Gymnastik- och idrottshögskolan, GIH

BACKGROUND: Healthy lifestyle habits are recommended in prevention of cardiovascular disease (CVD). However, there is limited knowledge concerning the change in lifestyle-related factors from before to after a CVD event. Thus, this study aimed to explore if and how lifestyle habits and other lifestyle-related factors changed between two health assessments in individuals experiencing a CVD event between the assessments, and if changes varied between subgroups of sex, age, educational level, duration from CVD event to second assessment and type of CVD event.

METHODS: Among 115,504 Swedish employees with data from two assessments of occupational health screenings between 1992 and 2020, a total of 637 individuals (74% men, mean age 47 ± SD 9 years) were identified having had a CVD event (ischemic heart disease, cardiac arrythmia or stroke) between the assessments. Cases were matched with controls without an event between assessments from the same database (ratio 1:3, matching with replacement) by sex, age, and time between assessment (n = 1911 controls). Lifestyle habits included smoking, active commuting, exercise, diet, alcohol intake, and were self-rated. Lifestyle-related factors included overall stress, overall health (both self-rated), physical capacity (estimated by submaximal cycling), body mass index and resting blood pressure. Differences in lifestyle habits and lifestyle-related factors between cases and controls, and changes over time, were analysed with parametric and non-parametric tests. Multiple logistic regression, OR (95% CI) was used to analyse differences in change between subgroups.

RESULTS: Cases had, in general, a higher prevalence of unhealthy lifestyle habits as well as negative life-style related factors prior to the event compared to controls. Nevertheless, cases improved their lifestyle habits and lifestyle factors to a higher degree than controls, especially their amount of active commuting (p = 0.025), exercise (p = 0.009) and non-smoking (p < 0.001). However, BMI and overall health deteriorated to a greater extent (p < 0.001) among cases, while physical capacity (p < 0.001) decreased in both groups.

CONCLUSION: The results indicate that a CVD event may increase motivation to improve lifestyle habits. Nonetheless, the prevalence of unhealthy lifestyle habits was still high, emphasizing the need to improve implementation of primary and secondary CVD prevention.

Background: Quantification of movement intensity and energy utilization, together with frequency of trips, duration, distance, step counts and cadence, is essential for interpreting the character of habitual walking for transport, and its potential support of health. The purpose of the study is to illuminate this with valid methods and novel perspectives, and to thereby provide a new basis for characterizing and interpreting walking in relation to health outcomes.

Methods: Habitual middle-aged commuting pedestrians (males = 10, females= 10) were investigated in the laboratory at rest and with maximal treadmill and cycle ergometer tests. Thereafter, levels of oxygen uptake, energy expenditure, ventilation, heart rate, blood lactate, rated perceived exertion, cadence, number of steps, duration, distance, and speed were recorded during the normal walking commute of each participant in Greater Stockholm, Sweden. The number of commutes per week over the year was self-reported.

Results: Walking in the field demanded about 30% more energy per km compared to level treadmill walking. For both sexes, the walking intensity in field was about 46% of maximal oxygen uptake, and energy expenditure amounted to 0.96 kcal · kg−1 · km−1. The MET values (males: 6.2; females:6.5) mirrored similar levels of walking speed (males: 5.7; females: 5.9 km · h−1) and levels of oxygen uptake (males: 18.6; females: 19.5mL · kg−1 · min−1). The average number of MET-hours per week in a typical month was 22 for males and 20 for females. This resulted in a total weekly energy expenditure of∼1,570 and 1,040 kcal for males and females, respectively. Over the year, the number of walking commutes and their accumulated distance was ∼385 tripsand 800 km for both sexes.

Conclusion: Walking in naturalistic field settings demands its own studies. When males and females walk to work, their relative aerobic intensities and absolute energy demands for a given distance are similar. It is equivalent to the lower part of the moderate relative intensity domain.The combination of oxygen uptake, trip duration and frequency leads to high and sustained levels of MET-hours as well as energy expenditure per week over the year, with a clear health enhancing potential. Based on this study we recommend 6000 transport steps per day, or equivalent, during five weekdays, over the year, in order to reach optimal health gains.

BACKGROUND: The impact of cardiorespiratory fitness (CRF) and other lifestyle-related factors on severe COVID-19 risk is understudied. The present study aims to investigate lifestyle-related and socioeconomic factors as possible predictors of COVID-19, with special focus on CRF, and to further study whether these factors may attenuate obesity- and hypertension-related risks, as well as mediate associations between socioeconomic factors and severe COVID-19 risk.

METHODS: Out of initially 407,131 participants who participated in nationwide occupational health service screening between 1992 and 2020, n = 857 cases (70% men, mean age 49.9 years) of severe COVID-19 were identified. CRF was estimated using a sub-maximum cycle test, and other lifestyle variables were self-reported. Analyses were performed including both unmatched, n = 278,598, and sex-and age-matched, n = 3426, controls. Severe COVID-19 included hospitalization, intensive care or death due to COVID-19.

RESULTS: Patients with more severe COVID-19 had significantly lower CRF, higher BMI, a greater presence of comorbidities and were more often daily smokers. In matched analyses, there was a graded decrease in odds for severe COVID-19 with each ml in CRF (OR = 0.98, 95% CI 0.970 to 0.998), and a two-fold increase in odds between the lowest and highest (< 32 vs. ≥ 46 ml·min^-1·kg^-1) CRF group. Higher BMI (per unit increase, OR = 1.09, 1.06 to 1.12), larger waist circumference (per cm, OR = 1.04, 1.02 to 1.06), daily smoking (OR = 0.60, 0.41 to 0.89) and high overall stress (OR = 1.36, 1.001 to 1.84) also remained significantly associated with severe COVID-19 risk. Obesity- and blood pressure-related risks were attenuated by adjustment for CRF and lifestyle variables. Mediation through CRF, BMI and smoking accounted for 9% to 54% of the associations between low education, low income and blue collar/low skilled occupations and severe COVID-19 risk. The results were consistent using either matched or unmatched controls.

CONCLUSIONS: Both lifestyle-related and socioeconomic factors were associated with risk of severe COVID-19. However, higher CRF attenuated the risk associated with obesity and high blood pressure, and mediated the risk associated with various socioeconomic factors. This emphasises the importance of interventions to maintain or increase CRF in the general population to strengthen the resilience to severe COVID-19, especially in high-risk individuals.

Purpose: Quantifying intensities of physical activities through measuring oxygen uptake (V̇O₂) is of importance for understanding the relation between human movement, health and performance. This can in principle be estimated by the heart rate (HR) method, based on the linear relationship between HR and V̇O₂ established in the laboratory. It needs, however, to be explored whether HR methods, based on HR-V̇O₂ relationships determined in the laboratory, are valid for estimating spectrums of V̇O₂ in field exercise. We hereby initiate such studies, and use cycle commuting as the form of exercise.

Methods: Ten male and ten female commuter cyclists underwent measurements of HR and V̇O₂ while performing ergometer cycling in a laboratory and a normal cycle commute in the metropolitan area of Stockholm County, Sweden. Two models of individual HR-V̇O₂ relationships were established in the laboratory through linear regression equations. Model 1 included three submaximal work rates, whereas model 2 also involved a maximal work rate. The HR-V̇O₂ regression equations of the two models were then used to estimate V̇O₂ at six positions of field HR: five means of quintiles and the mean of the whole commute. The estimations obtained were for both models compared with the measured V̇O₂.

Results: The measured quintile range during commuting cycling was about 45-80% of V̇O₂max. Overall, there was a high resemblance between the estimated and measured V̇O₂, without any significant absolute differences in either males or females (range of all differences: -0.03-0.20 L⋅min^-1). Simultaneously, rather large individual differences were noted.

Conclusion: The present HR methods are valid at group level for estimating V̇O₂ of cycle commuting characterized by relatively wide spectrums of exercise intensities. To further the understanding of the external validity of the HR method, there is a need for studying other forms of field exercises.

The COVID-19 pandemic has become a public health emergency of international concern, which may have affected lifestyle habits and mental health. Based on national health profile assessments, this study investigated perceived changes of lifestyle habits in response to the COVID-19 pandemic and associations between perceived lifestyle changes and mental health in Swedish working adults. Among 5599 individuals (50% women, 46.3 years), the majority reported no change (sitting 77%, daily physical activity 71%, exercise 69%, diet 87%, alcohol 90%, and smoking 97%) due to the pandemic. Changes were more pronounced during the first wave (April–June) compared to the second (October–December). Women, individuals &lt;60 years, those with a university degree, white-collar workers, and those with unhealthy lifestyle habits at baseline had higher odds of changing lifestyle habits compared to their counterparts. Negative changes in lifestyle habits and more time in a mentally passive state sitting at home were associated with higher odds of mental ill-health (including health anxiety regarding one’s own and relatives’ health, generalized anxiety and depression symptoms, and concerns regarding employment and economy). The results emphasize the need to support healthy lifestyle habits to strengthen the resilience in vulnerable groups of individuals to future viral pandemics and prevent health inequalities in society.

Objective: To evaluate and compare ratio and allometric scaling models of maximal oxygen consumption (VO₂max) for different body size measurements in relation to cardiovascular disease (CVD) incidence and all-cause mortality.

Methods: 316 116 individuals participating in occupational health screenings, initially free from CVD, were included. VO₂max was estimated using submaximal cycle test. Height, body mass and waist circumference (WC) were assessed, and eight different scaling models (two evaluated in a restricted sample with WC data) were derived. Participants were followed in national registers for first-time CVD event or all-cause mortality from their health screening to first CVD event, death or 31 December 2015.

Results: Increasing deciles of VO₂max showed lower CVD risk and all-cause mortality for all six models in the full sample (p<0.001) as well as with increasing quintiles in the restricted sample (eight models) (p<0.001). For CVD risk and all-cause mortality, significantly weaker associations with increasing deciles for models 1 (L·min^-1) and 5 (mL·min^-1·height^-2) were seen compared with model 2 (mL·min^-1·kg^-1), (CVD, p<0.00001; p<0.00001: all-cause mortality, p=0.008; p=0.001) and in some subgroups. For CVD, model 6 (mL·min^-1·(kg¹·height^-1)^-1) had a stronger association compared with model 2 (p<0.00001) and in some subgroups.In the restricted sample, trends for significantly stronger associations for models including WC compared with model 2 were seen in women for both CVD and all-cause mortality, and those under 50 for CVD.

Conclusion: In association to CVD and all-cause mortality, only small differences were found between ratio scaling and allometric scaling models where body dimensions were added, with some stronger associations when adding WC in the models.

BACKGROUND: Total sitting time is associated with a higher risk for cardio metabolic disease and mortality, while breaks in prolonged sitting attenuate these effects. However, less is known about associations of different specific domains and breaks of sitting on general health, back/neck pain and if physical activity could influence these associations. The aim was to investigate how workplace sitting and frequency of breaking up workplace sitting is associated with self-reported general health and self-reported back/neck pain.

METHODS: 44,978 participants (42% women) from the Swedish working population, who participated in a nationwide occupational health service screening 2014-2019, were included in this cross-sectional study. Self-reported sitting duration and frequency of breaks from sitting at work, general health, back/neck pain, exercise, leisure time sitting, diet, smoking, stress and body mass index were assessed. Occupation was classified as requiring higher education qualifications or not. Logistic regression modelling was used to assess the association between workplace sitting/frequency of breaks in workplace sitting and poor general health and back/neck pain, respectively.

RESULTS: Compared to sitting all the time at work, sitting ≤75% of the time showed significantly lower risks for poor general health (OR range 0.50-0.65), and sitting between 25 and 75% of the time showed significantly lower risks (OR 0.82-0.87) for often reported back/neck pain. For participants reporting sitting half of their working time or more, breaking up workplace sitting occasionally or more often showed significantly lower OR than seldom breaking up workplace sitting; OR ranged 0.40-0.50 for poor health and 0.74-0.81 for back/neck pain.

CONCLUSIONS: Sitting almost all the time at work and not taking breaks is associated with an increased risk for self-reported poor general health and back/neck pain. People sitting almost all their time at work are recommended to take breaks from prolonged sitting, exercise regularly and decrease their leisure time sitting to reduce the risk for poor health.

BACKGROUND: Trend analyses of active commuting and potential variations in trends and association with cardiovascular disease (CVD) risk within sub-groups are unknown.

OBJECTIVES: To a) describe trends in active commuting between 1998 to 2015 and b) to study the association between different amounts of active commuting and the incidence risk of CVD in a large sample of Swedish workers, and analyses of potential variations across sub-groups of socio-demographics, physical activity and BMI.

METHODS: A total of 318,309 participants (47% women, 18-74 years) who participated in a nationwide occupational health service screening between 1998 and 2015 were included. Commuting habits were self-reported, and data on first-time CVD events were derived from national registers.

RESULTS: Self-reported passive commuters decreased between 1998 and 2015 (64% to 56%), transferring to an increase in mainly moderate/high-dose active commuters (12% to 19%). Changes were seen in all subgroups. The characteristics and life-style habits of the typical passive and active commuter changed little over the study period. Low- and moderate/high-dose active commuters had significantly decreased risks for a first time CVD during follow-up. This was accentuated in men, middle-aged and in participants with light physical work situations, irregular exercise habits, being overweight/obese and with low fitness.

CONCLUSION: Increases in active commuting were observed between 1998 and 2015, however still leaving a majority who do not actively commute. As active commuting, regardless dose, is associated with a lower CVD risk, encouraging more people to actively commute may provide an easily accessible and time-efficient possibility to increase physical activity and health in the general population.

Introduction. The heart rate (HR) method is a promising approach for evaluating oxygen uptake (V̇O₂), energy demands and exercise intensities in different forms of physical activities. It would be valuable if the HR method, established on ergometer cycling, is interchangeable with other regular activities, such as level walking. This study therefore aimed to examine the interchangeability of the HR method when estimating V̇O₂ for ergometer cycling and level treadmill walking in submaximal conditions. 

Methods. Two models of HR-V̇O₂ regression equations for cycle ergometer exercise (CEE) and treadmill exercise (TE) were established with 34 active commuters. Model 1 consisted of three submaximal intensities of ergometer cycling or level walking, model 2 included also one additional workload of maximal ergometer cycling or running. The regression equations were used for estimating V̇O₂ with seven individual HR values based on 25-85% of HR reserve (HRR). The V̇O₂ estimations were compared between CEE and TE, within and between each model.

Results. Only minor, and in most cases non-significant, average differences were observed when comparing the estimated V̇O₂ levels between CEE and TE. Model 1 ranged from -0.4 to 4.8% (n.s.) between 25-85 %HRR. In model 2, the differences between 25-65 %HRR ranged from 1.3 to -2.7% (n.s.). At the two highest intensities, 75 and 85 %HRR, V̇O₂ was slightly lower (3.7%, 4.4%; P < 0.05), for CEE than TE. The inclusion of maximal exercise in the HR-V̇O₂ relationships reduced the individual V̇O₂ variations between the two exercise modalities.

Conclusion. The HR methods, based on submaximal ergometer cycling and level walking, are interchangeable for estimating mean V̇O₂ levels between 25-85% of HRR. Essentially, the same applies when adding maximal exercise in the HR-V̇O₂ relationships. The inter-individual V̇O₂ variation between ergometer cycling and treadmill exercise is reduced when using the HR method based on both submaximal and maximal workloads.