 pulsepeak (16.4 ± 3.2 vs 11.3 ± 2.0), V˙CO2peak (2.9 ± 0.2 and 1.9 ± 0.1 L·min−1), V˙Epeak (96.2 ± 21.7 vs 61.1 ± 21.6 L·min−1), EqV˙O2peak (38.0 ± 6.9 vs 35.1 ± 5.6), and EqV˙CO2peak (33.5 ± 5.7 vs 31.9 ± 4.5). Women and men with CVD had lower V˙O2peak (14% and 19%), peak HR (5% and 6%), V˙Epeak (8% and 10%), VTpeak (7% and 4%), and lower EqV˙CO2peak (4% and 6%) compared with their healthy counterparts, respectively. Compared with healthy women and men, 1-min HR recovery was 12% and 16% lower for women and men with CVD.ConclusionsThis study represents the largest reference material on directly measured CRF and cardiorespiratory function in older men and women, with and without CVD. This novel information will help researchers and clinicians to interpret data form cardiopulmonary testing in older adults.

High age-specific CRF fully attenuates the adverse effect of prolonged sedentary time on CV-RF clustering, independent of meeting the PA consensus recommendation in older adults.

BackgroundPublic health initiatives world-wide recommend increasing physical activity (PA) to improve health. However, the dose and the intensity of PA producing the most benefit are still debated. Accurate assessment of PA is necessary in order to 1) investigate the dose–response relationship between PA and health, 2) shape the most beneficial public health initiatives and 3) test the effectiveness of such initiatives. Actigraph accelerometer is widely used to objectively assess PA, and the raw data is given in counts per unit time. Count-thresholds for low, moderate and vigorous PA are mostly based on absolute intensity. This leads to largely inadequate PA intensity assessment in a large proportion of the elderly, who due to their declining maximal oxygen uptake (VO2max) cannot reach the moderate/vigorous intensity as defined in absolute terms. To resolve this issue, here we report relative Actigraph intensity-thresholds for the elderly.MethodsSubmaximal-oxygen-uptake, VO2max and maximal heart rate (HRmax) were measured in 111 70–77 year olds, while wearing an Actigraph-GT3X+. Relationship between VO2max percentage (%), counts-per-minute (CPM) and gender (for both the vertical-axis (VA) and vector-magnitude (VM)) and VO2max% and HRmax% was established using a mixed-regression-model. VM-and VA-models were tested against each other to see which model predicts intensity of PA better.ResultsVO2max and gender significantly affected number of CPM at different PA intensities (p < 0.05). Therefore, intensity-thresholds were created for both men and women of ranging VO2max values (low, medium, high). VM-model was found to be a better predictor of PA-intensity than VA-model (p < 0.05). Established thresholds for moderate intensity (46−63 % of VO2max) ranged from 669–3367 and 834–4048 CPM and vigorous intensity (64−90 % of VO2max) from 1625–4868 and 2012-5423CPM, for women and men, respectively. Lastly, we used this evidence to derive a formula that predicts customized relative intensity of PA (either VO2max% or HRmax%) using counts-per-minute values as input.ConclusionIntensity-thresholds depend on VO2max, gender and Actigraph-axis. PA intensity-thresholds that take all these factors into account allow for more accurate relative intensity PA assessment in the elderly and will be useful in future PA research.Trial registration(ClinicalTrials.gov Identifier: NCT02017847, registered 17. December 2013)

The aim of this study was to identify how demographics, physical activity (PA) history, and environmental and biological correlates are associated with objectively measured PA among older adults. PA was assessed objectively in 850 older adults (70–77 years, 48% females) using the ActiGraph GT3X+ activity monitor. Hierarchical multiple regression analysis was used to identify important PA correlates. The included correlates explained 27.0% of the variance in older adult’s PA. Cardiorespiratory fitness (CRF), gender, and season were the most important correlates, explaining 10.1%, 3.9%, and 2.7% of the variance, respectively. PA was positively associated with CRF, females were more physically active than males, and PA increased in warmer months compared with colder months. This is, to our knowledge, the largest study of PA correlates in older adults that has combined objectively measured PA and CRF. Our findings provide new knowledge about how different correlates are associated with PA.