Manuel J. Castillo

Physical fitness in childhood and adolescence: a powerful marker of health

This review aims to summarize the latest developments with regard to physical fitness and several health outcomes in young people. The literature reviewed suggests that (1) cardiorespiratory fitness levels are associated with total and abdominal adiposity; (2) both cardiorespiratory and muscular fitness are shown to be associated with established and emerging cardiovascular disease risk factors; (3) improvements in muscular fitness and speed/agility, rather than cardiorespiratory fitness, seem to have a positive effect on skeletal health; (4) both cardiorespiratory and muscular fitness enhancements are recommended in pediatric cancer patients/survivors in order to attenuate fatigue and improve their quality of life; and (5) improvements in cardiorespiratory fitness have positive effects on depression, anxiety, mood status and self-esteem, and seem also to be associated with a higher academic performance. In conclusion, health promotion policies and physical activity programs should be designed to improve cardiorespiratory fitness, but also two other physical fitness components such us muscular fitness and speed/agility. Schools may play an important role by identifying children with low physical fitness and by promoting positive health behaviors such as encouraging children to be active, with special emphasis on the intensity of the activity.

Predictive Validity of Health-Related Fitness in Youth: A Systematic Review

The objective of the present systematic review was to investigate whether physical fitness in childhood and adolescence is a predictor of cardiovascular disease (CVD) risk factors, events and syndromes, quality of life and low back pain later in life. Physical fitness-related components were: cardiorespiratory fitness, musculoskeletal fitness, motor fitness and body composition. Adiposity was considered as both exposure and outcome. The results of 42 studies reporting the predictive validity of health-related physical fitness for CVD risk factors, events and syndromes as well as the results of five studies reporting the predictive validity of physical fitness for low back pain in children and adolescents were summarised. Strong evidence was found indicating that higher levels of cardiorespiratory fitness in childhood and adolescence are associated with a healthier cardiovascular profile later in life. Muscular strength improvements from childhood to adolescence are negatively associated with changes in overall adiposity. A healthier body composition in childhood and adolescence is associated with a healthier cardiovascular profile later in life and with a lower risk of death. The evidence was moderate for the association between changes in cardiorespiratory fitness and CVD risk factors, and between cardiorespiratory fitness and the risk of developing the metabolic syndrome and arterial stiffness. Moderate evidence on the lack of a relationship between body composition and low back pain was found. Due to a limited number of studies, inconclusive evidence emerged for a relationship between muscular strength or motor fitness and CVD risk factors, and between flexibility and low back pain.

Field-based fitness assessment in young people: the ALPHA health-related fitness test battery for children and adolescents

The present study summarises the work developed by the ALPHA (Assessing Levels of Physical Activity) study and describes the procedures followed to select the tests included in the ALPHA health-related fitness test battery for children and adolescents. The authors reviewed physical fitness and health in youth findings from cross-sectional studies. The authors also performed three systematic reviews dealing with (1) the predictive validity of health-related fitness, (2) the criterion validity of field-based fitness tests and (3) the reliability of field-based fitness tests in youth. The authors also carried out 11-methodological studies to determine the criterion validity and the reliability of several field-based fitness tests for youth. Finally, the authors performed a study in the school setting to examine the reliability, feasibility and safety of the selected tests. The selected fitness tests were (1) the 20 m shuttle run test to assess cardiorespiratory fitness; (2) the handgrip strength and (3) standing broad jump to assess musculoskeletal fitness, and (4) body mass index, (5) skinfold thickness and (5) waist circumference to assess body composition. When there are time limits, the authors propose the high-priority ALPHA health-related fitness test battery, which comprises all the evidence-based fitness tests except the measurement of the skinfold thickness. The time required to administer this battery to a group of 20 youth by one physical education teacher is less than 2 h. In conclusion, the ALPHA fitness tests battery is valid, reliable, feasible and safe for the assessment of health-related physical fitness in children and adolescents to be used for health monitoring purposes at population level.

Low Level of Physical Fitness in Spanish Adolescents. Relevance for Future Cardiovascular Health (AVENA Study)

INTRODUCTION AND OBJECTIVES Several studies have demonstrated that physical fitness in childhood and adolescence is related to cardiovascular risk in adulthood. Current data on the physical fitness of Spanish adolescents are not available. Therefore, the aims of this study were: a) to assess the physical fitness of Spanish adolescents and establish reference values for use in health and educational settings as indicators of cardiovascular health, and b) to determine the percentage of Spanish adolescents below the minimum level of aerobic fitness needed to guarantee future cardiovascular health. SUBJECTS AND METHOD The modified EUROFIT battery of tests was used to assess physical fitness in a representative sample of Spanish adolescents (n=2859; 1357 boys and 1502 girls) taking part in the AVENA (Alimentación y Valoración del Estado Nutricional de los Adolescentes) study. RESULTS Standard parameters for the physical condition of Spanish adolescents are reported in this study. The 5th percentile for maximum aerobic capacity (Course Navette test) ranged from 2.0-3.3 palier in boys and from 1.4-1.9 palier in girls. The findings indicate that, on the basis of aerobic fitness, approximately 20% of Spanish adolescents have an increased risk of future cardiovascular disease. This subgroup also performed poorly in all other tests of physical fitness used. CONCLUSIONS The results reported in this study enable the level of physical fitness in adolescents to be interpreted as an indicator of future cardiovascular health. They also indicate that the physical fitness of Spanish adolescents must be improved to help protect against cardiovascular disease in adulthood.

Cardiorespiratory Fitness and Sedentary Activities Are Associated with Adiposity in Adolescents

Objective: To determine whether physical activity, sedentary activities, and/or cardiorespiratory fitness are related to waist circumference in adolescents, as previously reported in adults.

Health-related fitness assessment in childhood and adolescence: a European approach based on the AVENA, EYHS and HELENA studies

Results from cross-sectional and longitudinal studies such as Alimentación y Valoración del Estado Nutricional en Adolescentes: Food and Assessment of the Nutritional Status of Spanish Adolescents (AVENA) and the European Youth Heart Study (EYHS) respectively, highlight physical fitness as a key health marker in childhood and adolescence. Moderate and vigourous levels of physical activity stimulate functional adaptation of all tissues and organs in the body (i.e. improve fitness), thereby also making them less vulnerable to lifestyle-related degenerative and chronic diseases. To identify children and adolescents at risk for these major public health diseases and to be able to evaluate the effects of alternative intervention strategies in European countries and internationally, comparable testing methodology across Europe has to be developed, tested, agreed upon and included in the health monitoring systems currently under development by the European Commission (EC): the Directorate General for Health and Consumer Affairs (DG SANCO); the Statistical Office of the European Communities (EUROSTAT), etc. The Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study group plans, among other things, to describe the health-related fitness of adolescents in a number of European countries. Experiences from AVENA and EYHS will be taken advantage of. This review summarises results and experiences from the developmental work so far and suggests a set of health-related fitness tests for possible use in future health information systems.

. A prospective study of muscular strength and all-cause mortality in men with hypertension.

OBJECTIVES This study sought to assess the impact of muscular strength on mortality in men with hypertension. BACKGROUND Muscular strength is inversely associated with mortality in healthy men, but this association has not been examined in men with hypertension. METHODS We followed 1,506 hypertensive men age 40 years and older enrolled in the Aerobics Center Longitudinal Study from 1980 to 2003. Participants received an extensive medical examination at baseline. Muscular strength was quantified by combining 1 repetition maximum (1-RM) measures for leg and bench press and cardiorespiratory fitness assessed by maximum exercise test on a treadmill. RESULTS During an average follow-up of 18.3 years, 183 deaths occurred. Age-adjusted death rates per 10,000 person-years across incremental thirds of muscular strength were 81.8, 65.5, and 52.0 (p < 0.05 for linear trend). Multivariable Cox regression hazard ratios were 1.0 (reference), 0.81 (95% confidence interval [CI]: 0.57 to 1.14), and 0.59 (95% CI: 0.40 to 0.86) across incremental thirds of muscular strength. After further adjustment for cardiorespiratory fitness, those participants in the upper third of muscular strength still had a lower risk of death (hazard ratio [HR]: 0.66; 95% CI: 0.45 to 0.98). In the muscular strength and CRF combined analysis, men simultaneously in the upper third of muscular strength and high fitness group had the lowest mortality risk among all combination groups (HR: 0.49; 95% CI: 0.30 to 0.82), with men in the lower third of muscular strength and low fitness group as reference. CONCLUSIONS High levels of muscular strength appear to protect hypertensive men against all-cause mortality, and this is in addition to the benefit provided by cardiorespiratory fitness.

Television watching, videogames, and excess of body fat in Spanish adolescents: The AVENA study

OBJECTIVE We assessed the individual association of sedentary behaviors with the risk of overweight and excess body fat (overfat) in adolescents. METHODS A representative sample (1960 subjects, 1012 males, age 13-18.5 y) of Spanish adolescents was studied within the framework of the Alimentación y Valoración del Estado Nutricional de los Adolescentes (AVENA) study. Television (TV) watching, videogame and computer usage, doing homework, and the way students got to school, physical activity, and socioeconomic status were analyzed. Anthropometrics were measured to describe overweight (International Obesity Task Force cutoffs for body mass index) and overfat (body fat percentage >85th percentile). RESULTS When all subjects were considered as an entire group, the overweight risk increased by 15.8% (P < 0.05) per increasing hour of TV watching. The overweight risks decreased by 32.5% in females, 22% per increasing year of age, and 12.5% by increasing socioeconomic status by 1 U (all Ps < 0.05). The obesity risks decreased with age by 17.8% per year in males and 27.1% in females (both Ps < 0.05). The overfat risks increased by 26.8% and 9.4% per increasing hour of TV and weekend videogame usage, respectively (both Ps < 0.05). In males, the overfat risk increased by 21.5% per increasing hour in weekend videogame usage (P < 0.05). Each hour of TV use increased the overfat risks by 22% in males and 28.3% in females (both Ps < 0.05). CONCLUSIONS Time spent watching TV increased the risk of overweight and obesity in Spanish adolescents, but the effect was influenced by age, sex, and socioeconomic status. Moreover, an excess of body fat was more directly explained by the time spent watching TV and playing videogames during the weekend.

El perfil lipídico-metabólico en los adolescentes está más influido por la condición física que por la actividad física (estudio AVENA)*

Introduction and objectives. To determine whether the level of physical activity or physical fitness (i.e., aerobic capacity and muscle strength) in Spanish adolescents influences lipid and metabolic profiles. Methods. From a total of 2859 Spanish adolescents (age 13.0-18.5 years) taking part in the Diet and Appraisal of Nutrition State in Adolescents 460 (248 male, 212 female) were randomly selected for blood analysis. Their level of physical activity was determined by questionnaire. Aerobic capacity was assessed using the Course-Navette test. Muscle strength was evaluated using flexed arm. A lipidmetabolic cardiovascular risk index was derived from the levels of triglycerides, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and glucose. Results. No relationship was found between the level of physical activity and lipid‐metabolic index in either sex. In contrast, there was an inverse relationship between the lipid‐metabolic index and aerobic capacity in males (P=.003) after adjustment for physical activity level and muscle strength. In females, a favorable lipid‐metabolic index was associated with greater muscle strength (P=.048) after adjustment for aerobic capacity.

Health-related fitness in adolescents: underweight, and not only overweight, as an influencing factor. The AVENA study

This study investigated differences in health‐related fitness (20‐m shuttle run, handgrip, bent arm hang, standing long jump, shuttle run 4 × 10 m and sit and reach tests) in 2474 Spanish adolescents (1196 boys and 1278 girls; age 13–18.5 years) classed as underweight, normal weight, overweight or obese according to body mass index. Body fat and fat‐free mass were derived from skinfold thickness. The prevalence of underweight was higher than obesity in girls (4.8% vs 3.0%, respectively; P<0.05) and the opposite in boys (3.9% vs 5.8%, respectively; P<0.05). Underweight was associated with a higher performance in the bent arm hang test in girls (P<0.05) and a lower performance in handgrip in both genders (P<0.01) compared with normal weight. Overweight and obese adolescents presented a lower performance in 20‐m shuttle run, bent arm hang, standing long jump and shuttle run 4 × 10 m tests (P<0.001), but a higher performance in handgrip strength (P<0.001) compared with normal weight. In weight‐bearing tests, the association became non‐significant after adjusting for fat mass. In conclusion, not only overweight and obesity but also underweight seem to be determinants of health‐related fitness in adolescents. The associations could be related to differences in body composition.