Lifetime exposure to air pollution and academic achievement: A nationwide cohort study in Denmark.

Recent research suggests a link between air pollution and cognitive development in children, and studies on air pollution and academic achievement are emerging. We conducted a nationwide cohort study in Denmark to explore the associations between lifetime exposure to air pollution and academic performance in 9th grade. The study encompassed 785,312 children born in Denmark between 1989 and 2005, all of whom completed 9th-grade exit examinations. Using linear mixed models with a random intercept for each school, we assessed the relationship between 16 years of exposure to PM2.5, PM10, and gaseous pollutants and Grade Point Averages (GPA) in exit examinations, covering subjects such as Danish literature, Danish writing, English, mathematics, and natural sciences. The study revealed that a 5 µg/m3 increase in PM2.5 and PM10 was associated with a decrease of 0.99 (95 % Confidence Intervals: -1.05, -0.92) and 0.46 (-0.50, -0.41) in GPA, respectively. Notably, these negative associations were more pronounced in mathematics and natural sciences compared to language-related subjects. Additionally, girls and children with non-Danish mothers were found to be particularly susceptible to the adverse effects of air pollution exposure. These results underscore the potential long-term consequences of air pollution on academic achievement, emphasizing the significance of interventions that foster healthier environments for children's cognitive development.

The Danish Aging and Cognition (DanACo) cohort.

BACKGROUND: With aging populations worldwide, identification of predictors of age-related cognitive decline is becoming increasingly important. The Danish Aging and Cognition Cohort (DanACo) including more than 5000 Danish men was established to investigate predictors of age-related cognitive decline from young adulthood to late mid-life. CONSTRUCTION AND CONTENT: The DanACo cohort was established through two separate data collections with identical designs involving a follow-up examination in late mid-life of men for whom intelligence test scores were available from their mandatory conscription board examination. The cohort consists of 5,183 men born from 1949 through 1961, with a mean age of 20.4 years at baseline and a mean age of 64.4 years at follow-up. The baseline measures consisted of height, weight, intelligence test score and educational level collected at the conscription board examination. The follow-up assessment consisted of a re-administration of the same intelligence test and a comprehensive questionnaire covering socio-demographic factors, lifestyle, and health-related factors. The data were collected in test sessions with up to 24 participants per session. Using the unique personal identification number assigned to all Danes, the cohort has been linked to data from national administrative and health registers for prospectively collected data on socioeconomic and health-related factors. UTILITY AND DISCUSSION: The DanACo cohort has some major strengths compared to existing cognitive aging cohorts such as a large sample size (n = 5,183 men), a validated global measure of cognitive ability, a long retest interval (mean 44.0 years) and the availability of prospectively collected data from registries as well as comprehensive questionnaire data. The main weakness is the low participation rate (14.3%) and that the cohort consists of men only. CONCLUSION: Cognitive decline is a result of a summary of factors across the life-course. The DanACo cohort is characterized by a long retest interval and contains data on a wealth of factors across adult life which is essential to establish evidence on predictors of cognitive decline. Moreover, the size of the cohort ensures sufficient statistical power to identify even relatively weak predictors of cognitive decline.

Early Motor Developmental Milestones and Personality Traits in Midlife: A 50-Year Follow-Up Study.

Background The purpose of this study was to investigate if infants' age at attaining motor developmental milestones is associated with the big five personality traits 50 years later. Methods Mothers of 8395 infants from the Copenhagen Perinatal Cohort recorded a total of 12 motor developmental milestones during the first year of their infant's life. Information on at least one milestone was available for 1307 singletons with adult follow-up scores on the NEO-Five-Factor Inventory. The mean age at personality testing was 50.1 years. Results Slower attainment of motor milestones was associated with increased neuroticism and lower conscientiousness in midlife. All 12 motor developmental milestones explained a total of 2.4% of the variance in neuroticism, while they explained 3.2% of the variance in conscientiousness. These results remained significant after adjustment for the included family and perinatal covariates, as well as adult intelligence. Discussion The personality trait of neuroticism is a general risk factor for psychopathology and has in young adulthood been found to be associated with early motor development. However, evidence on associations of motor developmental milestones with other personality traits has been non-existent. These findings suggest that delays in early motor development may not only characterise individuals with later psychopathology, including schizophrenia, but may also be associated with personality traits such as neuroticism and conscientiousness through the life course.

Mental health trajectories after juridical divorce: Does personality matter?

INTRODUCTION: This study investigated whether the Big Five personality dimensions were associated with mental health trajectories and/or intervention effects of a digital divorce intervention from juridical divorce to 12 months following juridical divorce. The study utilized a randomized controlled trial study design (N = 676) and measured mental health outcomes (anxiety, depression, somatization, and stress) at study inclusion (i.e., at juridical divorce) and 3-, 6-, and 12 months after juridical divorce. Big Five personality dimensions were measured 1 month post study inclusion. RESULTS: The study found that neuroticism is the personality dimension most predictive of post-divorce mental health outcomes. Specifically, divorcees with higher neuroticism scores indicated worse mental health immediately following divorce, but their symptom levels decreased more rapidly over a 12 months period after juridical divorce compared with lower neuroticism divorcees. It is also notable that their mean scores for the mental health outcomes remained higher at all time points (3, 6, and 12 months post baseline), relative to those lower in neuroticism. CONCLUSION: Findings are discussed in light of divorce-adjustment-theory and the stress-buffering model.

Social, psychological and health characteristics associated with stability and change in adult alcohol consumption.

BACKGROUND: Many studies analyzing health effects of alcohol consumption have operationalized alcohol intake from a single baseline measure without further follow-up. Consequently, there is a lack of knowledge about stability and change in alcohol consumption over the life course and the social, psychological, lifestyle, and health characteristics associated with different alcohol consumption trajectories. OBJECTIVES: The aims of the study were to describe the prevalence of different adult-life alcohol consumption trajectories among Danish men and to analyze social, psychological, lifestyle and health characteristics associated with these trajectories. METHODS: For 2510 Danish men, retrospective decade-based information on alcohol consumption during life period 26-60 years was obtained in late midlife and information on individual characteristics was obtained in young adulthood, late midlife and from national hospital registries. The men were allocated to one of six a priori defined alcohol consumption trajectories. RESULTS: About 65% of Danish men had a stable moderate consumption, drinking 1-21 units weekly while the five other consumption trajectories were comparatively rare: 3% stable abstainers, 4.7% stable high-risk drinkers, 10.9% with increasing and 12.7% with decreasing consumption. Moderate consumption over the adult life-course was associated with the most favorable social, psychological, lifestyle and health characteristics while the other trajectories were generally associated with less favorable characteristics to varying degrees-e. g. this was the case for the stable abstaining trajectory and in particular the trajectory with decreasing consumption. CONCLUSION: The findings suggest that the majority of Danish men drink moderately in the life period from young adulthood to late midlife, and deviance from this 'normal' moderate consumption trajectory is associated with less favorable social, psychological, lifestyle and health characteristics. Some of these characteristics may influence alcohol consumption patterns, but for some of the trajectories, alcohol consumption may influence health as well as social and psychological functioning.

Prospective associations between alcohol consumption and psychological well-being in midlife.

BACKGROUND: Alcohol consumption potentially influences psychological well-being in beneficial and harmful ways, but prospective studies on the association show mixed results. Our main purpose was to examine prospective associations between alcohol consumption and psychological well-being in middle-aged men and women. METHODS: The study sample included 4148 middle-aged individuals (80% men) from the Copenhagen Aging and Midlife Biobank who reported their alcohol consumption (average weekly consumption and frequency of binge drinking) at baseline in 2004 or 2006 and reported their psychological well-being (satisfaction with life and vitality) at follow-up in 2009-2011. Analyses were adjusted for sociodemographic factors, lifestyle, social relations, and morbidity. RESULTS: For satisfaction with life at follow-up, lower scores were observed in men and women who were alcohol abstinent at baseline as well as in men with heavy alcohol consumption compared with moderate alcohol consumption at baseline. Moreover, men with weekly binge drinking at baseline had lower satisfaction with life scores at follow-up than men with moderate frequency of binge drinking (1-3 times/month). In relation to vitality at follow-up, alcohol abstinence at baseline in men and women and heavy alcohol consumption at baseline in men were associated with lower scores compared with moderate alcohol consumption (yet in men these findings were not robust to adjustment for covariates). CONCLUSIONS: Alcohol abstinence seems to be prospectively associated with adverse psychological well-being (vitality and life satisfaction) in men and women, while heavy alcohol consumption seems to be prospectively associated with adverse satisfaction with life in men. Finally, a prospective association between weekly binge drinking and lower life satisfaction was observed in men.

Longitudinal associations of self-reported satisfaction with life and vitality with risk of mortality.

OBJECTIVE: The aims of the current study were to investigate the associations between two aspects of well-being - satisfaction with life and vitality - and all-cause mortality, and examine the impact of potential confounding factors on the associations. METHODS: Baseline satisfaction with life was assessed using the Satisfaction With Life Scale (n = 7058) and vitality was assessed using the Short-Form 36 vitality subscale (n = 6987). The study sample consisted of midlife participants from the Copenhagen Aging and Midlife Biobank (CAMB) study conducted from 2009 to 2011. Deaths (n = 312) in the study sample in the follow-up period (mean of 8.6 years) were assessed using Danish register data. The hazard ratios of all-cause mortality according to satisfaction with life and vitality scores adjusted for potential covariates were examined with proportional hazard regression. RESULTS: A one standard deviation increase on the SWLS and the SF-36 vitality scale was associated with a 39% (HR = 0.61, 95% CI = 0.55-0.67) and 40% (HR = 0.60, 95% CI = 0.54-0.66) decreased risk of mortality respectively, after adjustment for baseline sociodemographic factors. The associations remained significant after separate adjustment for lifestyle (SWLS: HR = 0.67, SF-36 vitality: HR = 0.67), health (SWLS: HR = 0.65, SF-36 vitality: HR = 0.64), depressive symptoms (SWLS: HR = 0.72, SF-36 vitality: HR = 0.71) and social factors (SWLS: HR = 0.76, SF-36 vitality: HR = 0.69). CONCLUSIONS: Satisfaction with life and vitality are of predictive value for mortality, independently of sociodemographics, lifestyle, health, depressive symptoms, and social factors.

Satisfaction with life and SF-36 vitality predict risk of ischemic heart disease: a prospective cohort study.

The main objective of the current study was to investigate associations between two aspects of well-being - satisfaction with life and vitality - and incidence of and mortality from ischemic heart disease. Study design. The Copenhagen Aging and Midlife Biobank (CAMB) was conducted from 2009 to 2011 and was used as baseline data with 6750 individuals having complete information on The Satisfaction with Life Scale (SWLS) and 6652 individuals with complete information on the Short Form Health Survey (SF-36) vitality scale. Incidence of and mortality from ischemic heart disease were assessed using Danish register data and a total of 349 CAMB individuals were registered with either a diagnosis (n = 337) or had died (n = 12) from ischemic heart disease before the end of follow-up (31 December 2017). The hazard ratios of ischemic heart disease according to satisfaction with life and vitality scores were investigated using Cox proportional hazard regression adjusted for potential covariates. Results. A one standard deviation increase on the SWLS was associated with an 18% reduced risk of ischemic heart disease while a one standard deviation increase on the SF-36 vitality scale was associated with a 24% reduced risk of ischemic heart disease after adjustment for baseline socio-demographic factors. These associations remained when separately adjusting for lifestyle, objective health, and social factors, but became non-significant when adjusting for self-reported health. Conclusion. Our study indicates that both psychological and health-related components of wellbeing are important in relation to ischemic heart disease.

Does meaning protect against loneliness? Exploring empirical studies and theory.

Research indicates that meaning in life is a protective factor for physical and mental health. Although loneliness is increasingly recognized as an important public health concern, no studies have investigated the potential of meaning in life to protect against loneliness. Based on an explorative interdisciplinary research strategy that comprises data from a cohort study, a strategic review of empirical literature and a conceptual analysis of the concept of meaning in life we explore the support for potential links between meaning in life and the protection against loneliness. We propose three different explanatory mechanisms; (i) that meaning in life promotes a positive orientation toward others, (ii) that meaning in life enhances interpersonal appeal and (iii) that meaning in life promotes a better ability to cope with loneliness. Theoretically, we explore the idea that the value of meaning in life ultimately concerns a social need to contribute to the realization of value that, at least in principle, can be shared and recognized by others. When people realize the value of meaning in life, they partake in a community of shared values, which links them to a social world in a way that may protect against the feeling of loneliness. Jointly the analyses point to the need for prospective studies on the role of meaning in life as a protective factor against loneliness and a potential novel focus for loneliness interventions.

Maintenance of muscle strength following a one-year resistance training program in older adults.

BACKGROUND: Muscle mass, strength and function declines with advancing age. Strength training (ST) improves these parameters in older adults, but the gains often disappear after completion of a short-term intervention. The purpose of the present study was to investigate muscle mass, -strength and -function one year after the completion of a successful long-term (12 months) supervised ST program in older adults. METHOD: Men and women (n = 419, age: 62-70 years) completed one year of supervised heavy resistance training (HRT, n = 143) or moderate intensity resistance training (MIT, n = 144) and were compared to a non-exercising control group (CON, n = 132). At 1-year follow-up, 398 participants returned for measurements of muscle power, -strength and -mass, physical function, body composition, hippocampus volume and physical/mental well-being. The results were compared to pre-training (baseline) and post-training (1-year) values. Further, the participants from the two previous training groups (HRT + MIT, n = 265) were divided into 1) those who on their own continued the ST program (>9 months) the year after completion of the supervised ST program (CONTIN, n = 65) and 2) those who stopped during the follow-up year (<9 months) (STOP, n = 200). RESULTS: Out of all the improvements obtained after the 1-year training intervention, only knee extensor muscle strength in HRT was preserved at 1-year follow-up (p < 0.0001), where muscle strength was 7% higher than baseline. Additionally, the decrease in muscle strength over the second year was lower in CONTIN than in STOP with decreases of 1% and 6%, respectively (p < 0.05). Only in CONTIN was the muscle strength still higher at 1-year follow-up compared with baseline with a 14% increase (p < 0.0001). The heavy strength training induced increase in whole-body lean mass was erased at 1-year follow-up. However, there was a tendency for maintenance of the cross-sectional area of m. vastus lateralis from baseline to 1-year follow-up in HRT compared with CON (p = 0.06). Waist circumference decreased further over the second year in CONTIN, whereas it increased in STOP (p < 0.05). CONCLUSION: Even though long-term strength training effectively improved muscle function and other health parameters in older adults, only knee extensor muscle strength was preserved one year after completion of heavy (but not moderate intensity) resistance training. Continuation of strength training resulted in better maintenance of muscle strength and health, which indicates that it is required to continue with physical activity to benefit from the long-term effects of strength training upon muscle function and health in older men and women.

The influence of prolonged strength training upon muscle and fat in healthy and chronically diseased older adults.

BACKGROUND: Physical muscle function and brain hippocampus size declines with age, accelerating after the age of 60. Strength training over a few months improves physical function, but less is known about how long-term strength training affects physical function and hippocampus volume. Therefore, we aimed to investigate the effect of 1-year strength training of two different intensities upon muscle mass, function, and hippocampus volume in retirement-age individuals. METHODS: In this multidisciplinary randomized controlled trial (clinicaltrials.gov: NCT02123641), participants were allocated to either a) supervised, heavy resistance training (HRT, n = 149, 3/wk), b) moderate intensity resistance training (MIT, n = 154, 3/wk) or c) non-exercise activities (CON, n = 148). 451 participants were randomized (62-70 yrs., women 61%, ≈80% with a chronic medical disease) and 419 were included in the intention-to-treat analysis (n = 143, 144 and 132; HRT, MIT and CON). Changes in muscle power (primary outcome), strength and size, physical function, body composition, hippocampus volume and physical/mental well-being were analyzed. FINDINGS: Of the participants (HRT + MIT), 83% completed training at least 2/week. Leg extensor power was unchanged in all groups, but strength training had a positive effect on isometric knee extensor strength in both groups, whereas an increased muscle mass, cross-sectional area of vastus lateralis muscle, a decreased whole-body fat percentage, visceral fat content and an improved mental health (SF-36) occurred in HRT only. Further, chair-stand performance improved in all groups, whereas hippocampus volume decreased in all groups over time with no influence of strength training. INTERPRETATION: Together, the results indicate that leg extensor power did not respond to long-term supervised strength training, but this type of training in a mixed group of healthy and chronically diseased elderly individuals can be implemented with good compliance and induces consistent changes in physiological parameters of muscle strength, muscle mass and abdominal fat.

Birth weight and quality of life in midlife: a 50-year follow-up study of 2079 individuals in Denmark.

PURPOSE: Low birth weight has been associated with a higher risk of reduced quality of life (QoL) in children, adolescents, and young adults, but the influence seems to diminish over time. However, previous studies have mainly focused on health-related QoL and compared individuals with low birth weight with individuals without low birth weight. The purpose of the present cohort study was to investigate the influence of the entire range of birth weights on three distinct measures of QoL in midlife. METHODS: The study population consisted of all live-born singletons from the Copenhagen Perinatal Cohort (CPC, 1959-1961) who participated in a 50-year follow-up examination in 2009-2011 (N = 2079). Birth weight was measured by three pediatricians at birth. QoL was measured at the follow-up by the participants' scores on three QoL self-report measures: The Satisfaction With Life Scale, the Vitality Scale of the Medical Outcomes Study 36-Item Short-Form Health Survey, and a single-item QoL measure based on the question: "How is your quality of life at the moment?". General linear regression and binary logistic regression were used to estimate the association between birth weight and QoL in midlife. RESULTS: Small, curvilinear associations of birth weight with life satisfaction, vitality, and the single-item QoL measure were found, suggesting that both low and high birth weights increase the risk of low satisfaction with life, low vitality and low QoL. CONCLUSION: The study findings suggest that low and high-range birth weight exert a lasting influence on distinct, but complementary aspects of QoL in midlife.

The association between life satisfaction, vitality, self-rated health, and risk of cancer.

PURPOSE: Only few prospective studies have been conducted on the contribution of quality of life-related factors to the risk of cancer. The aim of this study was to investigate the prospective associations of three quality of life-related factors with the risk of cancer; life satisfaction, vitality, and self-rated health. METHODS: In 2009-2011, 7189 participants in the Copenhagen Aging and Midlife Biobank were asked to rate their life satisfaction, their vitality, and their health. The study population was followed until the end of 2015 for registration of cancer in the Danish National Patient Register. RESULTS: During the follow-up period, cancer was diagnosed in 312 individuals. Life satisfaction was not associated with the risk of cancer. Vitality was significantly associated with the risk of cancer, but the association became non-significant after adjustment for age, sex, socioeconomic position, and lifestyle factors. However, when additionally adjusting for life satisfaction, individuals who rated their vitality as low had a hazard ratio of 1.46 (95% confidence interval [CI] 1.04-2.07) for the development of cancer. Individuals who rated their health as poor had a hazard ratio of 1.70 (95% CI 1.27-2.26) for the development of cancer, compared with individuals with good, very good, or excellent self-rated health. The association remained significant after adjustment for basic confounders, life satisfaction, and vitality. CONCLUSION: A better grasp of the significance of quality of life-related factors for the risk of cancer may be of great importance to population-based cancer prevention that aims to target early risk factors for development of cancer across widespread cancer sites.

Prospective Associations of the Short Form Health Survey Vitality Scale and Changes in Body Mass Index and Obesity Status.

Objectives: The objectives of the current study were to prospectively investigate the predictive value of the vitality scale of the Short Form Health Survey for changes in body mass index and development of obesity. Methods: The study population comprised 2864 (81.5%) men and 648 (18.5%) women from the Metropolit Project and the Danish Longitudinal Study on Work, Unemployment and Health, who participated in a follow-up examination in 2009-2011 corresponding to a follow-up period of 3-7 years. Associations of vitality with body mass index and obesity were investigated separately for men and women in linear and logistic regression models adjusting for age, baseline body mass index, education, physical activity, smoking, and obesity-related diseases. Results: Vitality was significantly associated with change in body mass index among men (p < 0.001) and women (p < 0.05) gaining weight after adjusting for age, baseline body mass index, education, physical activity, smoking, and obesity-related diseases. No significant associations of vitality with BMI change were observed among individuals maintaining or losing weight during the follow-up period. Furthermore, vitality significantly predicted development of obesity among women. Conclusion: The study indicates that vitality is of predictive value for increases in BMI over time among individuals gaining weight and may further predict the development of obesity among women. This identification of poor vitality as a potential risk indicator for weight gain and development of obesity may be beneficial in clinical practice.

Associations of Personality with Body Mass Index and Obesity in a Large Late Midlife Community Sample.

OBJECTIVE: The study examined cross-sectional associations of personality with BMI and obesity among men and women in a large late midlife community sample. METHODS: The sample comprised 5,286 Danish individuals aged 49-63 years from the Copenhagen Ageing and Midlife Biobank (CAMB) with complete information on measured BMI, personality assessed by the NEO Five Factor Inventory (NEO FFI), and sociodemographic factors including sex, age and educational length. Analysis of variance and logistic regression models were used to investigate associations between personality and BMI as well as obesity. Personality traits were analyzed separately and combined in the same model. RESULTS: All personality traits except for neuroticism were significantly associated with BMI, with extraversion (p value ranged from <0.001 to 0.012) and agreeableness (p value ranged from 0.001 to 0.002) being the most consistent predictors of BMI among men and women, respectively. Furthermore, extraversion among men (high scores) (p = 0.016) and agreeableness among women (low scores) (p = 0.026) were the only personality traits significantly associated with obesity when adjusting for duration of education. CONCLUSION: Personality was significantly associated with BMI and to a lesser extent with obesity, and these associations differed between men and women. Also, it was suggested that the interrelations of the five personality traits should be considered in future research of personality and health outcomes.

Does vital exhaustion increase the risk of type 2 diabetes? A prospective study.

BACKGROUND: There is evidence that both stress and depression have a causal relationship with type 2 diabetes suggesting that vital exhaustion (VE) too could be a risk factor. The association between VE and type 2 diabetes has, however, not been investigated prospectively. AIM: To prospectively investigate whether VE is associated with an increased risk of type 2 diabetes in a Danish population. METHODS: A prospective cohort study based on the Copenhagen City Heart Study (1991-1993). The degree of VE was measured among 9075 participants without type 1 or 2 diabetes at baseline. To detect type 2 diabetes in the follow-up period, two different approaches were used: In the first substudy, type 2 diabetes was defined based on blood samples and questionnaires from a follow-up study in 2001-2003 (N=4708). The second substudy was register-based, and the study population was linked to the Danish Hospital Discharge Register to detect registrations with type 2 diabetes until 2014. RESULTS: A high degree of VE was associated with an increased risk of developing type 2 diabetes in both substudies. In the first substudy, the OR for developing type 2 diabetes was 2.56 (95% CI, 1.53; 4,29, P<0,001) among the quartile of participants reporting the highest degree of VE. In the second substudy, the OR was 1.31 (95% CI, 0.99; 1.72, P=0.053) for this group. CONCLUSION: The results indicate that VE may be a useful measure in clinical practice in order to discover individuals at risk of type 2 diabetes.

Associations between obesity and mental distress in late midlife: results from a large Danish community sample.

BACKGROUND: To examine associations of Body mass Index (BMI) and mental distress in late midlife in a large Danish community sample and to investigate the effect of socio-demographic factors. METHODS: The study sample comprised 3613 Danish men and 1673 women aged 49-63 years from the Copenhagen Ageing and Midlife Biobank (CAMB) with complete information on measured BMI, severity of mental symptoms assessed by the Symptom Check-List' (SCL-90), and socio-demographic factors including sex, age, occupational social class, and educational duration. Linear and logistic regression were used to evaluate associations between BMI category and SCL-90. RESULTS: Unadjusted SCL-90 subscale scores differed significantly across BMI categories (p < 0.001) among both men and women with more mental distress in the underweight, obese and severely obese BMI categories except for the anxiety scale which was not associated with BMI category in women. In the adjusted analyses, all symptom scales remained significantly associated with BMI among men after adjusting for socio-demographic factors while only associations with somatization and depression scales remained significant for women.. When SCL-90 case status was applied as an outcome, significant unadjusted associations with BMI category were observed for somatization (p < 0.001), depression (p = 0.026) and the General Severity Index (p = 0.002) among men and somatization (p = 0.002) among women. Furthermore, somatization case-status was significantly predicted by BMI category (p < 0.001) in men after adjusting for socio-demographic factors. CONCLUSION: Results indicate more mental distress among underweight, obese and severely obese men and women after adjusting for socio-demographic factors. Furthermore, obese men have higher risk of reporting clinically relevant symptoms of somatization independently of socio-demographic factors.

Physical activity as intervention for age-related loss of muscle mass and function: protocol for a randomised controlled trial (the LISA study).

INTRODUCTION: Physical and cognitive function decline with age, accelerating during the 6th decade. Loss of muscle power (force×velocity product) is a dominant physical determinant for loss of functional ability, especially if the lower extremities are affected. Muscle strength training is known to maintain or even improve muscle power as well as physical function in older adults, but the optimal type of training for beneficial long-term training effects over several years is unknown. Moreover, the impact of muscle strength training on cognitive function and brain structure remains speculative. The primary aim of this randomised controlled trial is to compare the efficacy of two different 1 year strength training regimens on immediate and long-lasting improvements in muscle power in retirement-age individuals. Secondary aims are to evaluate the effect on muscle strength, muscle mass, physical and cognitive function, mental well-being, health-related quality of life and brain morphology. METHODS AND ANALYSIS: The study includes 450 home-dwelling men and women (62-70 years). Participants are randomly allocated to (1) 1 year of supervised, centre-based heavy resistance training, (2) home-based moderate intensity resistance training or (3) habitual physical activity (control). Changes in primary (leg extensor power) and secondary outcomes are analysed according to the intention to treat principle and per protocol at 1, 2, 4, 7 and 10 years. ETHICS AND DISSEMINATION: The study is expected to generate new insights into training-induced promotion of functional ability and independency after retirement and will help to formulate national recommendations regarding physical activity schemes for the growing population of older individuals in western societies. Results will be published in scientific peer-reviewed journals, in PhD theses and at public meetings. The study is approved by the Regional Ethical Committee (Capital Region, Copenhagen, Denmark, number H-3-2014-017). TRIAL REGISTRATION NUMBER: NCT02123641.