Tracking of Cardiorespiratory Fitness from Childhood to Mid-adulthood.

High cardiorespiratory fitness (CRF) in adulthood is important for survival from major chronic diseases and preserving good health. We examined how childhood CRF tracks, or persists, into adulthood. Among a cohort of 748 school children followed over 34 years, we found child CRF correlated with young- (r = 0.30) and mid-adulthood (r = 0.16) CRF.

The Influence of Dietary Counseling Over 20 Years on Tracking of Non-High-Density Lipoprotein Cholesterol from Infancy to Young Adulthood.

This 26-year study found that non-high-density lipoprotein cholesterol (non-HDL-C) levels tracked from infancy to young adulthood suggesting early-life non-HDL-C could predict future levels. However, infancy-onset dietary counseling reduced the odds of maintaining at-risk non-HDL-C, highlighting the potential importance of early interventions in preventing cardiovascular risk associated with high pediatric non-HDL-C.

Tracking of apolipoprotein B levels measured in childhood and adolescence: systematic review and meta-analysis.

To quantify the tracking of apolipoprotein B (apoB) levels from childhood and adolescence and compare the tracking of apoB with low-density lipoprotein (LDL) cholesterol, a systematic search of MEDLINE, Embase, Web of Science, and Google Scholar was performed in October 2023 (PROSPERO protocol: CRD42022298663). Cohort studies that measured tracking of apoB from childhood/adolescence (< 19 years) with a minimum follow-up of 1 year, using tracking estimates such as correlation coefficients or tracking coefficients, were eligible. Pooled correlations were estimated using random-effects meta-analysis. Risk of bias was assessed with a review-specific tool. Ten studies of eight unique cohorts involving 4677 participants met the inclusion criteria. Tracking of apoB was observed (pooled r = 0.63; 95% confidence interval [CI] = 0.53-0.71; I2 = 96%) with no significant sources of heterogeneity identified. Data from five cohorts with tracking data for both lipids showed the degree of tracking was similar for apoB (pooled r = 0.59; 95% CI = 0.55-0.63) and LDL cholesterol (pooled r = 0.58; 95% CI = 0.47-0.68). Study risk of bias was moderate, mostly due to attrition and insufficient reporting. CONCLUSION: ApoB levels track strongly from childhood, but do not surpass LDL cholesterol in this regard. While there is strong evidence that apoB is more effective at predicting ASCVD risk than LDL cholesterol in adults, there is currently insufficient evidence to support its increased utility in pediatric settings. This also applies to tracking data, where more comprehensive data are required. WHAT IS KNOWN: • Apolipoprotein B is a known cause of atherosclerotic cardiovascular disease. • Apolipoprotein B levels are not typically measured in pediatric settings, where low-density lipoprotein cholesterol remains the primary lipid screening measure. WHAT IS NEW: • This meta-analysis of 10 studies showed apolipoprotein B levels tracked strongly from childhood but did not exceed low-density lipoprotein cholesterol in this regard. • More comprehensive tracking data are needed to provide sufficient evidence for increased utility of apolipoprotein B in pediatric settings.

Types of leisure-time physical activity participation in childhood and adolescence, and physical activity behaviours and health outcomes in adulthood: a systematic review.

BACKGROUND: Youth leisure-time physical activity participation benefits physical activity habits and health outcomes later in life. However, it is unknown if certain types of leisure-time physical activity contribute to these benefits in different ways; this knowledge could enhance public health efforts. This systematic review aimed to synthesise evidence of the longitudinal associations between childhood and adolescent leisure-time physical activity on adulthood physical activity behaviours and health outcomes. METHODS: A systematic search of the literature was conducted across five databases from inception to July 2022. English, peer-reviewed observational studies with a minimum of two timepoints of data collection were eligible for inclusion. We included studies that investigated the association between participation in leisure-time physical activity types in children and adolescents (i.e., 5-18 years), and physical activity, mental health, or cardiovascular outcomes in adulthood (i.e., ≥ 18 years). RESULTS: Fourteen studies were included in the review, totalling 34,388 observations across five countries. Running in adolescence was associated with increased adulthood physical activity in both sexes, while sports involvement was associated with an increase in physical activity in males only. Adolescent team sports participation was associated with reduced odds of early adulthood depression, with varying findings for anxiety disorders. There was preliminary evidence of minimum threshold requirements for participation in certain activities before associations with future physical activity or health outcome benefits were observed. CONCLUSIONS: Preliminary findings suggest that the lifelong behavioural and health benefits of adolescent participation in leisure-time physical activity appear to be related to the type of activity undertaken, with potential differences between sexes. With the rarity of longitudinal studies spanning from childhood into adulthood, these findings provide important insights for public health strategies to optimise lifelong health and physical activity participation. PROSPERO REGISTRATION: CRD42022347792.

Cardiorespiratory fitness is a strong and consistent predictor of morbidity and mortality among adults: an overview of meta-analyses representing over 20.9 million observations from 199 unique cohort studies.

OBJECTIVE: To examine and summarise evidence from meta-analyses of cohort studies that evaluated the predictive associations between baseline cardiorespiratory fitness (CRF) and health outcomes among adults. DESIGN: Overview of systematic reviews. DATA SOURCE: Five bibliographic databases were searched from January 2002 to March 2024. RESULTS: From the 9062 papers identified, we included 26 systematic reviews. We found eight meta-analyses that described five unique mortality outcomes among general populations. CRF had the largest risk reduction for all-cause mortality when comparing high versus low CRF (HR=0.47; 95% CI 0.39 to 0.56). A dose-response relationship for every 1-metabolic equivalent of task (MET) higher level of CRF was associated with a 11%-17% reduction in all-cause mortality (HR=0.89; 95% CI 0.86 to 0.92, and HR=0.83; 95% CI 0.78 to 0.88). For incident outcomes, nine meta-analyses described 12 unique outcomes. CRF was associated with the largest risk reduction in incident heart failure when comparing high versus low CRF (HR=0.31; 95% CI 0.19 to 0.49). A dose-response relationship for every 1-MET higher level of CRF was associated with a 18% reduction in heart failure (HR=0.82; 95% CI 0.79 to 0.84). Among those living with chronic conditions, nine meta-analyses described four unique outcomes in nine patient groups. CRF was associated with the largest risk reduction for cardiovascular mortality among those living with cardiovascular disease when comparing high versus low CRF (HR=0.27; 95% CI 0.16 to 0.48). The certainty of the evidence across all studies ranged from very low-to-moderate according to Grading of Recommendations, Assessment, Development and Evaluations. CONCLUSION: We found consistent evidence that high CRF is strongly associated with lower risk for a variety of mortality and incident chronic conditions in general and clinical populations.

Tracking handgrip strength asymmetry from childhood to mid-life.

AIM: Determine if asymmetric handgrip strength exists in childhood and adulthood and quantify the degree of tracking of handgrip strength asymmetry over time. METHODS: Participants from the Childhood Determinants of Adult Health Study had their right and left handgrip strength measured using handgrip dynamometry in childhood (1985: 9-15 y), young adulthood (2004-06: 26-36 y) and/or mid-adulthood (2014-19: 36-49 y). Handgrip strength asymmetry was calculated as: strongest handgrip strength/strongest handgrip strength on the other hand. Participants were categorised based on the degree of their asymmetry (0.0%-10.0%, 10.1%-20.0%, 20.1%-30.0%, >30.0%). Tracking was quantified using Spearman's correlations and log binomial regression. RESULTS: Handgrip strength asymmetry was present in childhood and adulthood (>30.0% asymmetry: childhood = 6%, young adulthood = 3%, mid-adulthood = 4%). Handgrip strength asymmetry did not track between childhood and young- (r = 0.06, 95% CI = -0.02, 0.12) and mid-adulthood (r = 0.01, 95% CI = -0.09, 0.10). Tracking was more apparent between young- and mid-adulthood (r = 0.16, 95% CI = 0.09, 0.22). Participants with >30.0% asymmetry were at greater risk to maintain this status between childhood and young- (RR = 3.53, 95% CI = 1.15, 10.87) and mid-adulthood (RR = 2.14, 95% CI = 0.45, 10.20). CONCLUSION: Although handgrip strength asymmetry tracked relatively poorly, asymmetric handgrip strength was apparent in children and adults. Handgrip strength asymmetry does not exclusively affect older adults and should be considered in protocols to better understand its role across the life course.

Muscular strength measured across the life-course and the metabolic syndrome.

BACKGROUND AND AIMS: Low muscular strength associates with the metabolic syndrome (MetS). However, how muscular strength measured at different life stages contribute to the development of MetS is unknown. This study compared the contribution of muscular strength measured in youth, young- and mid-adulthood with MetS in midlife. METHODS AND RESULTS: Prospective longitudinal study of 267 Childhood Determinants of Adult Health Study participants who between 1985 and 2019 had measures of muscular strength (dominant grip strength) at three life stages (youth = 9-15 years, young adulthood = 26-36 years, mid-adulthood = 36-49 years) and had their MetS status assessed in mid-adulthood. Bayesian relevant life-course exposure models quantified associations between muscular strength at each life stage with MetS and estimated the maximum accumulated effect of lifelong muscular strength. The contribution of muscular strength at each life stage with MetS was equal (youth = 38%, young adulthood = 28%, mid-adulthood = 34%). A one standard deviation increase in cumulative muscular strength was associated with 46% reduced odds of MetS. Of all MetS components, muscular strength was most strongly negatively associated with high waist circumference. CONCLUSION: A life-course approach demonstrated reduced odds of MetS in midlife was associated with cumulatively high muscular strength since youth. This supports efforts to promote physical fitness throughout life.

Factors associated with muscular fitness phenotypes in Australian children: A cross-sectional study.

To help inform strategies aimed at increasing muscular fitness levels, we examined factors associated with childhood muscular fitness (strength and power) that preceded the recently observed secular decline. Data were available from a nationally representative sample of Australian children aged 7-15 years in 1985 (n = 8469). Muscular fitness measures included strength (right and left grip, shoulder extension and flexion, and leg strength) and power (standing long jump distance). Anthropometric (adiposity, fat-free mass), cardiorespiratory fitness (CRF), flexibility, speed capability, physical activity (individual and parental), dietary quality and intake (fruit, vegetable, protein) and sociodemographic (area-level socioeconomic status (SES), school type) data were available. Statistical analyses included sex-stratified linear regression. Of all examined factors, measures of adiposity, fat-free mass, CRF, flexibility and speed capability were associated with muscular fitness at levels that met Cohen's threshold for important effects (r-squared = 0.02 to 0.28). These findings highlight the multifactorial relationship between muscular fitness and its determinants. Collectively, these factors were powerful in explaining muscular strength (females: r-squared = 0.32; males: r-squared = 0.41) and muscular power (females: r-squared = 0.36; males: r-squared = 0.42). These findings highlight modifiable and environmental factors that could be targeted to increase childhood muscular fitness.

The association between muscular power from childhood to adulthood and adult measures of glucose homeostasis.

This study aimed to assess whether the longitudinal association between childhood muscular fitness and adult measures of glucose homeostasis persist despite changes in muscular fitness across the life course. This prospective longitudinal study included 586 participants who had their muscular power (standing long jump distance), cardiorespiratory fitness (CRF), and waist circumference measured as children (aged 9, 12, 15 years) and again 20 years later as adults. In adulthood, these participants also provided a fasting blood sample which was tested for glucose and insulin. Glucose homeostasis measures including insulin resistance (HOMA2-IR) and beta cell function (HOMA2-ß) were estimated. Child and adult muscular power levels were separated into thirds, and tracking groups (persistently low, decreasing, persistently moderate, increasing, and persistently high) were created. Sex-stratified multivariable linear regression models were used to examine the association between muscular power tracking groups and adult measures of glucose homeostasis. Compared with males with persistently high muscular power, males with increasing and persistently low muscular power had higher fasting insulin (increasing: ß = 1.12 mU/L, P = .04; persistently low: ß = 2.12 mU/L, P = .001) and HOMA2-ß (increasing: ß = 8.50%, P = .03; persistently low: ß = 11.27%, P = .01) independent of CRF and males with persistently low muscular power had greater fasting insulin (ß = 1.22 mU/L, P = .02) and HOMA2-IR (ß = 0.14, P = .02) independent of waist circumference. Non-significant associations were present for females. For males, maintaining persistently high muscular power between childhood and adulthood could lead to a healthier adult glucose homeostasis profile.

The great leap backward: changes in the jumping performance of Australian children aged 11-12-years between 1985 and 2015.

Previous data have indicated relative stability over time of paediatric jumping performance, but few data exist since the early 2000s. This study quantified the 30-year secular changes in jumping performance of Australian children aged 11-12-years using data from the Australian Schools Health and Fitness Survey (1985, n = 1967) and Growing Up in Australia's Child Health CheckPoint (2015, n = 1765). Both cohorts measured jumping performance (standing long jump distance), anthropometric and demographic data. Secular changes in jumping performance means and quantiles were examined using multivariable linear and quantile regression. Between 1985 and 2015, jumping performance declined by 16.4 cm or by 11.2% (standardised change 0.66 SD, 95%CI 0.60 to 0.73). Adjustment for body mass reduced the effect by 32%, although the decline remained (absolute change - 11.1 cm, 95%CI -12.5 to -9.7; percent change 7.7%, 95%CI 6.7 to 8.6; standardised change 0.51 SD, 95%CI 0.44 to 0.57). This decline was evident across all quantiles. The jumping performance of Australian children aged 11-12-years has declined between 1985 and 2015, with body mass changes accounting for only part of the decline. Efforts should continue to promote paediatric muscular fitness, reduce adiposity, and aim to reverse this decline in jumping performance.

Predictive utility of childhood anthropometric measures on adult glucose homeostasis measures: a 20-year cohort study.

BACKGROUND/OBJECTIVES: Childhood body mass index (BMI) predicts adult glucose homeostasis measures and type 2 diabetes mellitus, but little is known about the predictive utility of other anthropometric measures in childhood. We aimed to identify the anthropometric measure in childhood that best predicts adult glucose homeostasis measures and examine if the combination of additional anthropometric measures further improves predictive utility. METHODS: A 20-year follow-up of children participating in the Childhood Determinants of Adult Health Study (n = 2345, aged 7-15 years at baseline). Baseline anthropometric measures were waist circumference (WC), WC adjusted for height, weight adjusted for height, hip circumference, waist-hip-ratio, waist-height-ratio, BMI, conicity index, abdominal volume index (AVI), body adiposity index, and a body shape index. Fasting glucose and insulin levels measured at follow-up were used to define insulin resistance (HOMA2-IR), low beta-cell function (HOMA2-ß), high fasting insulin, and impaired fasting glucose (IFG). RESULTS: All child anthropometric measures were significantly associated with HOMA2-IR, HOMA2-ß, and high fasting insulin (relative risk = 1.12-1.55), but not IFG. AVI had the largest area under receiver-operating curve (AUC) in predicting adult HOMA2-IR (AUC, 95% confidence interval: 0.610, 0.584-0.637), HOMA2-ß (0.615, 0.588-0.642) and high fasting insulin (0.613, 0.587-0.639). Combining each additional anthropometric measure with AVI did not appreciably increase predictive utility (an increase of 0.001-0.002 in AUC, p > 0.05 for all). CONCLUSIONS: Anthropometric measures from a single time-point in childhood are associated with insulin-related outcomes 20-year later in adulthood. However, overall predictive utility was low and was not substantially enhanced by combining multiple different child anthropometric measures.

Blood Pressure at Different Life Stages Over the Early Life Course and Intima-Media Thickness.

Importance: Although cardiovascular disease (CVD) begins in early life, the extent to which blood pressure (BP) at different life stages contributes to CVD is unclear. Objective: To determine the relative contribution of BP at different life stages across the early-life course from infancy to young adulthood with carotid intima-media thickness (IMT). Design, setting, and participants: The analyses were performed in 2022 using data gathered from July 1989 through January 2018 within the Special Turku Coronary Risk Factor Intervention Project, a randomized, infancy-onset cohort of 534 participants coupled with annual BP (from age 7 months to 20 years), biennial IMT measurements (from ages 13 to 19 years), who were followed up with again at age 26 years. Exposures: BP measured from infancy (aged 7 to 13 months), preschool (2 to 5 years), childhood (6 to 12 years), adolescence (13 to 17 years), and young adulthood (18 to 26 years). Main outcomes and measures: Primary outcomes were carotid IMT measured in young adulthood at age 26 years. Bayesian relevant life-course exposure models assessed the relative contribution of BP at each life stage. Results: Systolic BP at each life stage contributed to the association with young adulthood carotid IMT (infancy: relative weight, 25.3%; 95% credible interval [CrI], 3.6-45.8; preschool childhood: relative weight, 27.0%; 95% CrI, 3.3-57.1; childhood: relative weight, 18.0%; 95% CrI, 0.5-40.0; adolescence: relative weight, 13.5%; 95% CrI, 0.4-37.1; and young adulthood: relative weight, 16.2%; 95% CrI, 1.6-46.1). A 1-SD (at single life-stage) higher systolic BP accumulated across the life course was associated with a higher carotid IMT (0.02 mm; 95% CrI, 0.01-0.03). The findings for carotid IMT were replicated in the Cardiovascular Risk in Young Finns Study that assessed systolic BP from childhood and carotid IMT in adulthood (33 to 45 years). Conclusion and relevance: In this cohort study, a life-course approach indicated that accumulation of risk exposure to BP levels at all life stages contributed to adulthood carotid IMT. Of those, the contribution attributed to each observed life stage was approximately equal. These results support prevention efforts that achieve and maintain normal BP levels across the life course, starting in infancy.

Tracking of serum lipid levels from childhood to adulthood: Systematic review and meta-analysis.

BACKGROUND AND AIMS: The utility of lipid screening in pediatric settings for preventing adult atherosclerotic cardiovascular diseases partly depends on the lifelong tracking of lipid levels. This systematic review aimed to quantify the tracking of lipid levels from childhood and adolescence to adulthood. METHODS: We systematically searched MEDLINE, Embase, Web of Science, and Google Scholar in March 2022. The protocol was registered with the International Prospective Register of Systematic Reviews (PROSPERO; ID: CRD42020208859). We included cohort studies that measured tracking of lipids from childhood or adolescence (<18 years) to adulthood (≥18) with correlation or tracking coefficients. We estimated pooled correlation and tracking coefficients using random-effects meta-analysis. Risk of bias was assessed with a review-specific tool. RESULTS: Thirty-three studies of 19 cohorts (11,020 participants) were included. The degree of tracking from childhood and adolescence to adulthood differed among lipids. Tracking was observed for low-density lipoprotein cholesterol (pooled r = 0.55-0.65), total cholesterol (pooled r = 0.51-0.65), high-density lipoprotein cholesterol (pooled r = 0.46-0.57), and triglycerides (pooled r = 0.32-0.40). Only one study included tracking of non-high-density lipoprotein cholesterol (r = 0.42-0.59). Substantial heterogeneity was observed. Study risk of bias was moderate, mostly due to insufficient reporting and singular measurements at baseline and follow-up. CONCLUSIONS: Early-life lipid measurements are important for predicting adult levels. However, further research is needed to understand the tracking of non-high-density lipoprotein cholesterol and the stability of risk classification over time, which may further inform pediatric lipid screening and assessment strategies.

Prevalence and Trends of Handgrip Strength Asymmetry in the United States.

Background: Strength asymmetries are a type of muscle function impairment that is associated with several health conditions. However, the prevalence of these asymmetries among adults from the United States remains unknown. We sought to estimate the prevalence and trends of handgrip strength (HGS) asymmetry in American adults. Methods: The unweighted analytic sample included 23,056 persons aged at least 50-years with information on HGS for both hands from the 2006-2016 waves of the Health and Retirement Study. A handgrip dynamometer measured HGS, with the highest recorded values for each hand used to calculate asymmetry. Persons were categorized into the following asymmetry severity categories: (1) >10%, (2) >20.0%, and (3) >30.0%. Survey weights were used to generate nationally-representative asymmetry estimates. Results: Overall, there were no statistically significant trends in HGS asymmetry categories over time. The prevalence of HGS asymmetry in the 2014-2016 wave was 53.4% (CI: 52.2-54.4), 26.0% (CI: 25.0-26.9), and 11.7% (CI: 10.9-12.3) for asymmetry at >10%, >20%, and >30%, respectively. HGS asymmetry was generally higher in older Americans compared to middle-aged adults at each wave. In the 2014-2016 wave, >30% asymmetry prevalence was 13.7% (CI: 12.7-14.6) in females and 9.3% (CI: 8.4-10.2) in males. Some differences in asymmetry prevalence by race and ethnicity were observed. Conclusions: The prevalence of asymmetry was generally high, especially in women and older adults. Ongoing surveillance of strength asymmetry will help monitor trends in muscle dysfunction, guide screening for disablement, identify subpopulations at risk for asymmetry, and inform relevant interventions.

Association Between Risk Factors in Childhood and Sex Differences in Prevalence of Carotid Artery Plaques and Intima-Media Thickness in Mid-Adulthood in the Childhood Determinants of Adult Health Study.

Background The origins of sex differences in cardiovascular diseases are not well understood. We examined the contribution of childhood risk factors to sex differences in adult carotid artery plaques and intima-media thickness (carotid IMT). Methods and Results Children in the 1985 Australian Schools Health and Fitness Survey were followed up when they were aged 36 to 49 years (2014-19, n=1085-1281). Log binomial and linear regression examined sex differences in adult carotid plaques (n=1089) or carotid IMT (n=1283). Childhood sociodemographic, psychosocial, and biomedical risk factors that might contribute to sex differences in carotid IMT/plaques were examined using purposeful model building with additional adjustment for equivalent adult risk factors in sensitivity analyses. Women less often had carotid plaques (10%) than men (17%). The sex difference in the prevalence of plaques (relative risk [RR] unadjusted 0.59 [95% CI, 0.43 to 0.80]) was reduced by adjustment for childhood school achievement and systolic blood pressure (RR adjusted 0.65 [95% CI, 0.47 to 0.90]). Additional adjustment for adult education and systolic blood pressure further reduced sex difference (RR adjusted 0.72 [95% CI, 0.49 to 1.06]). Women (mean±SD 0.61±0.07) had thinner carotid IMT than men (mean±SD 0.66±0.09). The sex difference in carotid IMT (ß unadjusted -0.051 [95% CI, -0.061 to -0.042]) reduced with adjustment for childhood waist circumference and systolic blood pressure (ß adjusted -0.047 [95% CI, -0.057 to -0.037]) and further reduced with adjustment for adult waist circumference and systolic blood pressure (ß adjusted -0.034 [95% CI, -0.048 to -0.019]). Conclusions Some childhood factors contributed to adult sex differences in plaques and carotid IMT. Prevention strategies across the life course are important to reduce adult sex differences in cardiovascular diseases.

Tracking of Cardiorespiratory Fitness and Physical Activity from Youth to Young Adulthood: Findings from the Prospective Special Turku Coronary Risk Factor Intervention Project (STRIP).

Using data from the Special Turku Coronary Risk Factor Intervention Project, cardiorespiratory fitness (rank-order correlation coefficient = 0.60-0.62) tracked stronger than physical activity (rank-order correlation coefficient = 0.27-0.38) between youth (age = 17 years) and young adulthood (age = 26 years). Cardiorespiratory fitness could help identify individuals at risk of maintaining poor fitness levels or developing adverse health in adulthood.

Top 10 International Priorities for Physical Fitness Research and Surveillance Among Children and Adolescents: A Twin-Panel Delphi Study.

BACKGROUND: The measurement of physical fitness has a history that dates back nearly 200 years. Recently, there has been an increase in international research and surveillance on physical fitness creating a need for setting international priorities that could help guide future efforts. OBJECTIVE: This study aimed to produce a list of the top 10 international priorities for research and surveillance on physical fitness among children and adolescents. METHODS: Using a twin-panel Delphi method, two independent panels consisting of 46 international experts were identified (panel 1 = 28, panel 2 = 18). The panel participants were asked to list up to five priorities for research or surveillance (round 1), and then rated the items from their own panel on a 5-point Likert scale of importance (round 2). In round 3, experts were asked to rate the priorities identified by the other panel. RESULTS: There was strong between-panel agreement (panel 1: rs = 0.76, p < 0.01; panel 2: rs = 0.77, p < 0.01) in the priorities identified. The list of the final top 10 priorities included (i) "conduct longitudinal studies to assess changes in fitness and associations with health". This was followed by (ii) "use fitness surveillance to inform decision making", and (iii) "implement regular and consistent international/national fitness surveys using common measures". CONCLUSIONS: The priorities identified in this study provide guidance for future international collaborations and research efforts on the physical fitness of children and adolescents over the next decade and beyond.

Childhood Factors Associated with Muscular Strength Trajectories between Childhood and Mid-Adulthood.

PURPOSE: To promote greater muscular strength across the life course and, in turn, help improve long-term health outcomes, strategies aimed at increasing muscular strength are required. To inform these strategies, this study identified childhood factors associated with muscular strength trajectories. METHODS: Prospective longitudinal study of 1280 Childhood Determinants of Adult Health participants who had a range of potentially modifiable factors (e.g., anthropometric measures, physical activity) and health and risk motivation items (e.g., attitudes, beliefs, and intentions on health-related actions) measured in childhood and had their muscular strength assessed up to three times between childhood and midlife. Associations between childhood factors and three predetermined life course muscular strength trajectories (identified previously using group-base trajectory modeling as follows: above average and increasing, average, and below average and decreasing) were examined using log multinomial regression. RESULTS: Greater physical fitness, physical activity, fat-free mass, enjoyment of physical activity, physical education, and school sports, and positive attitudes regarding the importance of exercising, staying fit, and body image were associated with a lower likelihood of being in the below average and decreasing muscular strength trajectory (relative risk range, 0.45-0.98). Greater physical fitness, physical activity, and fat-free mass, and attending an independent school were associated with a higher likelihood of being in the above average and increasing muscular strength trajectory (relative risk range, 1.03-1.93). CONCLUSIONS: In addition to providing health benefits in the short term, physical activity, physical fitness, positive health attitudes, and healthy weight in childhood may lead to better muscular strength in the long term.