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

Cardiorespiratory fitness and muscular fitness correlates in youth: A hierarchy of behavioral, contextual, and health-related outcomes

OBJECTIVES

Despite the health importance of identifying correlates of physical fitness in youth, no investigation to date has explored the influence of behavioral, health-related, and contextual correlates simultaneously. We investigated the hierarchical relationship of multiple modifiable correlates favoring or diminishing cardiorespiratory and muscular fitness in youth.

DESIGN

Cross-sectional investigation.

METHODS

In a sample of 5174 children and adolescents, 31 correlates were hierarchized according to their impact on cardiorespiratory and muscular fitness assessed using the FITESCOLA® fitness battery. A Chi-squared Automatic Interaction Detection approach was employed and measures of correlation and association were used to investigate the relationship between physical fitness and correlates.

RESULTS

In children, body mass index was the most relevant factor to discriminate between high and low cardiorespiratory and muscular fitness of the upper, middle, and lower body. While body mass index was more important than any other correlate to differentiate levels of upper and lower body muscular fitness during adolescence, specific characteristics of sports participation emerged as key factors to discriminate between high and low cardiorespiratory fitness and middle body muscular fitness. Other correlates, including the self-report of active recess time, active commuting to school, favorable neighborhood conditions, and limited time on screens and cellphones, were demonstrative of favorable physical fitness levels.

CONCLUSIONS

Both body composition and sports-related characteristics emerged as the two most relevant factors of physical fitness in youth. Additional health benefits may be obtained from building supportive environments for sports and healthy exercise habits within the household and at different school education levels.

Estimating cardiorespiratory fitness in older adults using the international physical activity questionnaire

Introduction

Non-exercise estimates of cardiorespiratory fitness hold great utility for epidemiological research and clinical practice. Older adults may yield the greatest benefit from fitness estimates due to limited capacity to undergo strenuous maximal exercise testing, however, few of the previously developed non-exercise equations are suitable for use in older adults. Thus, the current study developed a non-exercise equation for estimating cardiorespiratory fitness in older adults derived from the widely used International Physical Activity Questionnaire (IPAQ).

Methods

This study was a secondary analysis of baseline data from a randomized controlled trial. Participants were community-dwelling, cognitively unimpaired older adults aged 60-80 years (n = 92). They completed the IPAQ and underwent maximal exercise testing on a cycle ergometer. Stepwise linear regression was used to determine the equation in a randomly selected, sex-balanced, derivation subset of participants (n = 60), and subsequently validated using a second subset of participants (n = 32).

Results

The final equation included age, sex, body mass index and leisure time activity from the IPAQ and explained 61% and 55% of the variance in the derivation and validation groups, respectively (standard error of estimates = 3.9, 4.0). Seventy-seven and 81% of the sample fell within ±1SD (5.96 and 6.28 ml·kg-1·min-1) of measured VO2peak for the derivation and validation subgroups. The current equation showed better performance compared to equations from Wier et al. (2006), Jackson et al. (1990), and Schembre & Riebe (2011), although it is acknowledged previous equations were developed for different populations.

Conclusions

Using non-exercise, easily accessible measures can yield acceptable estimates of cardiorespiratory fitness in older adults, which should be further validated in other samples and examined in relation to public health outcomes.

Lower motor performance is linked with poor sleep quality, depressive symptoms, and grey matter volume alterations

Motor performance (MP) is essential for functional independence and well-being, particularly in later life. However, the relationship between behavioural aspects such as sleep quality and depressive symptoms, which contribute to MP, and the underlying structural brain substrates of their interplay remains unclear. This study used three population-based cohorts of younger and older adults (n=1,950) from the Human Connectome Project-Young Adult (HCP-YA), HCP-Aging (HCP-A), and enhanced Nathan Kline Institute-Rockland sample (eNKI-RS). Several canonical correlation analyses were computed within a machine learning framework to assess the associations between each of the three domains (sleep quality, depressive symptoms, grey matter volume (GMV)) and MP. The HCP-YA analyses showed progressively stronger associations between MP and each domain: depressive symptoms (unexpectedly positive, r=0.13, SD=0.06), sleep quality (r=0.17, SD=0.05), and GMV (r=0.19, SD=0.06). Combining sleep and depressive symptoms significantly improved the canonical correlations (r=0.25, SD=0.05), while the addition of GMV exhibited no further increase (r=0.23, SD=0.06). In young adults, better sleep quality, mild depressive symptoms, and GMV of several brain regions were associated with better MP. This was conceptually replicated in young adults from the eNKI-RS cohort. In HCP-Aging, better sleep quality, fewer depressive symptoms, and increased GMV were associated with MP. Robust multivariate associations were observed between sleep quality, depressive symptoms and GMV with MP, as well as age-related variations in these factors. Future studies should further explore these associations and consider interventions targeting sleep and mental health to test the potential effects on MP across the lifespan.

Reference values for estimated VO2max by two submaximal cycle tests: the Åstrand-test and the Ekblom-Bak test

AIMS

Submaximal tests estimating VO2max have inherent biases; hence, using VO2max estimations from the same test is essential for reducing this bias. This study aimed to establish sex- and age-specific reference values for estimated VO2max using the Åstrand-test (Å-test) and the Ekblom-Bak test (EB-test). We also assessed the effects of age, exercise level, and BMI on VO2max estimations.

METHODS

We included men and women (20-69 years) from the Swedish working population participating in Health Profile Assessments between 2010 and 2020. Excluding those on heart rate-affecting medicines and smokers, n = 263,374 for the Å-test and n = 95,043 for the EB-test were included. VO2max reference values were based on percentiles 10, 25, 40, 60, 75, and 90 for both sexes across 5-year age groups.

RESULTS

Estimated absolute and relative VO2max were for men 3.11 L/min and 36.9 mL/min/kg using the Å-test, and 3.58 L/min and 42.4 mL/min/kg using the EB-test. For women, estimated absolute and relative VO2max were 2.48 L/min and 36.6 mL/min/kg using the Å-test, and 2.41 L/min and 35.5 mL/min/kg using the EB-test. Higher age (negative), higher exercise level (positive), and higher BMI (negative) were associated with estimated VO2max using both tests. However, explained variance by exercise on estimated VO2max was low, 10% for the Å-test and 8% for the EB-test, and moderate for BMI, 23% and 29%.

CONCLUSION

We present reference values for estimated VO2max from two submaximal cycle tests. Age, exercise, and BMI influenced estimated VO2max. These references can be valuable in clinical evaluations using the same submaximal tests.

Cardiorespiratory fitness, perceived fitness and autonomic function in in-patients with different depression severity compared with healthy controls

Over 300 million individuals worldwide suffer from major depressive disorder (MDD). Individuals with MDD are less physically active than healthy people which results in lower cardiorespiratory fitness (CRF) and less favorable perceived fitness compared with healthy controls. Additionally, individuals with MDD may show autonomic system dysfunction. The purpose of the present study was to evaluate the CRF, perceived fitness and autonomic function in in-patients with MDD of different severity compared with healthy controls. We used data from 212 in-patients (age: 40.7 ± 12.6 y, 53% female) with MDD and from 141 healthy controls (age: 36.7 ± 12.7 y, 58% female). We assessed CRF with the Åstrand-Rhyming test, self-reported perceived fitness and autonomic function by heart rate variability (HRV). In specific, we used resting heart rate, time- and frequency-based parameters for HRV. In-patients completed the Beck Depression Inventory-II (BDI-II) to self-assess the subjectively rated severity of depression. Based on these scores, participants were grouped into mild, moderate and severe MDD. The main finding was an inverse association between depression severity and CRF as well as perceived fitness compared with healthy controls. Resting heart rate was elevated with increasing depression severity. The time-based but not the frequency-based autonomic function parameters showed an inverse association with depression severity. The pattern of results suggests that among in-patients with major depressive disorder, those with particularly high self-assessed severity scores show a lower CRF, less favorable perceived fitness and partial autonomic dysfunction compared to healthy controls. To counteract these conditions, physical activity interventions may be effective.

Estimated Cardiorespiratory Fitness and Metabolic Risks

This review focuses on the emerging evidence for the association between non-exercise fitness testing, estimated cardiorespiratory fitness (eCRF), and metabolic risk factors. Given the challenges associated with directly measuring cardiorespiratory fitness (CRF) in large populations, eCRF presents a practical alternative for predicting metabolic health risks. A literature search identified seven relevant cohort studies from 2020 to 2024 that investigated the association of eCRF with hypertension, hyperglycemia, dyslipidemia, and obesity. This review consistently demonstrates an inverse relationship between higher eCRF and a lower incidence of metabolic risks, which is in line with CRF cohort studies. It highlights the importance of low eCRF as a primordial indicator for metabolic risks and underscores the potential for broader application. Future research directions should include exploring eCRF's predictive ability across diverse populations and health outcomes and testing its real-world applicability in healthcare and public health settings.

Measuring Cardiorespiratory Fitness without Exercise Testing: The Development and Validation of a New Tool for Spanish Adults

Background: Cardiorespiratory fitness (CRF) is an important component of overall physical fitness and is associated with numerous health benefits, including a reduced risk of heart disease, diabetes, and obesity. However, direct measurement of CRF is time-consuming and therefore not feasible for screening purposes. Methods: A maximal treadmill exercise test with the Bruce protocol was performed to estimate VO2max in 1047 Spanish men and women aged 17 to 62 years. Weight, height, and heart rate were measured. Leisure-time physical activity (LTPA) was recorded using the Minnesota Leisure Time Physical Activity Questionnaire. A multiple linear regression model was developed to predict exercise-based VO2max. The validity of the model was examined by correlation, concordance, Bland-Altman analysis, cross-validation, and construct validity analysis. Results: There was no significant difference between VO2max obtained by the Bruce protocol (43.56 mL/kg/min) or predicted by the equation (43.59 mL/kg/min), with R2 of 0.57, and a standard error of the estimate of 7.59 mL/kg/min. Pearson's product-moment correlation and Lin's concordance correlation between measured and predicted CRF values were 0.75 and 0.72, respectively. Bland-Altman analysis revealed a significant proportional bias of non-exercise eCRF, overestimating unfit and underestimating highly fit individuals. However, 64.3% of participants were correctly classified into CRF tertile categories, with an important 69.9% in the unfit category. Conclusions: The eCRF equation was associated with several cardiovascular risk factors in the anticipated directions, indicating good construct validity. In conclusion, the non-exercise eCRF showed a reasonable validity to estimate true VO2max, and it may be a useful tool for screening CRF.

Changes in physical fitness and body build of women and men surveyed in 2004 and 2022-A longitudinal study

Physical fitness plays a crucial role in determining human health and overall well-being. The objective of the study was to assess the changes in body structure and physical fitness among individuals examined in 2004 and 2022 (persons aged 32-34 and 50-52). The research material consists of data from the Krakow Continuous Study (KCS) of somatic development and physical fitness of people born in 1970 and 1972, conducted in Krakow in the years 1976-2022. In total, in 2004, 103 women and 122 men took part in the study, and in 2022-47 women and 67 men. Of these participants, 37 women and 53 men were present for both measurements. The following measurements were performed-physical fitness tests: handgrip strength of left and right hand, standing broad jump, sit-and-reach test and overhead medicine ball throw (2 kg); anthropometric measurements: body height, body weight and tissue composition, circumferences of the chest (relaxed and in deep inspiration), waist, hips, thigh, mid-upper-arm (MUAC, relaxed and in deep inspiration), forearm and calf, thickness of biceps, triceps, subscapular, abdominal, suprailiac and calf skinfolds; width of shoulders and hips, depth and width of the chest. A comparative analysis of the two series showed that all fitness test scores deteriorated. The percentage decrease was greater in women than in men in the tests of right and left handgrip strength and overhead medicine ball throw than in men, in the standing broad jump test similar in both sexes, in the sit-and-reach test-lower in women than in men. The greatest decreases were observed in the standing broad jump (by 14%) and the 2 kg medicine ball throw (15-12%), both in women and men. In contrast, the level of development of most of the somatic characteristics studied in 2022 was higher compared to the previous study, and, apart from body height, elbow and knee width and calf skinfold in both sexes, the differences in arithmetic means between the 2004 and 2022 series were statistically significant. Furthermore, the absence of involutionary changes in body height can be highlighted. In conclusion, the decrease in physical fitness occurring in adulthood and the increase in most somatic characteristics between 32 and 34 year-olds and 50 and 52 year-olds were confirmed.

Cardiorespiratory responses: Pilates compared to different walking speeds in healthy adults

BACKGROUND

The impact of a single-session Pilates exercise on cardiorespiratory fitness and metabolic parameters is still uncertain.

AIMS

The aim of this study was to examine the cardiorespiratory changes during a single-session Pilates exercise and compare cardiorespiratory fitness-related parameters with walking at different speeds on a treadmill, at low (3.2 kph) and moderate intensities (4.8 kph).

METHODS

Cardiorespiratory responses were measured with a cardiopulmonary exercise test device in 31 healthy young adults at rest, during a single Pilates session, walking at 3.2 kph and walking at 4.8 kph. The study design employed a cross-over design. Participants were randomly assigned to two experimental groups: a Pilates training session following treadmill walking or treadmill walking following a Pilates training session.

RESULTS

Mean MET, oxygen and energy consumption during Pilates were similar to walking at 3.2 kph (p > 0.05), but significantly lower than walking at 4.8 kph (p < 0.05). The mean heart rate during Pilates was higher than walking at 3.2 kph (p < 0.05), but similar to walking at 4.8 kph (p > 0.05). Significantly higher carbohydrate metabolism was used during Pilates compared to walking (p < 0.05).

CONCLUSION

The cardiopulmonary responses to a single Pilates session are similar to walking at a speed of 3.2 kph but lower than walking at 4.8 kph. These results indicate that while Pilates may not generate sufficient cardiopulmonary changes to enhance cardiorespiratory fitness as a moderate-intensity exercise in healthy young adults, it may still offer other benefits such as improvements in flexibility, core strength, and posture.

Mediation analysis of the associations between neighbourhood walkability and greenness, accelerometer-measured physical activity, and health-related fitness in urban dwelling Canadians

OBJECTIVE

To estimate sex-specific associations (total, direct, and indirect effects) between objectively measured neighbourhood walkability and greenness and objectively measured physical activity and health-related fitness including cardiorespiratory and muscular fitness in Canadian adults.

METHODS

Neighbourhood walkability (Canadian Active Living Environment) and greenness (Normalized Difference Vegetation Index; NDVI) data were linked to cardiorespiratory (i.e., submaximal step test estimated V̇O2 max) and muscular fitness (i.e., handgrip strength) and accelerometer measured physical activity; Canadian Health Measures Survey). Covariate-adjusted sex-stratified path analyses was conducted to assess if physical activity (light: LPA; moderate: MPA, and; vigorous: VPA) mediated the associations between neighbourhood walkability, NDVI and health-related fitness. Model sample sizes ranged from 987 to 2796 for males and 989 to 2835 for females.

RESULTS

Among males, we found indirect effects between neighbourhood walkability and cardiorespiratory fitness via LPA (negative) and VPA (positive). We also found a total effect (negative) between neighbourhood walkability and grip strength and indirect effects between neighbourhood walkability and handgrip strength via LPA (negative) and MPA (negative). Among females, we found a total effect (positive) and direct effect (positive) between neighbourhood walkability and cardiorespiratory fitness, and an indirect effect for neighbourhood walkability and cardiorespiratory fitness via LPA. We found no significant effects related to neighbourhood greenness.

CONCLUSIONS

Residing in a neighbourhood with higher walkability may positively affect cardiorespiratory fitness but negatively affect muscular strength. The negative associations between neighbourhood walkability and LPA may offset potential positive associations between neighbourhood walkability and MPA and VPA and their subsequent influence on health-related fitness.

Moderating effect of cardiorespiratory fitness on sickness absence in occupational groups with different physical workloads

Sickness absence from work has a large adverse impact on both individuals and societies in Sweden and the costs for sickness absence were calculated to 64.6 billion Swedish kronor (approx. 5.6 billion in Euros) in 2020. Although high cardiorespiratory fitness may protect against potential adverse effects of high physical workload, research on the moderating effect of respiratory fitness in the relation between having an occupation with high physical workload and sickness absence is scarce. To study the moderating effect of cardiorespiratory fitness in the association between occupation and psychiatric, musculoskeletal, and cardiorespiratory diagnoses. Data was retrieved from the HPI Health Profile Institute database (1988-2020) and Included 77,366 participants (mean age 41.8 years, 52.5% women) from the Swedish workforce. The sample was chosen based on occupational groups with a generally low education level and differences in physical workload. Hurdle models were used to account for incident sickness absence and the rate of sickness absence days. There were differences in sickness absence between occupational groups for musculoskeletal and cardiorespiratory diagnoses, but not for psychiatric diagnoses. In general, the association between occupation and musculoskeletal and cardiorespiratory diagnoses was moderated by cardiorespiratory fitness in most occupational groups with higher physical workload, whereas no moderating effect was observed for psychiatric diagnoses. The study results encourage community and workplace interventions to both consider variation in physical workload and to maintain and/or improve cardiorespiratory fitness for a lower risk of sickness absence, especially in occupations with high physical workload.

Independent and joint associations of cardiorespiratory fitness and BMI with dementia risk: the Cooper Center Longitudinal Study

OBJECTIVE

This study aimed to examine the association of midlife fitness and body mass index (BMI) with incident dementia later in life.

DESIGN AND PARTICIPANTS

A cohort study of 6428 individuals (mean age 50.9±7.6 years) from the Cooper Center Longitudinal Study.

MEASURES

Cardiorespiratory fitness and BMI were assessed twice (1970-1999) during visits to the Cooper Clinic, a preventive medicine clinic in Dallas, Texas. These measures were examined as continuous and categorical variables. As continuous variables, fitness and BMI were examined at baseline (averaged of two examinations) and as absolute change between exams (mean time 2.1±1.8 years). Variables were categorised: unfit versus fit and normal versus overweight/obese. Medicare claims data were used to obtain all-cause dementia incidence (1999-2009). Mean follow-up between midlife examinations and Medicare surveillance was 15.7 ((SD=6.2) years. Multivariable models were used to assess the associations between fitness, BMI and dementia.

RESULTS

During 40 773 person years of Medicare surveillance, 632 cases of dementia were identified. After controlling for BMI and covariates, each 1-metabolic equivalent increment in fitness was associated with 5% lower (HR 0.95; 95% CI 0.90 to 0.99) dementia risk. In comparison, after controlling for fitness and covariates, each 1 kg/m2 increment in BMI was associated with a 3.0% (HR 1.03; 95% CI 1.00 to 1.07) higher risk for dementia, yet without significance (p=0.051). Similar findings were observed when the exposures were categorised. Changes in fitness and BMI between examinations were not related to dementia. Jointly, participants who were unfit and overweight/obese had the highest (HR 2.28 95% CI 1.57 to 3.32) dementia risk compared with their fit and normal weight counterparts.

CONCLUSION

Lower midlife fitness is a risk marker for dementia irrespective of weight status. Being unfit coupled with overweight/obese status might increase one's risk for dementia even further.

Assessment of Cardiorespiratory Fitness in 8-to-15-Year-Old Children with Overweight/Obesity by Three-Minute Step Test: Association with Degree of Obesity, Blood Pressure, and Insulin Resistance

OBJECTIVE

To assess cardiorespiratory fitness in children and adolescents with overweight/obesity using the Kasch pulse recovery (KPR) test, and its correlation with severity of obesity, insulin resistance, and blood pressure (BP).

METHODS

This is a retrospective analysis of baseline data from a study evaluating the efficacy of yoga for reduction of body mass index (BMI) in children aged 8-15 y with overweight/obesity. KPR three-minute step test was done. Children were classified into cardiorespiratory fitness categories based on the post-KPR heart rate (HR); the maximal oxygen consumption (VO2 max) was calculated, and the correlation analysis was done.

RESULTS

One hundred fifty-five children with mean age of 11.6 ± 1.8 y and mean BMI of 26.2 ± 4.1 kg/m2 were included. Mean post-KPR-HR and calculated VO2 max were 119 ± 14 per minute and 48.7 ± 5.6 mL/kg/min, respectively. In children < 13 y, cardiorespiratory fitness was excellent or very good in 28%, good or sufficient in 58%, and poor or very poor in 14%. BMI, waist circumference (WC), resting HR, systolic BP, and homeostatic model of insulin resistance (HOMA-IR) were higher among those with poor/very poor fitness, with WC z score being statistically significant (p = 0.015). Post-KPR-HR showed positive correlation with BMI z score (r = 0.16, p = 0.044), WC z score (r = 0.21, p = 0.011), and HOMA-IR (r = 0.22, p = 0.012).

CONCLUSION

In children with overweight/obesity, 14% had poor cardiorespiratory fitness. Post-KPR-HR and calculated VO2 max had good correlation with measures of obesity and HOMA-IR. Further studies evaluating cardiorespiratory fitness and normative data of VO2 max for Indian children are warranted.

Usual-Paced 400m Long Distance Corridor Walk Estimates Cardiorespiratory Fitness among Older Adults: The Study of Muscle, Mobility and Aging (SOMMA)

Background

Cardiopulmonary exercise testing (CPET), the gold-standard method to quantify cardiorespiratory fitness (CRF), is not always feasible due to cost, access, and burden. The usual-paced 400m long-distance corridor walk (LDCW), a measure of mobility among older adults, may provide an alternate method to assess CRF among populations unable to complete maximal intensity testing. The purpose of this study was to develop and validate an estimating equation to estimate VO 2 peak from average 400m walking speed (WS) among participants in the Study of Muscle, Mobility and Aging (SOMMA).

Methods

At baseline, participants (N=820, 76.2±4.9 years, 58% Women, 86% Non-Hispanic White) completed a 400m LDCW (400m WS=400m/completion time in seconds) and symptom-limited maximal CPET (Modified Balke Protocol). VO 2 peak (mL/kg/min) was considered the highest 30-second average oxygen consumption during CPET. Other covariates included: age, sex, race, physical activity (7-day wrist-worn accelerometer), physical function (Short Physical Performance Battery, range 0-12), perceived physical fatigability (Pittsburgh Fatigability Scale, range 0-50), and Borg Rating of Perceived Exertion (RPE, range 6-20) at completion of the 400m LDCW. Stepwise linear regression was used. Internal validation was completed using data-splitting method (70%; 30%).

Results

Mean VO 2 peak was 20.2±4.8 mL/kg/min and mean 400m WS was 1.06±0.2 m/s. Each 0.05 m/s increment in 400m WS was associated with a 0.40 mL/kg/min higher VO 2 peak after adjustment for covariates. An estimating equation including 400m WS, age, sex, race, and RPE was developed. Internal validation showed low overall bias (-0.26) and strong correlation (r = 0.71) between predicted and measured VO 2 peak values. Bland-Altman plot and regression analyses indicated predicted VO 2 peak was an acceptable alternative, despite mean underestimation of 4.53 mL/kg/min among those with CPET VO 2 peak ≥25 mL/kg/min.

Conclusions

Usual-paced 400m LDCW strongly correlates with direct measures of cardiorespiratory fitness during CPET in older adults with lower fitness and can be used to test both fitness and function.

Obesity, Cardiorespiratory Fitness, and Cardiovascular Disease

PURPOSE OF REVIEW

Obesity, generally defined by body mass index (BMI), is an established risk factor for the development of cardiovascular disease (CVD), while cardiorespiratory fitness (CRF) decreases risk. In chronic CVD, an obesity survival paradox in which higher BMI is associated with improved prognosis has been reported. This paper will examine the effect of obesity on CVD risk, explore obesity as a risk factor in patients with established CVD, and investigate the relationship between CRF, obesity, and CVD.

RECENT FINDINGS

Through metabolic and hemodynamic changes, obesity increases the risk for CVD and contributes to the development of other cardiovascular risk factors such as diabetes, dyslipidemia, and hypertension. Obesity is associated with metabolic, hormonal, and inflammatory changes that leads to atherosclerosis increasing the risk for coronary artery disease, and myocardial remodeling increasing the risk for heart failure. However, it has also been observed that overweight/obese patients with established CVD have a better prognosis when compared to non-obese individuals termed the obesity paradox. CRF is a vital component of health associated with improved cardiovascular outcomes and furthermore has been shown to markedly attenuate or nullify the relationship between obesity and CVD risk/prognosis. Increasing CRF mitigates CVD risk factors and improves overall prognosis in CVD regardless of obesity status.

Cardiorespiratory fitness components in relation to clinical characteristics, disease state and medication intake: A patient registry study

BACKGROUND

Interpretation of cardiopulmonary exercise testing (CPET) results requires thorough understanding of test confounders such as anthropometrics, comorbidities and medication. Here, we comprehensively assessed the clinical determinants of cardiorespiratory fitness and its components in a heterogeneous patient sample.

METHODS

We retrospectively collected medical and CPET data from 2320 patients (48.2% females) referred for cycle ergometry at the University Hospital Leuven, Belgium. We assessed clinical determinants of peak CPET indexes of cardiorespiratory fitness (CRF) and its hemodynamic and ventilatory components using stepwise regression and quantified multivariable-adjusted differences in indexes between cases and references.

RESULTS

Lower peak load and peak O2 uptake were related to: higher age, female sex, lower body height and weight, and higher heart rate; to the intake of beta blockers, analgesics, thyroid hormone replacement and benzodiazepines; and to diabetes mellitus, chronic kidney disease, non-ST elevation myocardial infarction and atrial fibrillation (p < 0.05 for all). Lower peak load also correlated with obstructive pulmonary diseases. Stepwise regression revealed associations of hemodynamic and ventilatory indexes (including heart rate, O2 pulse, systolic blood pressure and ventilation at peak exercise and ventilatory efficiency) with age, sex, body composition and aforementioned diseases and medications. Multivariable-adjusted differences in CPET metrics between cases and controls confirmed the associations observed.

CONCLUSION

We described known and novel associations of CRF components with demographics, anthropometrics, cardiometabolic and pulmonary diseases and medication intake in a large patient sample. The clinical implications of long-term noncardiovascular drug intake for CPET results require further investigation.

Associations between cardiorespiratory fitness in youth and the incidence of site-specific cancer in men: a cohort study with register linkage

OBJECTIVES

To assess the associations between cardiorespiratory fitness (CRF) in young men and the incidence of site-specific cancer.

METHODS

A Swedish population-based cohort study with register linkage of men who underwent military conscription in 1968-2005 was undertaken. CRF was assessed by maximal aerobic workload cycle test at conscription. Cox regression models assessed linear associations and included CRF, age, year and site of conscription, body mass index and parental level of education. CRF was also categorised into low, moderate and high for facilitated interpretation and results comparing high and low CRF are reported.

RESULTS

Primary analyses were performed in 1 078 000 men, of whom 84 117 subsequently developed cancer in at least one site during a mean follow-up of 33 years. Higher CRF was linearly associated with a lower hazard ratio (HR) of developing cancer in the head and neck (n=2738, HR 0.81, 95% CI 0.74 to 0.90), oesophagus (n=689, HR 0.61, 95% CI 0.50 to 0.74), stomach (n=902, HR 0.79, 95% CI 0.67 to 0.94), pancreas (n=1280, HR 0.88, 95% CI 0.76 to 1.01), liver (n=1111, HR 0.60, 95% CI 0.51 to 0.71), colon (n=3222, HR 0.82, 95% CI 0.75 to 0.90), rectum (n=2337, HR 0.95, 95% CI 0.85 to 1.05), kidney (n=1753, HR 0.80, 95% CI 0.70 to 0.90) and lung (n=1635, HR 0.58, 95% CI 0.51 to 0.66). However, higher CRF predicted a higher hazard of being diagnosed with prostate cancer (n=14 232, HR 1.07, 95% CI 1.03 to 1.12) and malignant skin cancer (n=23 064, HR 1.31, 95% CI 1.27 to 1.36).

CONCLUSION

We report a number of protective associations between higher CRF in healthy young men and the subsequent hazard of site-specific cancers. These results have implications for public health policymaking, strengthening the incentive to promote health through improving CRF in youth.

What Can One Minute of the Day Tell about Physical Activity?

High cardiorespiratory fitness (CRF) allows individuals to perform daily activities and operate at a higher intensity level. This study investigates the connection between the CRF and peak intensity of physical activity (PA) in absolute and relative terms. A total of 3587 participants (1447 men, 51.9 ± 13.0 years; 2140 women, 50.0 ± 13.0 years) provided substantial accelerometer wear time, and their CRF was estimated via the 6 min walking test. Participants were divided into CRF thirds by age group and sex. Daily one-minute peak intensities were captured in both absolute terms and relative to individual CRF levels. In absolute terms, the highest CRF third had the highest intensity value for men (6.4 ± 1.7 MET; 5.9 ± 1.4 MET; 5.3 ± 1.0 MET) and for women (6.4 ± 1.6 MET; 5.9 ± 1.3 MET; 5.4 ± 1.1 MET). In relative terms, the highest CRF third utilized the least aerobic capacity for men (49 ± 14%; 51 ± 13%; 56 ± 14%) and for women (52 ± 13%; 54 ± 12%; 62 ± 15%). One minute of daily activity offers valuable insights into an individual's CRF and the effort demanded during PA. Fitter individuals can sustain higher PA intensity levels in absolute terms, whereas individuals with lower CRF utilize a greater fraction of their aerobic capacity. Consequently, heightened CRF not only allows for enhanced intensity levels but also safeguards against strenuous PA during daily routines.

Causal associations between cardiorespiratory fitness and type 2 diabetes

Higher cardiorespiratory fitness is associated with lower risk of type 2 diabetes. However, the causality of this relationship and the biological mechanisms that underlie it are unclear. Here, we examine genetic determinants of cardiorespiratory fitness in 450k European-ancestry individuals in UK Biobank, by leveraging the genetic overlap between fitness measured by an exercise test and resting heart rate. We identified 160 fitness-associated loci which we validated in an independent cohort, the Fenland study. Gene-based analyses prioritised candidate genes, such as CACNA1C, SCN10A, MYH11 and MYH6, that are enriched in biological processes related to cardiac muscle development and muscle contractility. In a Mendelian Randomisation framework, we demonstrate that higher genetically predicted fitness is causally associated with lower risk of type 2 diabetes independent of adiposity. Integration with proteomic data identified N-terminal pro B-type natriuretic peptide, hepatocyte growth factor-like protein and sex hormone-binding globulin as potential mediators of this relationship. Collectively, our findings provide insights into the biological mechanisms underpinning cardiorespiratory fitness and highlight the importance of improving fitness for diabetes prevention.

Association between cardiorespiratory fitness and low back pain is anxiety-dependent: A prospective cohort study among adults and older adults

To investigate the relationship between low back pain and cardiorespiratory fitness (CRF) among participants with and without self-report anxiety. Participants were 13,080 individuals (86.6% men; 44.7 ± 9.3 years). CRF was quantified as maximal treadmill test duration and was grouped for analysis as low (lowest 20% of treadmill test duration), moderate (middle 40%), and high (upper 40%). Cox regression analysis was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) between low back pain and CRF according to the presence/absence of self-report anxiety. During an average of 5.7 ± 5.1 years of follow-up, 2,965 cases of low back pain were identified. Participants with self-report anxiety and low CRF had 3.7 times (HR: 3.7; 95%CI: 1.7-8.2) more risk for having low back pain when compared with participants with self-report anxiety and high CRF. Additionally, among participants with self-reported anxiety, moderate CRF was associated with an 70% greater risk of having low back pain than those with high CRF (HR: 1.7; 95%CI: 1.1-3.2). For participants without self-reported anxiety, no association was found between the risk of having low back pain and CRF. According to the results identified in the present study, participants with self-reported anxiety who had low and moderate CRF had higher risks of low back pain than those with high CRF.

Lung function at 16-19 years in males and females born very prematurely

OBJECTIVES

To determine if there were differences in lung function at 16-19 years of age between males and females born very prematurely.

WORKING HYPOTHESIS

Females compared with males would have superior lung function and exercise capacity.

STUDY DESIGN

Cohort study.

PATIENT-SUBJECT SELECTION

Those born at less than 29 weeks of gestational age.

METHODOLOGY

Lung function testing (spirometry, oscillometry, diffusion capacity, lung clearance index, and plethysmography), a shuttle sprint test for exercise capacity, and a respiratory symptoms questionnaire.

RESULTS

Amongst 150 participants, males had poorer lung function compared with females with mean z score differences (95% CI [confidence interval]) after adjustment: forced expiratory flow at 75% (FEF₇₅ ) (-0.60 [-0.97,-0.24]), forced expiratory flow at 50% (FEF₅₀ ) (-0.39 [-0.72,-0.07]), forced expiratory flow at 25%-75% (FEF_25-75 ) (-0.62 [-0.98,-0.26]), the ratio of the forced expiratory volume in the first one second to the forced vital capacity of the lungs (FEV₁ :FVC ratio) (-0.71 [-1.09,-0.34]), diffusing capacity of the lungs for carbon monoxide (DLCO) (-0.41 [-0.78,-0.03]), diffusing capacity of the lung for carbon monoxide divided by alveolar volume (DLCO/VA) (-0.57 [-0.86,-0.28]). Exercise capacity and self-reported exercise were both significantly better in males than females (46% males achieving between 1250 and 1500 m shuttle sprint distance vs. 4.8% females) and 74% males versus 67% females undertaking some exercise. There were no significant differences by sex in the prevalence of either wheeze or current asthma.

CONCLUSIONS

Males had poorer lung function than females at age 16-19 years, but their exercise capacity was superior to females.

Associations between cardiovascular risk factors, disease activity and cardiorespiratory fitness in patients with inflammatory joint disease: a cross-sectional analysis

BACKGROUND

Inflammatory joint diseases (IJD) are accompanied by an increased risk of cardiovascular disease (CVD). Cardiorespiratory fitness (CRF) is a modifiable CVD risk factor and low levels of CRF associate with an elevated CVD risk. This study aimed to investigate the associations between CVD risk factors, disease activity and CRF in patients with IJD and to explore differences between patients with normal versus low levels of CRF.

METHODS

CRF was measured as peak oxygen uptake (VO_2peak) with a cardiopulmonary exercise test. Participants were also evaluated for: Body composition, blood pressure, blood lipids, inflammatory markers and disease activity. Patient-reported use of cigarettes/snuff, medication, disease duration, pain, fatigue, CVD history, habitual physical activity and exercise beliefs and self-efficacy were collected by questionnaire. Cross-sectional associations between CVD risk factors, disease-related factors and CRF were analyzed by multiple linear regression. CRF was categorized to normal CRF (VO_2peak ≥ 80%) or low CRF (VO_2peak < 80%) according to age- and gender-stratified reference data. Differences in demographic, CVD and disease-related factors between patients with normal versus low CRF were explored.

RESULTS

In 60 Norwegian patients with IJD [34 females, age 59 years (IQR: 52-63)], mean VO_2peak was 30.2 (± 6.9) mL/kg/min, corresponding to 83% (± 18) of normative reference values. Age (coefficient: - 0.18 years, p = 0.01) and fat mass (coefficient: - 0.67 %, p < 0.001) were inversely associated with CRF, while physical activity index (coefficient: 0.13 points, p = 0.05) was positively associated with CRF (R² = 0.66). There were no significant associations between CRF, classical CVD risk factors and disease-related variables. Compared to patients with low CRF (n = 30), patients with normal CRF (n = 30) had higher peak oxygen uptake (+ 9.4 mL/kg/min, p < 0.001), high-density lipoprotein cholesterol (+ 0.5 mmol L^-1, p < 0.001), and exercise self-efficacy (+ 6.9, p < 0.01) as well as lower fat mass (- 8.7%, p < 0.001), resting heart rate (- 8.0 beats/min, p < 0.01) and triglycerides (- 0.5 mmol L^-1, p < 0.01).

CONCLUSIONS

In this sample of IJD-patients, age, fatmass and physical activity level were associated with CRF. CRF was lower than reference values and patients with normal CRF presented with a more favorable health profile. There is a continued need for exercise interventions to improve CRF in patients with IJD.

TRIAL REGISTRATION

NCT04922840.

The association between rheumatoid arthritis and reduced estimated cardiorespiratory fitness is mediated by physical symptoms and negative emotions: a cross-sectional study

OBJECTIVES

Persons with rheumatoid arthritis (RA) have lower cardiorespiratory fitness (CRF) than healthy individuals. We sought to identify variables explaining the association between RA status and reduced CRF.

METHODS

RA patients recruited from two Norwegian hospitals and blood donors recruited as controls filled in questionnaires about physical activity, physical symptoms, and psychological factors. Estimated CRF (eCRF) was calculated from non-exercise models. The relationship between RA status and reduced eCRF was explored with structural equation modelling. The latent variables physical symptoms (based on morning stiffness, joint pain, and pain in neck, back, or hips) and negative emotions (based on Hospital Anxiety and Depression Scale's Depression score and Cohen's perceived stress scale) were included as possible mediators between RA status and eCRF in separate and combined models adjusted for age and sex.

RESULTS

Two-hundred-and-twenty-seven RA patients and 300 controls participated. The patients were older and had lower eCRF than controls (age- and sex-adjusted mean difference: 1.7 mL/kg/min, p=0.002). Both latent variables were significant mediators of the association between RA and reduced eCRF when included in separate models. The latent variables mediated 74% of the total effect of RA on eCRF in the combined model. Standardized coefficients: direct effect of RA -0.024 (p=0.46), indirect effect through physical symptoms -0.034 (p=0.051), and indirect effect through negative emotions -0.034 (p=0.039).

CONCLUSION

Both physical symptoms and negative emotions mediated the association between RA and reduced eCRF with similar effect sizes. To successfully increase CRF in RA patients, both physical and psychological factors should be addressed. Key Points • The RA patients in the present study had 1.7 mL/kg/min lower mean estimated cardiorespiratory fitness (CRF) compared to healthy controls. • Mediation analysis demonstrated that physical symptoms and negative emotions mediated 74% of the total negative effect of RA on estimated CRF in a combined, adjusted model. • This suggests that both physical and psychological factors should be addressed when supporting RA patients in improving their CRF.

Positive impacts of leisure-time physical activity on cardiorespiratory fitness, co-morbidity level, cardiovascular health and quality of life among midlife adults: a cross-sectional study of a Nigerian population

BACKGROUND

Regular physical activity (PA) improves general health and quality of life (QoL) of the general population. It is however not known if leisure-time PA (LTPA) behaviour will reduce co-morbidity and adiposity, and improve cardiorespiratory fitness and QoL in midlife men. This study explored the impacts of regular LTPA behaviour on co-morbidity, adiposity, cardiorespiratory fitness and QoL among male midlife sports club members in a Nigerian population.

METHODS

This cross-sectional study involved 174 age-matched male midlife adults: 87 engaging in LTPA (LTPA group) and 87 not engaging in LTPA (non-LTPA group). Information on age, body mass index (BMI), waist circumference (WC), maximal oxygen uptake (VO₂max)_, resting heart rate (RHR), QoL and co-morbidity level was collected using standardized procedures. Data were summarized using mean and standard deviation, and explored using frequency and proportion. Independent t-test, Chi Square and Mann-Whitney U test were employed to determine the impacts of LTPA at 0.05 significance level.

RESULTS

The LTPA group had lower co-morbidity score (p = 0.05) and RHR (p = 0.004), and higher QoL (p = 0.01) and VO₂max (p = 0.003) than non-LTPA group. While heart disease (χ² = 10.99; p = 0.01) and hypertension (χ² = 15.24; p = 0.004) severity levels were associated with LTPA behaviour, hypertension (p = 0.01) was the only co-morbid condition that had a significantly lower score in the LTPA group than in the non-LTPA group.

CONCLUSIONS

Regular LTPA improves cardiovascular health, physical work capacity and QoL in the sample of Nigerian mid-life men. Regular LTPA behaviour is recommended for cardiovascular health promotion, and improved physical work capacity and life satisfaction in midlife men.

Toward characterizing cardiovascular fitness using machine learning based on unobtrusive data

Cardiopulmonary exercise testing (CPET) is a non-invasive approach to measure the maximum oxygen uptake ([Formula: see text]), which is an index to assess cardiovascular fitness (CF). However, CPET is not available to all populations and cannot be obtained continuously. Thus, wearable sensors are associated with machine learning (ML) algorithms to investigate CF. Therefore, this study aimed to predict CF by using ML algorithms using data obtained by wearable technologies. For this purpose, 43 volunteers with different levels of aerobic power, who wore a wearable device to collect unobtrusive data for 7 days, were evaluated by CPET. Eleven inputs (sex, age, weight, height, and body mass index, breathing rate, minute ventilation, total hip acceleration, walking cadence, heart rate, and tidal volume) were used to predict the [Formula: see text] by support vector regression (SVR). Afterward, the SHapley Additive exPlanations (SHAP) method was used to explain their results. SVR was able to predict the CF, and the SHAP method showed that the inputs related to hemodynamic and anthropometric domains were the most important ones to predict the CF. Therefore, we conclude that the cardiovascular fitness can be predicted by wearable technologies associated with machine learning during unsupervised activities of daily living.

Biological and psychological predictors of heart rate patterns during physical activity

Objective

Latent class modeling (LCM) offers a promising approach for examining correlates of heart rate (HR) patterns over multiple exercise sessions. This research examined biological and psychological variables associated with different patterns of HR response to physical activity (PA).

Methods

In a three-arm randomized controlled trial (exercise video games vs. standard exercise vs. non-exercise control), HR was recorded during PA sessions over a 12-week period. LCM identified three patterns of HR during PA across 189 participants in active arms: 1) high HR across sessions with low variability within sessions, 2) linear increase in HR across sessions with low variability within sessions, and 3) high variability in HR across all sessions. Associations with biological (resting heart rate, blood pressure, BMI, age, cholesterol, triglycerides, HbA1c) and psychological (depression, motivations for PA, PA-induced feelings) predictors of latent class membership were iteratively tested.

Results

Psychological variables played as important a role in the final model as biological variables for predicting latent class membership. Few differences were found between LC1 and LC2, but LC3 differed from the other two groups in that participants were likelier to report that feel revitalized after PA (vs. LC1 and LC2), to be less motivated for PA (vs. LC1), reported greater depression (vs. LC1 and LC2), and were younger (vs. LC1).

Conclusions

These findings demonstrate the potential of LCM to identify biological and psychological factors associated with chronotropic responses to PA, and advance understanding of the role of psychological factors in chronotropic PA outcomes.

Factors Associated with Cardiorespiratory Fitness in Breast Cancer Survivors from the State of Santa Catarina, Brazil: Cross-Sectional Study

Introduction: Oxygen consumption (VO2) is indicative of cardiorespiratory fitness (CRF) and lower levels are related to a higher risk of total mortality among individuals with cancer whose therapy can have adverse consequences on the cardiovascular system. Objective: To examine the associations of patient-reported sociodemographic, clinical, anthropometric outcomes and functional variables with CRF in 69 women (55±10 years) and to identify whether walking is a predictor of peak VO2 variation in this population with breast cancer (BC). Method: Female BC survivors receiving hormone therapy after two types of surgery (breast-conserving and mastectomy) underwent a CRF test on a cycle ergometer to measure peak VO2. A questionnaire containing sociodemographic, clinical data, patient reported outcomes (PROs) (depressive symptoms, sleep quality, fatigue, body image) and self-reported walking and tests to measure body fat percentage, waist circumference, flexibility and shoulder range of motion (RoM) were performed. Results: Unemployment and retirement were associated with low CRF, as was the use of aromatase inhibitors instead of tamoxifen. Depressive symptoms, worse body image, greater waist circumference, less flexibility and shoulder RoM were also associated with low CRF. Walking duration, controlled for age and body mass index (BMI), is a 13% predictor of peak VO2 variance in this sample. Conclusion: These factors must be considered in understanding the CRF profile of BC survivors. As walking was a predictor of peak VO2 variance, it should be recommended as a type of physical activity for patients with BC using hormone therapy.

C-Reactive Protein Is Associated with Physical Fitness in Breast Cancer Survivors

Background: Physical fitness (PF) is an expression of the physiological functioning of multiple body components. PF is an important prognostic factor in terms of cardiovascular mortality, cancer mortality, and all-cause mortality. PF has been related to some biomarkers in the general population but not in breast cancer survivors (BCS). Purpose: To evaluate the effects of PF on biomarkers potentially related to physical activity (PA) in a sample of BCS. Methods: Cross-sectional study. A total of 84 BCS (mean age 54) who had finished their treatment were recruited. Different components of PF were evaluated, namely body composition (anthropometry), cardiorespiratory fitness (one-mile walk test), muscular (handgrip and sit-to-stand timed test), and motor (gait speed) components. Sexual hormones, inflammation, and insulin resistance biomarkers were measured. Results: C-Reactive Protein (CRP) was associated with every component of physical fitness: cardiorespiratory fitness (p-value = 0.002), muscular (sit-to-stand timed test, p-value = 0.002) and motor (gait speed, p-value = 0.004) components, and body composition (body mass index, p-value = 0.003; waist, p-value < 0.000; and waist-to-hip index, p-value = 0.012). CRP also was associated with “poor physical condition,” a constructed variable that encompasses all components of physical fitness (p-value < 0.001). Insulin was associated with cardiorespiratory fitness and gait speed (p-values = 0.002 and 0.024, respectively). Insulin-like Growth Factor-1 was negatively associated with waist perimeter and waist-to-hip ratio. Conclusions: CRP can also be considered an indicator of poor PF in BCS. Implications for cancer survivors: in case of elevation of CRP indicating cardiovascular risk, health professionals should recommend lifestyle changes to improve BCS physical condition.

Correlates of cardiorespiratory fitness in a population-based sample of middle-aged adults: cross-sectional analyses in the SCAPIS study

OBJECTIVES

This study aimed to identify main sex-specific correlates of cardiorespiratory fitness (CRF) in a population-based, urban sample of Swedish adults.

DESIGN

Cross-sectional.

SETTING

Multi-site study at university hospitals, data from the Gothenburg site.

PARTICIPANTS

A total of 5308 participants (51% women, aged 50-64 years) with a valid estimated VO₂max, from submaximal cycle test, in the Swedish CArdioPulmonary bioImage Study (SCAPIS), were included.

PRIMARY AND SECONDARY OUTCOMES

A wide range of correlates were examined including (a) sociodemographic and lifestyle behaviours, (b) perceived health, anthropometrics and chronic conditions and (c) self-reported as well as accelerometer-derived physical activity and sedentary behaviours. Both continuous levels of estimated VO₂max as well as odds ratios (OR) and confidence intervals (CI)s of low VO₂max (lowest sex-specific tertile) were reported.

RESULTS

In multivariable regression analyses, higher age, being born abroad, short education, high waist circumference, poor perceived health, high accelerometer-derived time in sedentary and low in vigorous physical activity, as well as being passive commuter, correlated independently and significantly with low VO₂max in both men and women (OR range 1.31-9.58). Additionally in men, financial strain and being an ex-smoker are associated with higher odds for low VO₂max (OR 2.15; 95% CI 1.33 to 3.48 and OR 1.40; 95% CI 1.09 to 1.80), while constant stress with lower odds (OR 0.61; 95% CI 0.43 to 0.85). Additionally in women, being a regular smoker is associated with lower odds for low VO₂max (OR 0.64; 95% CI 0.45 to 0.92).

CONCLUSIONS

The present study provides important reference material on CRF and correlates of CRF in a general middle-aged population, which can be valuable for future research, clinical practice and public health work. If relations are causal, increased knowledge about specific subgroups will aid in the development of appropriate, targeted interventions.

Effect of psychosocial motivations and technology on physical activity behaviours among community older men and women

BACKGROUND

Implementation of physical activity strategies in older populations may be influenced by underlying psychosocial and gender-based factors to physical activity. We explored associations between these factors and physical activity behaviors and technology among older men and women.

METHODS

Community older adults underwent echocardiography and interviewer administered questionnaires that collected physical activity habits, self-motivation, self-empowerment and smartphone usage patterns associated with physical activity. Aerobic capacity was denoted by VO₂max (High VO₂ was defined as VO₂ > 35 (ml/kg/min) for men or VO₂ > 27 (ml/kg/min) for women).

RESULTS

Among 180 participants (mean age 77 (71-80) years; 43% females), 101 (56.1%) had a low VO₂max. Barriers to activity were lack of time (27.8%), tiredness (26.7%), affordability (12.8%) and pain while exercising (12.2%). Compared to participants with high VO₂max, those with low VO₂max were less likely to report feeling good post-exercise (70.3% vs 86.1%, adjusted p = 0.041) and express barriers to exercise (72.3% vs 88.6%, adjusted p = 0.017). Compared to men, women were more likely to express motivation for exercise if they were guided by an instructor (20.5% vs 1.96%, adjusted p = 0.027), less likely to prefer control over exercise type and difficulty (57.7% vs 82.4%, adjusted p = 0.001), express interest in smartphone apps (7.84% vs 24.4%, adjusted p = 0.01) and participate in apps-guided exercise (10.3% vs 29.4%, adjusted p = 0.001). Major factors that motivated the use of smartphone applications to manage individual health were financial incentives (23.9%) and guidance on exercise routines (21.1%) while the reveal of personal information was a major deterrent (28.3%).

CONCLUSIONS

We observed differences in physical activity motivation, empowerment and technology use based on gender and functional status. Tailoring physical activity strategies, including digital health strategies, that target psychosocial and gender-based factors may improve activity participation in older adults.

Relationship between Specific Field-Based Physical Fitness Test Results and Selected Health Biomarkers in College-Aged Males: A Cross-Sectional Study

OBJECTIVE

This study aimed to verify the association between specific field-based physical fitness test results and selected health biomarkers in college-aged males.

METHOD

A total of 390 males participated in this research. The association between fitness test scores and anthropometric and health variables were examined. The fitness tests conducted were: Sit-and-reach test (S&R), standing long jump test (SLJ), Shuttle run test (SHR), and 20 m Multistage Fitness Test (BT) to estimate the maximum oxygen uptake (VO2max). The anthropometric and health variables assessed were: Weight (WE), height (HE), body mass index (BMI), body fat percentage (FAT), lean body mass (LBM), abdominal Girth (AG), waist-to-hip ratio (WHR), systolic blood pressure (SBP), diastolic blood pressure (DBP), oxygen saturation (SPO2), average blood pressure (A-BP), double product (DP), and fasting blood glucose (GLU).

RESULTS

S&R presented a weak significant correlation with SLJ, VO2max, and AG. SLJ maintained weak to moderate significant correlations with S&R, SHR, VO2max, HE, WE, LBM, WHR, BMI, FAT, AG, SBP, DBP, A-BP, DP, and GLU. SHR presented weak to moderate significant correlations with SLJ, VO2max, WE, BMI, AG, FAT, HE, SBP, DP, and GLU. VO2max maintained weak to moderate correlations with S&R, SLJ, SHR, WE, BMI, FAT, LBM, AG, and DP. Weak to moderate correlations were found between anthropometric and health variables, whereas the anthropometric variables presented significant correlations with each other, ranging from weak to very strong. Fitness test results presented weak to moderate correlations among themselves.

CONCLUSION

SLJ and SHR present weak to moderate validity to predict the selected anthropometric markers and weak to predict the selected health indicators except for SPO2. VO2max has only weak validity to predict the selected anthropometric markers, whereas S&R is not valid to predict the selected health or anthropometric markers. Anthropometric measurements have weak validity in predicting the selected health markers. BMI and AG are valid, simple, and economical measurements to assess body fat. A positive interaction between the results obtained in the field-based fitness tests conducted was observed.

30 Year Trends of Reduced Physical Fitness in Undergraduate Students Studying Human Movement

The physical fitness of Canadian adults has decreased over the past 30 years, while sedentary time has increased. However, it is unknown if university students studying human movement exhibit similar population declines. Physical fitness (i.e., anthropometrics, musculoskeletal fitness, and aerobic fitness) and habitual activity (e.g., physical activity, stationary time, etc.) was measured in a cohort of kinesiology students (Post30; 2010-2016; n = 129 males, 224 females) using standardized fitness testing and accelerometry, respectively. Physical fitness was compared to data collected on a cohort of students from the same institution and program, 30 years prior (i.e., Pre, 1984-1987, n = 103 males, 73 females). Post30 had greater waist circumference (males: 83.6 ± 9.1 cm vs. 77.8 ± 8.3 cm, females: 77.1 ± 9.7 cm vs. 70.3 ± 5.2 cm, both p < 0.001) and lower estimated maximal aerobic fitness (males: 55 ± 11 vs. 63 ± 7, females: 45 ± 10 vs. 50 ± 7 mLO₂/kg/min, both, p < 0.001). Compared to Pre, male Post30 vertical jump (53.6 ± 10.2 vs. 57.0 ± 8.4 cm, p = 0.04) and female Post30 broad jump (178.7 ± 22.1 vs. 186.0 ± 15.5 cm, p < 0.001) were lower. A subsample (n = 65) of Post30 whose habitual activity was assessed, met the aerobic portion of Canadian physical activity guidelines (~400 min/week), but spent excessive amounts of time stationary (10.7 h/day). Current kinesiology students may not be immune to population decreases in physical fitness. Relative to previous group of students interested in movement, fitness was lower in our sample, potentially attributed to excessive stationary time. Regular assessment of physical fitness in kinesiology curriculums may be valuable to understand these declining trends in undergraduate students that mimic population declines in fitness.

The Relative Importance of Age at Peak Height Velocity and Fat Mass Index in High-Intensity Interval Training Effect on Cardiorespiratory Fitness in Adolescents: A Randomized Controlled Trial

Background: This study aimed to evaluate the role of biological age in the relationship between preintervention fat mass and cardiorespiratory fitness effects (CRF) after High-Intensity Interval Training (HIIT) intervention in adolescents. Methods: A total of 141 boys and girls (16 years) were examined as control (CG) and experimental (EG) groups that conducted a 10-week HIIT implemented in physical education. Measurements: body height, body weight, fat mass index (FMI), CRF (Harvard Step Test). Predicted age at peak height velocity (APHV) was calculated. Pathway analyses were conducted to identify the influences of the measured variables. Results: APHV harmed the level of ΔFI (fitness index) (β = −0.270; p = 0.035), while HIIT had a positive effect on changes in ΔFI (β = 0.246; p = 0.002). Sex affected the changes in CRF (β = 0.344; p = 0.011). Two models were designed respective to sex. The effect of the APHV on ΔFI in girls was close to significant (p = 0.053) but was non-significant in boys (p = 0.311). Changes in CRF in girls were positively and close to significance (p < 0.100) affected by FMIbaseline. Conclusion: HIIT is an effective way of exerting positive changes in CRF in adolescents, which is greater in boys than girls. APHV plays a role only in girls. The HIIT should be tailored to girls depending on their maturity status.

Habitual sedentary time and stationary time are inversely related to aerobic fitness

A one metabolic-equivalent-of-task increase in peak aerobic fitness (peak MET) is associated with a clinically relevant improvement in survival risk and all-cause mortality. The co-dependent impact of free-living physical behaviours on aerobic fitness are poorly understood. The purpose of this study was to investigate the impact of theoretically re-allocating time spent in physical behaviours on aerobic fitness. We hypothesized that substituting sedentary time with any physical activity (at any intensity) would be associated with a predicted improvement in aerobic fitness. Peak volume rate of oxygen uptake ( V ˙ O₂peak) was assessed via indirect calorimetry during a progressive, maximal cycle ergometer protocol in 103 adults (52 females; [38 ± 21] years; [25.0 ± 3.8] kg/m²; V ˙ O₂peak: [35.4 ± 11.5] ml·kg^-1·min^-1). Habitual sedentary time, standing time, light- (LPA), moderate- (MPA), and vigorous-physical activity (VPA) were assessed 24-h/day via thigh-worn inclinometry for up to one week (average: [6.3 ± 0.9] days). Isotemporal substitution modelling examined the impact of replacing one physical behaviour with another. Sedentary time (β = -0.8, 95% CI: [-1.3, -0.2]) and standing time (β = -0.9, 95%CI: [-1.6, -0.2]) were negatively associated with V ˙ O₂peak, whereas VPA was positively associated with relative V ˙ O₂peak (β = 9.2, 95%CI: [0.9, 17.6]). Substituting 30-min/day of VPA with any other behaviour was associated with a 2.4-3.4 higher peak MET. Higher standing time was associated with a lower aerobic fitness. As little as 10-min/day of VPA predicted a clinically relevant 0.8-1.1 peak MET increase. Theoretically, replacing any time with relatively small amounts of VPA is associated with improvements in aerobic fitness.

COX7A2L genetic variants determine cardiorespiratory fitness in mice and human

Mitochondrial respiratory complexes form superassembled structures called supercomplexes. COX7A2L is a supercomplex-specific assembly factor in mammals, although its implication for supercomplex formation and cellular metabolism remains controversial. Here we identify a role for COX7A2L for mitochondrial supercomplex formation in humans. By using human cis-expression quantitative trait loci data, we highlight genetic variants in the COX7A2L gene that affect its skeletal muscle expression specifically. The most significant cis-expression quantitative trait locus is a 10-bp insertion in the COX7A2L 3' untranslated region that increases messenger RNA stability and expression. Human myotubes harboring this insertion have more supercomplexes and increased respiration. Notably, increased COX7A2L expression in the muscle is associated with lower body fat and improved cardiorespiratory fitness in humans. Accordingly, specific reconstitution of Cox7a2l expression in C57BL/6J mice leads to higher maximal oxygen consumption, increased lean mass and increased energy expenditure. Furthermore, Cox7a2l expression in mice is induced specifically in the muscle upon exercise. These findings elucidate the genetic basis of mitochondrial supercomplex formation and function in humans and show that COX7A2L plays an important role in cardiorespiratory fitness, which could have broad therapeutic implications in reducing cardiovascular mortality.

Cardiometabolic determinants of cardiorespiratory fitness at rest, during exercise and post-exercise periods

We aimed to assess the relationship between cardiorepiratory fitness (CRF) and cardiometabolic parameters among young Nigerian adults. 100 young adults (50 males, 50 females) aged 20-30 years, selected from College of Health Sciences, Nnamdi Azikiwe University, Nigeria, participated in the study. Subjects’ demographic data and medical information were obtained through the use of structured pre-exercise health and lifestyle screening questionnaire, physical examination and morphometric measurements. Exercise test was carried out using a mechanically braked magnetic ergometer bicycle at an incremental workload of 30 W every 2 min until the subject reached a volitional exhaustion. Blood pressure (BP) and heart rate (HR) were measured at rest, during exercise and at post-exercise periods. Data indicated a significantly (Ρ<0.05) lower resting HR and rate pressure product (RPP), but higher targeted HR reserve, %RPP increase, peak oxygen pulse, cardiac output, exercise duration and work rate compared with the intermediate and unfit groups in both sexes. Age and BMI adjusted correlation test also indicated significant associations between peak oxygen consumption (VO2) and resting HR, resting RPP, targeted HR reserve, oxygen pulse, cardiac output, % RPP increase, actual HR reserve, exercise duration, and work rate. In contrast, resting BP, resting pulse pressure, peak systolic blood pressure (SBP), peak HR, percentage maximum HR, SBP recovery and HR recovery did not correlate with peak VO2. The present findings suggest that a multiple approach involving both metabolic and cardiovascular interventions might be appropriate when implementing strategies to enhance CRF and improve general well-being.

Reference Standards for Cardiorespiratory Fitness in Brazil: A POOLED ANALYSIS AND OVERVIEW OF HETEROGENEITY IN NATIONAL AND INTERNATIONAL STUDIES

PURPOSE

This study aimed to propose reference standards for cardiorespiratory fitness (CRF) for Brazil from a pooled analysis and to compare peak oxygen uptake (V˙ o2peak ) in Brazilian, United States (US), and Norwegian samples, exploring possible national and international differences.

METHODS

Reference values for treadmill V˙ o2peak in three different Brazilian regions were assessed from previous publications. We analyzed available samples to assess possible differences, generate weighted average data for Brazil, and compared them with US and Norwegian data.

RESULTS

Brazilian reference values had a lower V˙ o2peak value for the Northeast region and a higher V˙ o2peak value for the Southeast region for all sex and age groups. International comparisons with the Brazilian pooled data (n = 26661) revealed higher values for the Norwegian sample (n = 3810) and lower values for the US sample (n = 16278). The observed heterogeneity in CRF is possibly related to differences in anthropometric (weight, height) and socioeconomic factors, which differed among the samples. Also, Brazilian data showed a curvilinear V˙ o2peak age reduction trend rather than the linear characteristic commonly utilized, and the regression curves were different from those for US and Norwegian data.

CONCLUSION

This study provides new CRF reference standards for Brazil. After pooling data from three Brazilian regions, a comparison revealed notable differences between regions, evidencing a negative gradient from Southern to Northern regions. Similarly, the international comparisons between Brazil, US, and Norway data revealed CRF heterogeneity, with differences in the V˙ o2peak values and in the age relationship patterns. These findings reinforce the importance of using national- or regional-specific V˙ o2peak reference values, ensuring proper CRF evaluation.

Normal References of Peak Oxygen Uptake for Cardiorespiratory Fitness Measured with Cardiopulmonary Exercise Testing in Chinese Adults

INTRODUCTION

This study aims to establish normal reference values of peak oxygen uptake (VO_2peak) for cardiorespiratory fitness (CRF) in Chinese adults using cardiorespiratory exercise testing (CPET).

METHODS

A cross-sectional study was done in four communities, two in the North (Beijing) and two in the South (Hezhou, Guangxi) of China from 1 January 2017 to 31 December 2018, with one urban and one rural in each region. Out of 1642 participants screened, 1114 were eligible and completed CPET using a cycle ergometer (Ergosana320F) without abnormal ECG and were included in the analysis. The 2nd and 98th percentiles of V·O_2peak were used as the lower and upper limits of the normal reference values.

RESULTS

Significant difference in mean V·O_2peak was shown between men (27.0 mL·min^-1·kg^-1) and women (23.7 mL·min^-1·kg^-1). The mean V·O_2peak decreased with age in both sexes, from 35.8 mL·min^-1·kg^-1 in age 20-29 years to 20.5 mL·min^-1·kg^-1 in 70-79 years in men and from 29.2 mL·min^-1·kg^-1 to 17.0 mL·min^-1·kg^-1 in women. Thus, the age- and sex-specific normal reference values of V·O_2peak were presented for each 10-year age group by men and women separately.

CONCLUSIONS

This first community-based study in China provides age- and sex-specific normal references of V·O_2peak as a measure of CRF in Chinese adults, which differed significantly from those established in Western populations. Future studies with national representative samples should be warranted.

Prenatal exposure to ambient air pollution and adverse birth outcomes: An umbrella review of 36 systematic reviews and meta-analyses

Multiple systematic reviews and meta-analyses linked prenatal exposure to ambient air pollutants to adverse birth outcomes with mixed findings, including results indicating positive, negative, and null associations across the pregnancy periods. The objective of this study was to systematically summarise systematic reviews and meta-analyses on air pollutants and birth outcomes to assess the overall epidemiological evidence. Systematic reviews with/without meta-analyses on the association between air pollutants (NO₂, CO, O₃, SO₂, PM_2.5, and PM₁₀) and birth outcomes (preterm birth; stillbirth; spontaneous abortion; birth weight; low birth weight, LBW; small-for-gestational-age) up to March 30, 2022 were included. We searched PubMed, CINAHL, Scopus, Medline, Embase, and the Web of Science Core Collection, systematic reviews repositories, grey literature databases, internet search engines, and references of included studies. The consistency in the directions of the effect estimates was classified as more consistent positive or negative, less consistent positive or negative, unclear, and consistently null. Next, the confidence in the direction was rated as either convincing, probable, limited-suggestive, or limited non-conclusive evidence. Final synthesis included 36 systematic reviews (21 with and 15 without meta-analyses) that contained 295 distinct primary studies. PM_2.5 showed more consistent positive associations than other pollutants. The positive exposure-outcome associations based on the entire pregnancy period were more consistent than trimester-specific exposure averages. For whole pregnancy exposure, a more consistent positive association was found for PM_2.5 and birth weight reductions, particulate matter and spontaneous abortion, and SO₂ and LBW. Other exposure-outcome associations mostly showed less consistent positive associations and few unclear directions of associations. Almost all associations showed probable evidence. The available evidence indicates plausible causal effects of criteria air pollutants on birth outcomes. To strengthen the evidence, more high-quality studies are required, particularly from understudied settings, such as low-and-middle-income countries. However, the current evidence may warrant the adoption of the precautionary principle.

High Cardiorespiratory Fitness Protects against Molecular Impairments of Metabolism, Heart, and Brain with Higher Efficacy in Obesity-Induced Premature Aging

BACKGRUOUND

High cardiorespiratory fitness (CRF) protects against age-related diseases. However, the mechanisms mediating the protective effect of high intrinsic CRF against metabolic, cardiac, and brain impairments in non-obese versus obese conditions remain incompletely understood. We aimed to identify the mechanisms through which high intrinsic CRF protects against metabolic, cardiac, and brain impairments in non-obese versus obese untrained rats.

METHODS

Seven-week-old male Wistar rats were divided into two groups (n=8 per group) to receive either a normal diet or a highfat diet (HFD). At weeks 12 and 28, CRF, carbohydrate and fatty acid oxidation, cardiac function, and metabolic parameters were evaluated. At week 28, behavior tests were performed. At the end of week 28, rats were euthanized to collect heart and brain samples for molecular studies.

RESULTS

The obese rats exhibited higher values for aging-related parameters than the non-obese rats, indicating that they experienced obesity-induced premature aging. High baseline CRF levels were positively correlated with several favorable metabolic, cardiac, and brain parameters at follow-up. Specifically, the protective effects of high CRF against metabolic, cardiac, and brain impairments were mediated by the modulation of body weight and composition, the lipid profile, substrate oxidation, mitochondrial function, insulin signaling, autophagy, apoptosis, inflammation, oxidative stress, cardiac function, neurogenesis, blood-brain barrier, synaptic function, accumulation of Alzheimer's disease-related proteins, and cognition. Interestingly, this effect was more obvious in HFD-fed rats.

CONCLUSION

The protective effect of high CRF is mediated by the modulation of several mechanisms. These effects exhibit greater efficacy under conditions of obesity-induced premature aging.

Exploring Moderators of the Effect of High vs. Low-to-Moderate Intensity Exercise on Cardiorespiratory Fitness During Breast Cancer Treatment – Analyses of a Subsample From the Phys-Can RCT

Introduction

The results from the physical training and cancer randomized controlled trial (Phys-Can RCT) indicate that high intensity (HI) strength and endurance training during (neo-)adjuvant cancer treatment is more beneficial for cardiorespiratory fitness (CRF, measured as peak oxygen uptake [VO2peak]) than low-to-moderate intensity (LMI) exercise. Adherence to the exercise intervention and demographic or clinical characteristics of patients with breast cancer undergoing adjuvant treatment may moderate the exercise intervention effect on VO2peak. In this study, the objective was to investigate whether baseline values of VO2peak, body mass index (BMI), time spent in moderate- to vigorous-intensity physical activity (MVPA), physical fatigue, age, chemotherapy treatment, and the adherence to the endurance training moderated the effect of HI vs. LMI exercise on VO2peak.

Materials and Methods

We used data collected from a subsample from the Phys-Can RCT; women who were diagnosed with breast cancer and had a valid baseline and post-intervention VO2peak test were included (n = 255). The exercise interventions from the RCT included strength and endurance training at either LMI, which was continuous endurance training at 40–50% of heart rate reserve (HRR), or at HI, which was interval training at 80–90% of HRR, with similar exercise volume in the two groups. Linear regression analyses were used to investigate moderating effects using a significance level of p &lt; 0.10. Statistically significant interactions were examined further using the Johnson–Neyman (J-N) technique and regions of significance (for continuous variables) or box plots with adjusted means of post-intervention VO2peak (for binary variables).

Results

Age, as a continuous variable, and adherence, dichotomized into &lt; or &gt; 58% based on median, moderated the effect of HI vs. LMI on CRF (B = −0.08, 95% CI [−0.16, 0.01], pinteraction = 0.06, and B = 1.63, 95% CI [−0.12, 3.38], pinteraction = 0.07, respectively). The J-N technique and regions of significance indicated that the intervention effect (HI vs. LMI) was positive and statistically significant in participants aged 61 years or older. Baseline measurement of CRF, MVPA, BMI, physical fatigue, and chemotherapy treatment did not significantly moderate the intervention effect on CRF.

Conclusion

Women with breast cancer who are older and who have higher adherence to the exercise regimen may have larger effects of HI exercise during (neo-)adjuvant cancer treatment on CRF.

Estimating Cardiorespiratory Fitness Without Exercise Testing or Physical Activity Status in Healthy Adults: Regression Model Development and Validation

Background

Low cardiorespiratory fitness (CRF) is an independent predictor of morbidity and mortality. Most health care settings use some type of electronic health record (EHR) system. However, many EHRs do not have CRF or physical activity data collected, thereby limiting the types of investigations and analyses that can be done.

Objective

This study aims to develop a nonexercise equation to estimate and classify CRF (in metabolic equivalent tasks) using variables commonly available in EHRs.

Methods

Participants were 42,676 healthy adults (female participants: n=9146, 21.4%) from the Aerobics Center Longitudinal Study examined from 1974 to 2005. The nonexercise estimated CRF was based on sex, age, measured BMI, measured resting heart rate, measured resting blood pressure, and smoking status. A maximal treadmill test measured CRF.

Results

After conducting nonlinear feature augmentation, separate linear regression models were used for male and female participants to calculate correlation and regression coefficients. Cross-classification of actual and estimated CRF was performed using low CRF categories (lowest quintile, lowest quartile, and lowest tertile). The multiple correlation coefficient (R) was 0.70 (mean deviation 1.33) for male participants and 0.65 (mean deviation 1.23) for female participants. The models explained 48.4% (SE estimate 1.70) and 41.9% (SE estimate 1.56) of the variance in CRF for male and female participants, respectively. Correct category classification for low CRF (lowest tertile) was found in 77.2% (n=25,885) of male participants and 74.9% (n=6,850) of female participants.

Conclusions

The regression models developed in this study provided useful estimation and classification of CRF in a large population of male and female participants. The models may provide a practical method for estimating CRF derived from EHRs for population health research.

Cross sectional determinants of VO2 max in free living Iranians: Potential role of metabolic syndrome components and vitamin D status

BACKGROUND AND AIMS

The purpose of the study was to evaluate the determinants of cardiorespiratory fitness (CRF) in Iranian adults and the potential contribution of vitamin D status.

METHODS

In this cross-sectional study 264 cases (116 men and 147 women aged 18-70 years old were participated. Maximal oxygen consumption (VO_{2 max}) was measured by the Bruce protocol utilizing treadmill exercise testing. Anthropometric data, body composition and fasting blood glucose and lipid concentrations were measured. Serum levels of 25-hydroxyvitamin D (25(OH)D) and 1,25-dihydroxyvitamin D (1,25(OH)₂D) were assessed using enzyme-linked immunosorbent assay. Stepwise linear regression analysis was applied to determine significant predictors of VO2 peak. We tested non-linear (quadratic and cubic terms) versus linear association of adjusted (for determinants) VO2 max and vitamin D levels.

RESULTS

Multiple regression results showed that fat free mass, HDL-C and physical activity, waist circumference, age and sex were determinants of VO_{2 peak}. All of these explained the 65.3% of VO2 peak. There was a non-linear cubic association (R² = 0.03, p = 0.046) between serum 25(OH)D and adjusted VO2 peak in which 25(OH)D in people with a high 25(OH)D levels (>60 nmol/L), had better fitness and those with serum 25(OH) less than 20 nmol/L. We found no linear and non-linear associations between serum 1,25(OH)₂ D and adjusted VO_{2 max}.

CONCLUSIONS

Our results showed that waist circumference and HDL-C, as components of metabolic syndrome, contribute ∼2% to the variance in VO_{2 max}. Moreover, high concentrations of 25(OH)D but not 1,25(OH)₂ D may make additional contributions to CRF.

Add-on exercise interventions for smoking cessation in people with mental illness: a systematic review and meta-analysis

BACKGROUND

Smoking is the most common substance use disorder among people with mental illness. In contrast to people without mental illness, among whom the proportion of smokers has declined in recent decades, the proportion of smokers among people with mental illness remains high. There is a growing body of literature suggesting the use of exercise interventions in combination with smoking cessation in people without mental illness, but to our knowledge the available studies on this treatment option in people with mental illness have not been systematically reviewed. Therefore, this systematic review and meta-analysis aims to assess the effectiveness of exercise interventions as an adjunctive treatment for smoking cessation in people with mental illness.

METHODS

Electronic databases (PubMed, Web of Science, PsycInfo, Sport Discus and Base) were searched for randomised controlled trials and prospective single-group studies that investigated exercise interventions in combination with smoking cessation programmes alone or in comparison with a control group in people with mental illness. A meta-analysis using the Mantel-Haenszel fixed-effect model was conducted to estimate the overall effect of treatment on smoking cessation (abstinence rate at the end of the intervention and at 6-month follow-up).

RESULTS

Six studies, five randomised controlled trials and one study with a prospective single-group design, were included in the systematic review and four randomised controlled trials were included in the meta-analysis. The meta-analysis found a significantly higher abstinence rate after additional exercise at the end of the intervention [risk ratio (RR) 1.48, 95% confidence interval (CI) 1.13-1.94], but not at the 6-month follow-up (RR 1.34, 95% CI 0.89-2.04).

CONCLUSIONS

Exercise appears to be an effective adjunctive therapy to temporarily increase abstinence rates in individuals with mental illness at the end of the intervention. However, due to the small number of included studies and some risk of bias in the included studies, the results should be treated with caution. Therefore, future studies with larger samples are needed to provide a more accurate estimate of the effect in people with mental illness. Registration The systematic review and meta-analysis were registered in the International Prospective Register of Systematic Reviews (PROSPERO) (registration number: CRD42020178630).

Electrocortical correlates of the association between cardiorespiratory fitness and sustained attention in young adults

Cardiorespiratory fitness is thought to be positively related to sustained attention. However, the underlying mechanisms of this relationship have yet to be fully elucidated. The objective of this study was to i) explore the relationship between cardiorespiratory fitness and sustained attention in 72 young adults (18-37 years old) and ii) provide insight on the electrocortical dynamics supporting sustained attention performance in individuals differing in cardiorespiratory fitness by means of EEG topographic analyses and source localization. Behaviorally, cardiorespiratory fitness was related to faster response times and higher accuracy in the psychomotor vigilance task even when adjusting the model with confounding variables such as age, body mass index and chronic physical activity. However, there was no relationship between cardiorespiratory fitness and the classic vigilance decrement observed in the sustained attention task. At the electrocortical level, higher cardiorespiratory fitness was related to increased global field power (310-333 ms poststimulus) localized in the posterior cingulate cortex (BA 30) followed by changes in scalp topographies around the P3b ERP component (413-501 ms poststimulus), which corresponded to earlier activation of the supplementary motor areas (BA 6). This is the first study using high-density EEG, which harnesses the whole spatiotemporal dynamics of the relationship between cardiorespiratory fitness and sustained attention in young adults.

Lifestyle Matters: Effects of Habitual Physical Activity on Driving Skills in Older Age

Research on multitasking driving has suggested age-related deterioration in driving performance. It has been shown that physical and cognitive functioning, which are related to driving performance and decline with aging, are positively associated with physical activity behavior. This study aimed to explore whether driving performance decline becomes severe with advancing age and whether physical activity behavior modifies age-related deterioration in driving performance. A total of one hundred forty-one healthy adults were categorized into three groups based on their age; old-old (74.21 ± 2.33 years), young-old (66.53 ± 1.50 years), and young adults (23.25 ± 2.82 years). Participants completed a realistic multitasking driving task. Physical activity and cardiorespiratory fitness levels were evaluated. Older groups drove more slowly and laterally than young adults, and old-old adults drove slower than young-old ones across the whole driving course. Physical activity level did not interact with the aging effect on driving performance, whereas cardiovascular fitness interacted. Higher-fitness young-old and young adults drove faster than higher-fitness old-old adults. Higher-fitness old adults drove more laterally than higher-fitness young adults. The present study demonstrated a gradual decline in driving performance in old adults, and cardiorespiratory fitness interacted with the aging effect on driving performance. Future research on the interaction of aging and physical activity behavior on driving performance in different age groups is of great value and may help deepen our knowledge.

A Systematic Review and Meta-Analysis of Tai Chi Training in Cardiorespiratory Fitness of Elderly People

Objectives

The purpose of this study was to investigate the influence of Tai Chi on cardiorespiratory fitness (CRF) in elderly people using meta-analysis.

Methods

This study used seven electronic databases and data retrieved from randomized controlled trials (RCTs) investigating the role of Tai Chi on CRF in the elderly. All these 24 RCTs were screened and selected from 7 literature databases. The Stata 11.2 software (StataCorp, USA) was used for the meta-analysis, subgroup analysis, and bias test, while the Cochrane Collaboration's tool was used for the assessment of the risk of bias (RoB). 4 researchers independently participated in sample selection, data extraction, and RoB assessment.

Results

Following the inclusion criteria, 24 eligible studies were included in our analysis. The meta-analysis indicated that Tai Chi practice significantly increased the maximum rate of oxygen consumption (VO_{2 max}) (weighted mean difference (WMD)  = 3.76, 95% CI: 1.25 to 6.26, P < 0.1), leading to an overall reduction in the heart rate (HR) (WMD  = −1.84, 95% CI: −2.04 to −1.63, P  ≤ 0.001) and an increase in the O_{2 pulse} (WMD = 0.94, 95% CI: 0.60 to 1.28, P ≤ 0.001) in individuals who practiced Tai Chi regularly compared with those who did not. The subgroup analysis suggested that overall in those who practiced Tai Chi, males (WMD = 1.48, 95% CI: 0.85 to 2.12, P ≤ 0.001) had higher O_{2 pulse} than females (WMD = 0.73, 95% CI: 0.33 to 1.12, P ≤ 0.001). The subgroup analysis also showed an increase in the vital capacity (VC) (WMD = 316.05, 95% CI: 239.74 to 392.35, P ≤ 0.001) in individuals practicing Tai Chi. When the samples were further stratified by Tai Chi practicing time, the subgroup analysis suggested that individuals practicing Tai Chi over a period of 24 weeks showed no significant difference in VC (WMD = 82.95, 95% CI: -98.34 to 264.23, P=0.370), while those practicing Tai Chi over a period of 48 weeks showed a significant increase (WMD = 416.62, 95% CI: 280.68 to 552.56, P ≤ 0.001). Furthermore, the subgroup analysis demonstrated that the increase in VC is significantly correlated with the Tai Chi practicing time (WMD = 344.97, 95% CI: 227.88 to 442.06, P ≤ 0.001).

Conclusion

Regular Tai Chi practice could improve the CRF in the elderly, as indicated by significant improvement in indicators including VO_2max, O_2pulse, VC, and HR. However, gender and practice time might influence the overall beneficial outcomes.

Estimation of maximal oxygen uptake using the heart rate ratio method in male recreational football players

Maximal oxygen uptake (VO_2max) is associated with cardiovascular and metabolic health in the general population. The heart rate (HR) ratio method (HR_ratio) is a valid, easy and accessible method for estimating VO_2max in well-trained subjects. This study examined the validity of using the HR_ratio to estimate VO_2max in recreational football players in the untrained and trained states. Sixty-six participants (age 39.3 ± 5.8 years) were tested pre-training and 28 after 12 weeks, for VO_2max assessment, running on a treadmill alternating speed (1 km h⁻¹) and inclination (1%) increments every 30 s until exhaustion. Maximal HR (HR_max) was assessed directly with a multiple approach and estimated with selected equations. Resting HR (HR_rest) was measured in supine position, after 15 min of rest. The HR_ratio method considers the product of HR_max/HR_rest ratio by a theoretical proportionality factor (15 ml kg⁻¹ min⁻¹, TPF) to estimate VO_2max. This population-specific proportionality factor (SPF) was 14.6 ± 2.6 ml kg⁻¹ min⁻¹. In the untrained state (n = 66), participants’ actual VO_2max (41.3 ± 6.2 ml kg⁻¹ min⁻¹) was moderately lower (~ 2 ml kg⁻¹ min⁻¹) than the estimated VO_2max using the TPF. A nonsignificant difference (0.7 ml kg⁻¹ min⁻¹) was found when the VO_2max was estimated using the SPF. When using HR_max equations and the TPF, a small nonsignificant difference (~ 1.5 ml kg⁻¹ min⁻¹) was reported between actual and estimated VO_2max. In the trained state (n = 28), the estimated VO_2max values were not significantly different from the actual VO_2max (44.2 ± 5.2 ml kg⁻¹ min⁻¹), with large effect sizes when considering TPF and estimated HR_max. The results of this study provide evidence of the applicability of HR_ratio in estimating VO_2max in male adult/middle-aged recreational football players.