Time measurement validity and reliability of the 4 × 10-m shuttle run test in adult population: The ADULT-FIT project.

OBJECTIVES: The purpose of this study was to analyze the time measurement validity and reliability (between raters and test-retest) of the 4 × 10-m shuttle run test to assess motor fitness in adults, according to gender, age, and physical activity levels. DESIGN: Cross-sectional. A total of 230 adults (86 women) aged 18-64 years participated in the study. METHODS: The time taken to complete the 4 × 10-m shuttle run test was recorded simultaneously by a trained and an untrained rater (inter-rater reliability) and by photoelectric cells (time measurement validity). 48-72 h later, the test was repeated under the same conditions (test-retest reliability). RESULTS: The systematic error for trained rater vs. photocell was close to zero (0.0125, p < 0.01), with an effect size of 0.006; and for both, untrained rater vs. photocell and trained rater vs. untrained rater was ∼0.2 s (p < 0.001) with an effect size of 0.09. For the test-retest reliability, the systematic error was 0.05 s (p < 0.001), with an effect size of 0.26, the intraclass correlation coefficient was 0.998 and the coefficient of variation reported a variability of 0.73 %. Results were not influenced by gender and age, while these improved for active vs. non-active participants. CONCLUSIONS: Findings indicate that measurements with trained raters are a valid and reliable method for assessing the 4 × 10-m shuttle run test in adults. It is highly recommended that raters be trained to minimize the measurement error.

Criterion-related validity and reliability of the 2-km walk test and the 20-m shuttle run test in adults: The role of sex, age and physical activity level.

OBJECTIVES: To analyze the criterion-related validity and the reliability of fitness field tests for evaluating cardiorespiratory fitness in adults, by sex, age, and physical activity level. DESIGN: Cross-sectional. METHODS: During 3 weeks, sociodemographic, anthropometric measurements, a treadmill maximal test, the 2-km walk test, and the 20-m SRT were performed in 410 adults aged 18-64 years. Measured and estimated VO2max (by Oja's and Leger's equations) were analyzed. RESULTS: Measured VO2max was associated with estimated VO2max by the 2-km walk test and 20-m SRT (r = 0.784 and r = 0.875, respectively; both p < 0.01). Bland-Altman analysis showed a mean difference of -0.30 ml* kg-1 * min-1 (p < 0.001, d = -0.141) in the 2-km walk test, and 0.86 ml* kg-1 * min-1 (p = 0.051) in the 20-m SRT. Significant mean differences between test and retest were found in the time to complete the 2-km walk test (-1.48 ±â€¯0.51 s, p = 0.004, d = -0.014) and in the final stage reached in the 20-m SRT (0.04 ±â€¯0.01, p = 0.002, d = 0.015). Non-significant differences were found between test and retest in the estimated VO2max by Oja's (-0.29 ±â€¯0.20 ml* kg-1 * min-1, p > 0.05) and Leger's eqs. (0.03 ±â€¯0.04 ml* kg-1 * min-1, p > 0.05). Moreover, both test results and estimated VO2max equations showed a high test-retest reliability. CONCLUSIONS: Both tests were valid and reliable for evaluating cardiorespiratory fitness in adults aged 18-64 years, regardless of sex, age, and physical activity level.

Influence of Volume and Bouts of Sedentary Time and Physical Activity on School-Aged Youth's Physical Fitness: The UP & DOWN Longitudinal Study.

BACKGROUND: The aim of this study was to examine associations of total volume and bouts of sedentary time (ST) and moderate to vigorous physical activity (MVPA) with physical fitness (PF) in youth. METHODS: This was a 2-year follow-up study with 1418 children and adolescents (51.7% boys). Accelerometers were used to assess ST and MVPA. Cardiorespiratory and muscular fitness values were objectively measured and combined in a global PF variable. Weight status was objectively obtained. Linear regression analyses were used to examine the cross-sectional (using scores at baseline) and longitudinal associations (using the change in the variables) of total volume and bouts of ST and MVPA with PF. RESULTS: Total ST was negatively associated with global PF (ß = -0.488, P < .001 in cross-sectional analysis; ß = -0.234, P = .003 in longitudinal analysis). However, this association was not independent of MVPA. Total volume of MVPA showed a positive association with global PF independently of ST and weight status (ß = 0.285, P < .001 in cross-sectional analysis; ß = 0.119, P = .001 in longitudinal analysis). Longitudinal associations found between ST and MVPA accumulated in bouts of various lengths and global PF became nonsignificant when their respective total volumes are included in the model. CONCLUSIONS: These results underline the need to accumulate minutes of MVPA, regardless of the bout duration, to increase PF levels in youth.

Fitness, body composition, and metabolic risk scores in children and adolescents: the UP&DOWN study.

We aimed to analyse the longitudinal association between physical fitness (PF) and body composition (BC) with a metabolic risk score (Met4) in children and adolescents and to elucidate whether the association between PF and Met4 differs when using relativized or absolute fitness variables. A total of 188 children (86 females) and 195 adolescents (97 females) were included. Cardiorespiratory fitness (CRF) was determined by the 20-m shuttle run test, and muscular fitness (MF) was determined by hand grip and standing long jump tests. Height and weight were measured, and the body mass index (Kg/m2) was calculated. Triceps and subscapular skinfolds were assessed to compute body fat percentage. Met4 was computed from systolic blood pressure, triglycerides, high-density lipoprotein cholesterol, and glucose levels. Relative CRF was longitudinally and negatively associated with Met4 in female children (ß = -0.031, p = 0.025), while absolute CRF was positively associated with Met4 in male children and adolescents (ß = 0.000, p < 0.05). Relative upper and lower-body MF were longitudinally and negatively associated with Met4 in female adolescents (ß = -1.347, ß = -0.005, p < 0.05), while absolute lower-body MF was positively associated with Met4 in male children (ß = 0.000, p = 0.019). BC was longitudinally and positively associated with Met4 in male children (ß-ranging from 0.011 to 0.055, all p < 0.05) and male adolescents (ß-ranging from 0.011 to 0.046, all p < 0.05).  Conclusion: BC is more strongly associated with Met4 than PF in children and adolescents. An optimal body weight status should be considered the main objective of health-promoting programs at childhood and adolescence. Furthermore, the way of expressing the fitness variables determines the direction of the association with Met4. What is Known: • Physical fitness is an important health indicator in children and adolescents, with great amount of previous evidence supporting the preventive role of maintaining optimal levels of both cardiorespiratory and muscular fitness for future cardiometabolic issues. What is New: • The way of reporting physical fitness variables can affect the associations between physical fitness features and cardiometabolic outcomes. Since body composition variables have a great impact on both physical fitness and cardiometabolic health, relativizing physical fitness performance by body composition could lead to erroneous conclusions.

Criterion-Related Validity of Field-Based Methods and Equations for Body Composition Estimation in Adults: A Systematic Review.

PURPOSE OF REVIEW: Overweight and obesity are associated to health prognosis. Therefore, body composition assessment is an important health outcome, especially in adult population. We analyzed the criterion-related validity of existing field-based methods and equations for body composition estimation in adults aged 19-64 years. RECENT FINDINGS: One hundred studies met inclusion criteria. The field-based methods, waist circumference (WC), body adiposity index (BAI), and body mass index (BMI) are valid to indicate body adiposity. Likewise, several equations, including the classical Durnin/Womersley equation, Jackson/Pollock equation (males), and Jackson, Pollock, and Ward equation (females), are valid to estimate total body fat mass or body fat percentage. Anthropometric field methods can provide a simple, quick, and easy informative indicators of adiposity in adults. Classical equations, such as Durnin/Womersley equation, Jackson/Pollock equation, and Jackson, Pollock, and Ward equation, are still valid to estimate total body fat mass or body fat percentage in adult population. When choosing estimation equations, specific population characteristics, such as age, weight status, or race ethnicity, should be taken into account. (Trial Registration: Registered on PROSPERO (CRD42020194272)).