Aggio et al. Respond to “Lessons for Research on Cognitive Aging”

We thank Dr. Belsky (1) for his interest in our study (2), in which we investigated associations between physical activity and cognitive function in young people. He raises several important issues on the role of physical activity as a public health strategy in the prevention of cognitive decline. The issue of “neuroselection,” wherein individuals with better cognitive function are more likely to engage in healthy behaviors such as physical activity and refrain from unhealthy ones such as smoking, is a potential source of bias in observational studies. The alternative hypothesis is that of “neuroprotection,” in which engagement in healthy behaviors is likely to lead to enhanced cognitive development

Validity and reliability of a modified English version of the Physical Activity Questionnaire for Adolescents

Background: Adaptation of physical activity self-report questionnaires is sometimes required to reflect the activity behaviours of diverse populations. The processes used to modify self-report questionnaires though are typically underreported. This two-phased study used a formative approach to investigate the validity and reliability of the Physical Activity Questionnaire for Adolescents (PAQ-A) in English youth. Phase one examined test content and response process validity and subsequently informed a modified version of the PAQ-A. Phase two assessed the validity and reliability of the modified PAQ-A. Methods: In phase one, focus groups (n=5) were conducted with adolescents (n=20) to investigate test content and response processes of the original PAQ-A. Based on evidence gathered in phase one, a modified version of the questionnaire was administered to participants (n=169, 14.5±1.7 years) in phase two. Internal consistency and test-retest reliability were assessed using Cronbach’s alpha and intra-class correlations, respectively. Spearman correlations were used to assess associations between modified PAQ-A scores and accelerometer-derived physical activity, self-reported fitness and physical activity self-efficacy. Results: Phase one revealed that the original PAQ-A was unrepresentative for English youth and that item comprehension varied. Contextual and population/cultural-specific modifications were made to the PAQ-A for use in the subsequent phase. In phase two, modified PAQ-A scores had acceptable internal consistency (α=0.72) and test-retest reliability (ICC=0.78). Modified PAQ-A scores were significantly associated with objectively assessed moderate-to-vigorous physical activity (r=0.39), total physical activity (r=0.42), self-reported fitness (r=0.35), and physical activity self-efficacy (r=0.32) (p≤0.01). Conclusions: The modified PAQ-A had acceptable internal consistency and test-retest reliability. Modified PAQ-A scores displayed weak-to-moderate correlations with objectively measured physical activity, self-reported fitness, and self-efficacy providing evidence of satisfactory criterion and construct validity, respectively. Further testing with more diverse English samples is recommended to provide a more complete assessment of the tool

Sedentary behaviour among elite professional footballers: Health and performance implications

Background: Elite athletes should have little concern about meeting recommended guidelines on physical activity. However, sedentary behaviour is considered a health risk independent of physical activity, and is recognised in public health guidelines advising against prolonged sedentary time. There has been very little research on athletes’ physical activity behaviour outside elite sport. Methods: Given health and performance links, we investigated in-season post-training activity levels in 28 elite professional footballers during the English Premiership season. Players volunteered to wear a triaxial wrist accelerometer for 1 week, removing it only for training and matches. In total, 25 players met the inclusion criteria for analysis. Players recorded on average 632.6 min wear time p/day during the post-training period (SD±52.9) for a mean of 3.8 days (SD±1.5). Results: On average, players recorded 76.2 min p/day (SD±28.8) of moderate or vigorous activity post-training. The majority (79%) of post-training time was spent in sedentary activities (500.6 min per day±59.0). Conclusions: Professional footballers are alarmingly sedentary in their leisure time, and comparatively more so than non-athletic groups of a similar age and older. This raises questions over optimum recovery and performance, as well as long-term health and cardiovascular risk. Worryingly, retirement from elite sport is likely to further imbalance activity and sedentary behaviour. Promoting regular periodic light to moderate leisure time activity could be beneficial. Further research and provision of education and support for players is required in this area

Association between physical activity levels in mid-life with physical activity in old age: a 20-year tracking study in a prospective cohort.

OBJECTIVES: This study aims to examine the tracking and predictability of physical activity in old age from overall physical activity and participation in sport, recreational activity and walking in mid-life. DESIGN: Prospective population-based cohort study. SETTING: British Regional Heart Study participants recruited from primary care centres in the UK in 1978-1980. PARTICIPANTS AND OUTCOME MEASURES: Men (n=3413) self-reported their physical activity at baseline, 12, 16 and 20-year follow-ups and were categorised as inactive or active and having high or low participation in sport, walking and recreational activities. Tracking was assessed using kappa statistics and random effects models. Logistic regression estimated the odds of being active at 20-year follow-up according to physical activity participation in mid-life. RESULTS: Among 3413 men (mean age at baseline 48.6±5.4 years) with complete data, tracking of overall physical activity was moderate (kappa: 0.23-0.26). Tracking was higher for sports participation (kappa: 0.35-0.38) compared with recreational activity (kappa: 0.16-0.24) and walking (kappa: 0.11-0.15). Intraclass correlation coefficients demonstrated similar levels of stability and only marginally weakened after controlling for covariates. Compared with inactive men, being active at baseline was associated with greater odds of being active at 20-year follow-up (OR 2.7, 95% CI 2.4 to 3.2) after adjusting for sociodemographic, health and lifestyle variables. Playing sport in mid-life was more strongly associated with being active at 20-year follow-up than other domains, particularly when sport participation began earlier in life. CONCLUSION: Being physically active in mid-life increases the odds of being active in old age. Promoting physical activity in later life might be best achieved by promoting sport participation earlier in the life course

Effect of major school playground reconstruction on physical activity and sedentary behaviour: Camden active spaces.

BACKGROUND: The physical school environment is a promising setting to increase children's physical activity although robust evidence is sparse. We examined the effects of major playground reconstruction on physical activity and sedentary time in primary schools using a quasi-experimental design (comparison group pre-test/post-test design). METHODS: Five experimental and two control schools from deprived areas of inner city London were recruited at baseline. Main outcome was physical activity and sedentary time measured from objective monitoring (Actigraph accelerometer) at one year follow up. Pupils' impressions of the new playground were qualitatively assessed post construction. RESULTS: A total of 347 pupils (mean age = 8 years, 55% boys; 36% Caucasian) were recruited into the study at baseline; 303 provided valid baseline Actigraph data. Of those, 231 (76%) completed follow-up (n = 169 intervention; n = 62 control) and 77.4% of the sample recorded at least 4 days of Actigraph wear. In mixed models adjusted for age, sex, ethnicity, ratio activity or sedentary/wear time at baseline, wear time at follow up, and school, no differences were observed in total moderate - vigorous activity (B = -1.4, 95% CI, -7.1, 4.2 min/d), light activity (B = 4.1, 95% CI, -17.9, 26.1), or sedentary time (B = -3.8, 95% CI, -29.2, 21.6 min/d) between groups. There were significant age interactions for sedentary (p = 0.002) and light intensity physical activity (p = 0.008). We observed significant reductions in total sedentary (-28.0, 95% CI, -1.9, -54.1 min/d, p = 0.037) and increases in total light intensity activity (24.6, 95% CI, 0.3, 48.9 min/d, p = 0.047) for children aged under 9 yrs. old in the intervention. CONCLUSION: Major playground reconstruction had limited effects on physical activity, but reduced sedentary time was observed in younger children. Qualitative data suggested that the children enjoyed the new playgrounds and experienced a perceived positive change in well-being and social interactions

Trajectories of physical activity from midlife to old age and associations with subsequent cardiovascular disease and all-cause mortality.

INTRODUCTION: It is well established that physical activity (PA) protects against mortality and morbidity, but how long-term patterns of PA are associated with mortality and cardiovascular disease (CVD) remains unclear. METHODS: 3231 men recruited to the British Regional Heart Study, a prospective cohort study, reported usual PA levels at baseline in 1978-1980 (aged 40-59 years) and at 12-year, 16-year and 20-year follow ups. Twenty-year trajectories of PA, spanning from 1978/1980 to 2000, were identified using group-based trajectory modelling. Men were subsequently followed up until 30 June 2016 for mortality through National Health Service central registers and for non-fatal CVD events through primary and secondary care records. Data analyses were conducted in 2019. RESULTS: Three PA trajectories were identified: low/decreasing (22.7%), light/stable (51.0%) and moderate/increasing (26.3%). Over a median follow-up of 16.4 years, there were 1735 deaths. Compared with the low/decreasing group, membership of the light/stable (HR 0.83, 95% CI 0.74 to 0.94) and moderate/increasing (HR 0.76, 95% CI 0.66 to 0.88) groups was associated with a lower risk of all-cause mortality. Similar associations were observed for CVD mortality, major coronary heart disease and all CVD events. Associations were only partially explained by a range of confounders. Sensitivity analyses suggested that survival benefits were largely driven by most recent/current PA. CONCLUSIONS: A dose-response relationship was observed, with higher levels of PA from midlife to old age associated with additional benefits. However, even fairly modest and sustained PA was protective and may be more achievable for the most inactive

Association Between 20-Year Trajectories of Nonoccupational Physical Activity From Midlife to Old Age and Biomarkers of Cardiovascular Disease: A 20-Year Longitudinal Study of British Men

The trajectories of physical activity (PA) from midlife into old age and their associations with established and novel cardiovascular disease (CVD) risk factors in later life remain unclear. This study examined associations between 20-year non-occupational PA trajectories and a range of CVD biomarkers at 60-79 years. 3,331 men (mean baseline age = 50.2 ± 5.8 years) recruited in 1978-80 were followed up after 12, 16 and 20 years, reporting habitual non-occupational PA at each wave. At the 20-year follow up, surviving men attended a physical examination and provided a fasting blood sample. Group-based trajectory modelling was used to identify trajectories. Adjusted regression analyses examined the association between trajectory group membership and several cardiometabolic, cardiac and inflammatory markers at follow up. Three distinct 20-year trajectories were identified: low decreasing (21.3%), light stable (51.8%) and moderate increasing (27.0%). Compared to the low decreasing group, membership of the light stable and moderate increasing trajectory groups was associated with a more favorable cardiometabolic profile, lower levels of inflammation and endothelial dysfunction. Although following a moderate increasing PA trajectory was most favorable, more modest but sustained doses of PA into old age may be sufficient to lower CVD risk

Twenty-Year Trajectories of Physical Activity Types from Midlife to Old Age.

PURPOSE: Correlates of physical activity (PA) vary according to type. However, predictors of long-term patterns of PA types into old age are unknown. This study aimed to identify 20-yr trajectories of PA types into old age and their predictors. METHODS: Seven thousand seven hundred thirty-five men (age, 40-59 yr) recruited from UK towns in 1978 to 1980 were followed up after 12, 16, and 20 yr. Men reported participation in sport/exercise, recreational activity and walking, health status, lifestyle behaviors and socio-demographic characteristics. Group-based trajectory modeling identified the trajectories of PA types and associations with time-stable and time-varying covariates. RESULTS: Men with ≥3 measures of sport/exercise (n = 5116), recreational activity (n = 5085) and walking (n = 5106) respectively were included in analyses. Three trajectory groups were identified for sport/exercise, four for recreational activity and three for walking. Poor health, obesity and smoking were associated with reduced odds of following a more favorable trajectory for all PA types. A range of socioeconomic, regional and lifestyle factors were also associated with PA trajectories but the magnitude and direction were specific to PA type. For example, men with manual occupations were less likely to follow a favorable sport/exercise trajectory but more likely to follow an increasing walking trajectory compared to men with nonmanual occupations. Retirement was associated with increased PA but this was largely due to increased sport/exercise participation. CONCLUSIONS: Physical activity trajectories from middle to old age vary by activity type. The predictors of these trajectories and effects of major life events, such as retirement, are also specific to the type of PA

Tracking of sport and exercise types from midlife to old age: a 20-year cohort study of British men.

Background: Previous physical activity (PA) tracking studies have examined the stability of overall PA and/or PA types, but few have investigated how specific types of sport/exercise track over the life course. The aim of this study was to determine how specific sports/exercises in midlife track and predict future sport/exercise and PA in men transitioning to old age. Methods: Seven thousand seven hundred thirty-five men (aged 40-59 years) recruited in 1978-80 were followed up after 12, 16 and 20 years. At each wave men self-reported participation in sport/exercise. Frequent sport/exercise participants (> 1/month) reported the types of sport/exercise they engaged in. Men also reported total PA, health status, lifestyle behaviours and socio-demographic characteristics. Stability of each sport/exercise was assessed using kappa statistics and intraclass correlation coefficients. Logistic regression estimated the odds of participating in sport/exercise and being active at 20-year follow up according to specific types of sport/exercise in midlife. Results: Three thousand three hundred eighty-four men with complete data at all waves were included in analyses. Tracking of specific sports/exercises ranged from fair to substantial, with golf being the most common and most stable. Bowls was the most frequently adopted. Odds of participating in sport/exercise and being active in old age varied according to sport/exercise types in midlife. Golf and bowls in midlife were the strongest predictors of sport/exercise participation in old age. Golf, cricket and running/jogging in midlife were among the strongest predictors of being active in old age. Compared to participating in just one sport/exercise in midlife, sampling multiple sports/exercises was more strongly associated with sport/exercise participation and being active in old age. Conclusion: The stability of sport/exercise participation from midlife to old age varies by type. Specific sports/exercises in midlife may be more likely to predict future PA than others. However, participating in a range of sports/exercises may be optimal for preserving PA into old age

Effects of reallocating time in different activity intensities on health and fitness: a cross sectional study

BACKGROUND: The effects of replacing time in specific activity categories for other categories (e.g. replacing sedentary time with light activity) on health and fitness are not well known. This study used isotemporal substitution to investigate the effects of substituting activity categories in an equal time exchange fashion on health and fitness in young people. METHODS: Participants were drawn from schools in Camden, London (n = 353, mean age 9.3 ± 2.3 years). Time sedentary, in light and in moderate-to-vigorous activity (MVPA) was measured via accelerometry. The effects of substituting time in activity categories (sedentary, light and MVPA) with equivalent time in another category on health and fitness were examined using isotemporal substitution. RESULTS: In single and partition models, MVPA was favourably associated with body fat %, horizontal jump distance and flexibility. Time sedentary and in light activity were not associated with health and fitness outcomes in these models. In substitution models, replacing one hour of sedentary time with MVPA was favourably associated with body fat % (B = -4.187; 95% confidence interval (CI), -7.233, -1.142), horizontal jump distance (B = 16.093; 95% CI, 7.476, 24.710) and flexibility (B = 4.783; 95% CI, 1.910, 7.656). Replacing time in light activity with MVPA induced similar benefits but there were null effects for replacing sedentary with light intensity. CONCLUSION: Substituting time sedentary and in light activity with MVPA was associated with favourable health and fitness. Time in sedentary behaviour may only be detrimental to health and fitness when it replaces time in MVPA in young people