High-Fidelity Detection of Large-Scale Atom Arrays in an Optical Lattice.

Recent advances in quantum simulation based on neutral atoms have largely benefited from high-resolution, single-atom sensitive imaging techniques. A variety of approaches have been developed to achieve such local detection of atoms in optical lattices or optical tweezers. For alkaline-earth and alkaline-earth-like atoms, the presence of narrow optical transitions opens up the possibility of performing novel types of Sisyphus cooling, where the cooling mechanism originates from the capability to spatially resolve the differential optical level shifts in the trap potential. Up to now, it has been an open question whether high-fidelity imaging could be achieved in a "repulsive Sisyphus" configuration, where the trap depth of the ground state exceeds that of the excited state involved in cooling. Here, we demonstrate high-fidelity (99.971(1)%) and high-survival (99.80(5)%) imaging of strontium atoms using repulsive Sisyphus cooling. We use an optical lattice as a pinning potential for atoms in a large-scale tweezer array with up to 399 tweezers and show repeated, high-fidelity lattice-tweezer-lattice transfers. We furthermore demonstrate loading the lattice with approximately 10 000 atoms directly from the MOT and scalable imaging over >10 000 lattice sites with a combined survival probability and classification fidelity better than 99.2%. Our lattice thus serves as a locally addressable and sortable reservoir for continuous refilling of optical tweezer arrays in the future.

Rydberg Macrodimers: Diatomic Molecules on the Micrometer Scale.

Controlling molecular binding at the level of single atoms is one of the holy grails of quantum chemistry. Rydberg macrodimers─bound states between highly excited Rydberg atoms─provide a novel perspective in this direction. Resulting from binding potentials formed by the strong, long-range interactions of Rydberg states, Rydberg macrodimers feature bond lengths in the micrometer regime, exceeding those of conventional molecules by orders of magnitude. Using single-atom control in quantum gas microscopes, the unique properties of these exotic states can be studied with unprecedented control, including the response to magnetic fields or the polarization of light in their photoassociation. The high accuracy achieved in spectroscopic studies of macrodimers makes them an ideal testbed to benchmark Rydberg interactions, with direct relevance to quantum computing and information protocols where these are employed. This review provides a historic overview and summarizes the recent findings in the field of Rydberg macrodimers. Furthermore, it presents new data on interactions between macrodimers, leading to a phenomenon analogous to Rydberg blockade at the level of molecules, opening the path toward studying many-body systems of ultralong-range Rydberg molecules.

Mid-Circuit Cavity Measurement in a Neutral Atom Array.

Subsystem readout during a quantum process, or mid-circuit measurement, is crucial for error correction in quantum computation, simulation, and metrology. Ideal mid-circuit measurement should be faster than the decoherence of the system, high-fidelity, and nondestructive to the unmeasured qubits. Here, we use a strongly coupled optical cavity to read out the state of a single tweezer-trapped ^{87}Rb atom within a small tweezer array. Measuring either atomic fluorescence or the transmission of light through the cavity, we detect both the presence and the state of an atom in the tweezer, within only tens of microseconds, with state preparation and measurement infidelities of roughly 0.5% and atom loss probabilities of around 1%. Using a two-tweezer system, we find measurement on one atom within the cavity causes no observable hyperfine-state decoherence on a second atom located tens of microns from the cavity volume. This high-fidelity mid-circuit readout method is a substantial step toward quantum error correction in neutral atom arrays.

Quantum gas microscopy of Kardar-Parisi-Zhang superdiffusion.

The Kardar-Parisi-Zhang (KPZ) universality class describes the coarse-grained behavior of a wealth of classical stochastic models. Surprisingly, KPZ universality was recently conjectured to also describe spin transport in the one-dimensional quantum Heisenberg model. We tested this conjecture by experimentally probing transport in a cold-atom quantum simulator via the relaxation of domain walls in spin chains of up to 50 spins. We found that domain-wall relaxation is indeed governed by the KPZ dynamical exponent z = 3/2 and that the occurrence of KPZ scaling requires both integrability and a nonabelian SU(2) symmetry. Finally, we leveraged the single-spin-sensitive detection enabled by the quantum gas microscope to measure an observable based on spin-transport statistics. Our results yield a clear signature of the nonlinearity that is a hallmark of KPZ universality.

Realizing Distance-Selective Interactions in a Rydberg-Dressed Atom Array.

Measurement-based quantum computing relies on the rapid creation of large-scale entanglement in a register of stable qubits. Atomic arrays are well suited to store quantum information, and entanglement can be created using highly-excited Rydberg states. Typically, isolating pairs during gate operation is difficult because Rydberg interactions feature long tails at large distances. Here, we engineer distance-selective interactions that are strongly peaked in distance through off-resonant laser coupling of molecular potentials between Rydberg atom pairs. Employing quantum gas microscopy, we verify the dressed interactions by observing correlated phase evolution using many-body Ramsey interferometry. We identify atom loss and coupling to continuum modes as a limitation of our present scheme and outline paths to mitigate these effects, paving the way towards the creation of large-scale entanglement.

Superresolution Microscopy of Optical Fields Using Tweezer-Trapped Single Atoms.

We realize a scanning probe microscope using single trapped ^{87}Rb atoms to measure optical fields with subwavelength spatial resolution. Our microscope operates by detecting fluorescence from a single atom driven by near-resonant light and determining the ac Stark shift of an atomic transition from other local optical fields via the change in the fluorescence rate. We benchmark the microscope by measuring two standing-wave Gaussian modes of a Fabry-Pérot resonator with optical wavelengths of 1560 and 781 nm. We attain a spatial resolution of 300 nm, which is superresolving compared to the limit set by the 780 nm wavelength of the detected light. Sensitivity to short length scale features is enhanced by adapting the sensor to characterize an optical field via the force it exerts on the atom.

Waterpipe Use among Adolescents in Germany: Prevalence, Associated Consumer Characteristics, and Trends (German Health Interview and Examination Survey for Children and Adolescents, KiGGS).

Waterpipe (WP) use is popular among youth worldwide, but epidemiological data from Germany are scarce. We aimed to describe prevalence rates of WP use (current, last 12 months, ever) and analysed correlates and trends among 11- to 17-year-olds in Germany. Analyses were based on data from the "German Health Interview and Examination Survey for Children and Adolescents" study during 2014-2017 (n = 6599). Changes in WP use prevalence compared with 2009-2012 were used to describe trends. Associations with sociodemographic characteristics and cigarette smoking were assessed with multivariable logistic regression models. Prevalence of current WP use among adolescents was 8.5% (95% confidence interval (CI) = 7.5-9.6), use in the last 12 months was 19.7% (95% CI = 18.3-21.2), and ever use was 25.8% (95% CI = 24.2-27.5). High prevalence rates were particularly found among 16-17-year-olds. During 2009-2012, these prevalence rates were 9.0%, 18.5%, and 26.1%, respectively. WP use was associated with older age, male sex, migration background, lower educational level, and current smoking status. Among current WP users, 66.2% (95% CI = 60.0-71.9) identified themselves as non-smokers, and 38.1% (95% CI = 32.5-44.0) had used WP ≥ three times in the last month. WP consumption is popular among German youth, and prevalence rates have not changed over time. Specific prevention strategies to reduce harmful WP consumption among youth should be implemented.

A subradiant optical mirror formed by a single structured atomic layer.

Versatile interfaces with strong and tunable light-matter interactions are essential for quantum science1 because they enable mapping of quantum properties between light and matter1. Recent studies2-10 have proposed a method of controlling light-matter interactions using the rich interplay of photon-mediated dipole-dipole interactions in structured subwavelength arrays of quantum emitters. However, a key aspect of this approach-the cooperative enhancement of the light-matter coupling strength and the directional mirror reflection of the incoming light using an array of quantum emitters-has not yet been experimentally demonstrated. Here we report the direct observation of the cooperative subradiant response of a two-dimensional square array of atoms in an optical lattice. We observe a spectral narrowing of the collective atomic response well below the quantum-limited decay of individual atoms into free space. Through spatially resolved spectroscopic measurements, we show that the array acts as an efficient mirror formed by a single monolayer of a few hundred atoms. By tuning the atom density in the array and changing the ordering of the particles, we are able to control the cooperative response of the array and elucidate the effect of the interplay of spatial order and dipolar interactions on the collective properties of the ensemble. Bloch oscillations of the atoms outside the array enable us to dynamically control the reflectivity of the atomic mirror. Our work demonstrates efficient optical metamaterial engineering based on structured ensembles of atoms4,8,9 and paves the way towards controlling many-body physics with light5,6,11 and light-matter interfaces at the single-quantum level7,10.

Domain-specific physical activity patterns and cardiorespiratory fitness among the working population: Findings from the cross-sectional German Health Interview and Examination Survey.

OBJECTIVES: This study aimed to investigate associations between occupational physical activity patterns (physical work demands linked to job title) and leisure time physical activity (assessed by questionnaire) with cardiorespiratory fitness (assessed by exercise test) among men and women in the German working population. DESIGN: Population-based cross-sectional study. SETTING: Two-stage cluster-randomised general population sample selected from population registries of 180 nationally distributed sample points. Information was collected from 2008 to 2011. PARTICIPANTS: 1296 women and 1199 men aged 18-64 from the resident working population. OUTCOME MEASURE: Estimated low maximal oxygen consumption ([Formula: see text]), defined as first and second sex-specific quintile, assessed by a standardised, submaximal cycle ergometer test. RESULTS: Low estimated [Formula: see text] was strongly linked to low leisure time physical activity, but not occupational physical activity. The association of domain-specific physical activity patterns with low [Formula: see text] varied by sex: women doing no leisure time physical activity with high occupational physical activity levels were more likely to have low [Formula: see text] (OR 6.54; 95% CI 2.98 to 14.3) compared with women with ≥2 hours of leisure time physical activity and high occupational physical activity. Men with no leisure time physical activity and low occupational physical activity had the highest odds of low [Formula: see text] (OR 4.37; 95% CI 2.02 to 9.47). CONCLUSION: There was a strong association between patterns of leisure time and occupational physical activity and cardiorespiratory fitness within the adult working population in Germany. Women doing no leisure time physical activity were likely to have poor cardiorespiratory fitness, especially if they worked in physically demanding jobs. However, further investigation is needed to understand the relationships between activity and fitness in different domains. Current guidelines do not distinguish between activity during work and leisure time, so specifying leisure time recommendations by occupational physical activity level should be considered.

Individual and interpersonal correlates of cardiorespiratory fitness in adults - Findings from the German Health Interview and Examination Survey.

Cardiorespiratory fitness (CRF) is an established predictor of adverse health outcomes. The aim of this study is to investigate potential behavioral, interpersonal and socioeconomic correlates of CRF among men and women living in Germany using data from a population-based nationwide cross-sectional study. 1,439 men and 1,486 women aged 18-64 participated in the German Health Interview and Examination Survey (2008-2011) and completed a standardized sub-maximal cycle ergometer test. Maximal oxygen consumption ([Formula: see text]) in ml·min-1·kg-1 was estimated. Mean values of VO2max for various anthropometric, behavioral, interpersonal, and sociodemographic variables were estimated. Linear regression analyses using multiple imputations technique for missing values was performed to analyze the influence of potential correlates on CRF. Women with high alcohol consumption had higher [Formula: see text], (ß = 2.20; 95% CI 0.98 to 3.42) than women with low alcohol consumption and women with high occupational status had higher [Formula: see text] (ß = 1.83; 95% CI 0.21 to 3.44) in comparison to women with low occupational status. Among men, high fruit intake (ß = 1.52; 95% CI 0.63 to 2.40), compared to low or medium fruit intake and performing at least 2.5 hours of total PA per week (ß = 2.19; 95% CI 1.11 to 3.28), compared to less than 2.5 hours was associated with higher [Formula: see text]. Among both men and women, lower body mass index, lower waist circumference and higher levels of physical exercise were considerably associated with higher [Formula: see text]. Among women, those in higher age groups showed a considerably lower level of [Formula: see text] compared with those aged 18-24. Furthermore, mean estimated [Formula: see text] was higher among men (36.5; 95% CI 36.0 to 37.0) than among women (30.3; 95% CI 29.8 to 30.7). Despite the cross-sectional nature of the current study, we conclude that several behavioral, anthropometric, and sociodemographic factors are associated with CRF in the general adult population in Germany. These results can provide evidence to tailor prevention measures according to the needs of specific subgroups.

Influencing factors of obesity in school-age children and adolescents - A systematic review of the literature in the context of obesity monitoring.

Around 15% of children and adolescents in Germany are overweight or obese. To support the planning, implementation and evaluation of preventive activities, the Robert Koch Institute (RKI) has developed a population-wide monitoring of influencing factors relevant to the development of obesity during childhood (AdiMon). AdiMon is a web-based indicator system providing population-wide meaningful and regularly updated data on factors that influence obesity in kindergarten-age girls and boys (0- to 6-years-old). Towards the end of 2020, the RKI will expand the indicator system to also cover the 7- to 17-year-old age group. To this end, a systematic review of the literature was conducted, a process which served to identify over 80 relevant factors that influence the development of obesity. These factors have been attributed to the categories behaviour, environment, biology, pre- and postnatal, psychosocial factors and context. Compared to a previous literature review for kindergarten-age children, around one tenth of the influencing factors now identified are new, including 'peer group influences' and 'bullying'. As the results highlight, an array of influencing factors must be considered when expanding the monitoring system, ranging from individual health behaviour to the social framework conditions and environmental factors.

Health behaviour and COVID-19: Initial findings on the pandemic.

The COVID-19 pandemic poses new challenges to both individuals and societies that impact health behaviour in many ways. This narrative review brings together initial findings for smoking, alcohol use, nutrition, physical activity and obesity. Smoking and obesity are potential direct risk factors for a severe course of COVID-19, and alcohol abuse, physical inactivity and an unbalanced diet can be indirect risk factors. The constraints of public life to contain the COVID-19 pandemic reduced the opportunities for physical activity and sports, although the initial results on physical activity during this period for Germany do not reflect this assumption. While a part of the population reports making healthier diet choices than before the pandemic, others do not. For smoking and risky alcohol use, data at an aggregate level for the general population do not indicate any behaviour changes. However, different trends appear to be emerging for different population groups pointing to the fact that social inequalities in pandemic-related changes to health behaviour must be assumed. Should further studies confirm these results, this would indicate a need for pandemic-specific prevention measures. Furthermore, specifically during the pandemic, prevention and health promotion measures directed at changes to health behaviour should continue to be implemented and adapted to the restrictions due to the pandemic. Equity in health should be promoted in particular.

Risky Alcohol Consumption and Heavy Episodic Drinking among Parents in Germany: Results of a Nationwide Cross-Sectional Study.

Introduction: Risky alcohol consumption (RAC) and heavy episodic drinking (HED) by parents can have negative effects on their children. At present, little is known about these forms of alcohol consumption among parents in Germany. The aim of this analysis is to estimate the percentage of parents living in Germany who practise RAC and HED and to study associations between these consumption patterns and sociodemographic factors. Material and Methods: The data basis comprises the data of the nationwide studies "Gesundheit in Deutschland aktuell" (GEDA) of 2009, 2010, and 2012. The data were collected by means of computer-assisted telephone interviews (CATI). Our analysis included all participants living in a household with at least one child of their own under 18 years of age (n = 16,224). Information on RAC and HED was collected using the AUDIT-C screening instrument. Logistic regression models were used to study the relationship between parental alcohol consumption and sociodemographic variables. Results: 18.4% of the mothers and 29.6% of the fathers exhibited RAC; 8.4% of the mothers and 21.0% of the fathers practised HED. After mutual adjustment, RAC showed a significant association with the level of education, income (only mothers), employment status (only mothers), migration background, relationship status (only mothers), and the age of the youngest child. HED showed a significant association with income (only mothers), the age of the youngest child (only mothers), and the level of education (only fathers). Conclusions: The presented analysis emphasizes the relevance of preventive measures to reduce parental alcohol consumption. In addition to universal interventions, risk group-specific measures (e.g., for parents with high income) are needed to reduce parental alcohol consumption and thus support a healthy development of children.

Correlates and Determinants of Cardiorespiratory Fitness in Adults: a Systematic Review.

BACKGROUND: Enhanced cardiorespiratory fitness (CRF) is now a well-established predictor of numerous adverse health outcomes. Knowledge about the pathways leading to enhanced CRF is essential for developing appropriate interventions. Hence, the aim of this review was to provide a detailed overview of the current state of research regarding individual factors associated with or influencing CRF among the general adult population. METHODS: We searched the PubMed, EMBASE, and Cochrane Library databases and also conducted a search for grey literature (Google Scholar). Eligible indicators of CRF were objectively assessed measures of CRF by submaximal or maximal exercise testing measured using treadmill or cycle ergometer tests. We included quantitative observational studies of the general adult population. Using a semi-quantitative approach, we compiled summary tables aggregating the study results for each potential correlate or determinant of CRF. RESULTS: We identified 3005 studies, 78 of which met the inclusion criteria. Almost all of these studies were conducted in high-income countries. Study quality scores assessing the risk of bias in the individual studies ranged from 40 to 100%. Male sex, age (inverse), education, socioeconomic status, ethnicity, body mass index (inverse), body weight (inverse), waist circumference, body fat (inverse), resting heart rate (inverse), C-reactive protein (inverse), smoking (inverse), alcohol consumption, and multiple measures of leisure-time physical activity were independently and consistently associated with CRF. CONCLUSIONS: In synthesizing the current research on the correlates and determinants of CRF among adults, this systematic review identified gaps in the current understanding of factors influencing CRF. Beyond the scope of this review, environmental and interpersonal determinants should be further investigated. SYSTEMATIC REVIEW REGISTRATION: PROSPERO, CRD42017055456.

Quantum gas microscopy of Rydberg macrodimers.

The subnanoscale size of typical diatomic molecules hinders direct optical access to their constituents. Rydberg macrodimers-bound states of two highly excited Rydberg atoms-feature interatomic distances easily exceeding optical wavelengths. We report the direct microscopic observation and detailed characterization of such molecules in a gas of ultracold rubidium atoms in an optical lattice. The bond length of about 0.7 micrometers, comparable to the size of small bacteria, matches the diagonal distance of the lattice. By exciting pairs in the initial two-dimensional atom array, we resolved more than 50 vibrational resonances. Using our spatially resolved detection, we observed the macrodimers by correlated atom loss and demonstrated control of the molecular alignment by the choice of the vibrational state. Our results allow for rigorous testing of Rydberg interaction potentials and highlight the potential of quantum gas microscopy for molecular physics.

Health inequalities among children and adolescents in Germany. Developments over time and trends from the KiGGS study.

This study examines the extent to which health inequalities among children and adolescents in Germany have developed over the past decade. The analyses are based on data from the German Health Interview and Examination Survey for Children and Adolescents (KiGGS), which are representative of the 0- to 17-year-old population in Germany. The KiGGS data were collected in three waves: the KiGGS baseline study (2003-2006), KiGGS Wave 1 (2009-2012) and KiGGS Wave 2 (2014-2017). Prevalences of five health outcomes are considered: general health, mental health problems, physical activity, the consumption of sugary soft drinks, and smoking. Moreover, it defines health inequalities in relation to differences in the socioeconomic status of the family (SES), an index derived from the parents' level of education, occupation and income, and considers both absolute and relative health inequalities. In order to do so, the Slope Index of Inequality (SII) and the Relative Index of Inequality (RII) were calculated using linear probability or log-binomial models. Significant inequalities were identified to the detriment of young people from families with a low SES. These inequalities were particularly pronounced in the KiGGS Wave 2 data with regard to general health and the consumption of sugary soft drinks. Additionally, evidence from trend analyses for these two outcomes suggests that relative inequalities have increased. However, absolute inequalities decreased during the same period, and this also applies to smoking. The persistently high and, in some cases, widened levels of health inequalities indicate that adolescents from families with a low SES do not benefit to the same extent from disease prevention and health promotion measures for children and adolescents as young people from families with a higher SES.

Educational differences in the prevalence of behavioural risk factors in Germany and the EU - Results from the European Health Interview Survey (EHIS) 2.

This article examines educational differences in the prevalence of behavioural risk factors among adults and compares the results for Germany with the average from the European Union (EU). Data were derived from the second wave of the European Health Interview Survey, which took place between 2013 and 2015 (EHIS 2). Analyses were conducted using a regression-based calculation of relative and absolute educational differences in the prevalence of behavioural risk factors, based on self-reported data from women and men aged between 25 and 69 (n=217,215). Current smoking, obesity, physical activity lasting less than 150 minutes per week, heavy episodic drinking and non-daily fruit or vegetable intake are more prevalent among people with a low education level than those with a high education level. This applies to Germany as well as the EU average. Overall, the relative educational differences identified for these risk factors place Germany in the mid-range compared to the EU average. However, relative educational differences in current smoking and heavy episodic drinking are more manifest among women in Germany than the EU average, with the same applying to low physical activity among men. In contrast, relative educational differences in non-daily fruit or vegetable intake are less pronounced among women and men in Germany than the average across the EU. Increased efforts are needed in various policy fields to improve the structural conditions underlying health behaviour, particularly for socially disadvantaged groups, and increase health equity.

[Time trends of occupational differences in smoking behaviour of employed men and women in Germany : Results of the 1999-2013 microcensus]. / Zeitliche Entwicklung berufsgruppenspezifischer Unterschiede im Rauchverhalten von erwerbstätigen Männern und Frauen in Deutschland : Ergebnisse des Mikrozensus 1999­2013.

BACKGROUND: Studies show that people with a low occupational status are more likely to smoke than those with a high occupational status. Against the background of a general decline in tobacco consumption, time trends of occupational differences in smoking behaviour of employed men and women in Germany were examined. METHODS: The analyses were based on the last five waves of the German microcensus that included questions about smoking (1999, 2003, 2005, 2009 and 2013), taking only employed men and women aged 18-64 years into account (n = 688,746). Information on occupational position was summarised using international classifications of occupation (ISEI-08 and ISCO-08). Raw and model-based standardized prevalence estimates of current smoking were calculated. RESULTS: Between 1999 and 2013, the proportion of smokers in the working population fell from 39.9 to 34.4% (men) and from 30.6 to 26.8% (women). Differences between occupational status groups increased significantly: while the prevalence of smoking among employees with high occupational status decreased, it remained largely stable in the low status group. In 2013, the occupations with the highest proportion of smokers were waste disposal workers, cleaning staff, unskilled workers, truck and bus drivers, salespeople and cashiers, and employees in the catering industry. CONCLUSION: Since the beginning of the 2000s, the prevalence of smoking in the working population has declined. The strengthened tobacco control policy - e. g. the establishment of smoke-free workplace laws - might have contributed to this trend. In the context of workplace health promotion, tobacco prevention and cessation measures should be targeted at those professions in which smoking is still particularly common.

[Trends in smoking among adults in Germany : Evidence from seven population-based health surveys from 1991-2015]. / Zeitliche Trends beim Rauchverhalten Erwachsener in Deutschland : Ergebnisse sieben bundesweiter Gesundheitssurveys 1991­2015.

BACKGROUND: Despite decreasing smoking prevalence, tobacco use remains a key public health problem in Germany. For planning, managing, and evaluating tobacco control measures, regular data collection on smoking behavior in the population is essential. The aim of this article is to present trends in adult tobacco use since the early 1990s based on data from the health monitoring of the Robert Koch-Institute (RKI). METHODS: Analyses are based on data from 106,158 individuals aged 18 to 79 years, who participated in seven RKI health surveys from 1991-2015. Trends in tobacco consumption were analyzed using different indicators of smoking behavior, stratified by age, cohort, and gender. RESULTS: An overall falling smoking prevalence can be attributed primarily to a significant decline in the younger age groups since the early 2000s. Trend analysis by cohort reveals a declining prevalence for almost all cohorts over time from 1991-2015. Historically there has been is a sharp increase in the prevalence of women who have ever smoked between the 1930-1934 and 1950-1959 cohorts. The proportion of men who have ever smoked slightly decreased between the 1930-1934 and 1980-1984 cohorts. DISCUSSION: The shown overall decline happened concurrently with various tobacco prevention measures implemented during this period in Germany. If present trends related to continuous high smoking rates are sustained, it can be assumed that the tobacco consumption of the population will remain the source of adverse health outcomes. Accordingly, tobacco prevention measures and the promotion of smoking cessation in all age groups should be a public health priority.

Socioeconomic Correlates and Determinants of Cardiorespiratory Fitness in the General Adult Population: a Systematic Review and Meta-Analysis.

BACKGROUND: This review aims to (1) consolidate evidence regarding the association between socioeconomic status (SES) and cardiorespiratory fitness (CRF), (2) conduct a meta-analysis of the association between SES and CRF using methodologically comparable data, stratified by sex, and (3) test whether the association varies after adjustment for physical activity (PA). METHODS: A systematic review of studies from MEDLINE, EMBASE, Latin American and Caribbean Health Sciences (LILACS), Scientific Electronic Library Online (ScIELO), and Cochrane Library without time or language restrictions, which investigated associations between SES and CRF. Risk of bias within studies was assessed using a customized quality assessment tool. Results were summarized in table format and methodologically similar studies were synthesized using meta-analysis of Hedges' g effect sizes. Synthesized results were appraised for cross-study bias. Results were tested for the impact of PA adjustment using meta-regression. RESULTS: Compared to individuals with low education, both men and women showed higher CRF among individuals with high education (men 0.12 [0.04-0.20], women 0.19 [0.02-0.36]), while participants with medium education showed no significant difference in CRF (men 0.03 [- 0.04-0.11], women 0.09 [- 0.03-0.21]). Adjustment for PA did not significantly impact the association between education and CRF. CONCLUSIONS: There is fair evidence for an association between high levels of education and increased CRF. This could have implications for monitoring, of health target compliance and of chronic disease risk among higher risk populations, to detect and prevent non-communicable diseases (NCDs) and to diminish social health inequalities. TRIAL REGISTRATION: PROSPERO, CRD42017055456.