Health Related Physical Fitness Evaluation In Adolescents Physical Education Essay
Physical fitness is not a single trait but a combination of aerobic capacity, strength, speed, agility, coordination and flexibility, which together determine a person’s ability to perform physical activity, including those activities related to daily living (Hallal et al, 2006). On a practical, everyday level, physical fitness allows a person to work efficiently, reduce the risk of injury, cope with unforeseen circumstances, and enjoy being active whether for sport, exercise or leisure. Physical fitness has also been revealed as an important health and wellbeing marker and recent results from the several studies such as the HELENA study (2008) have clearly demonstrated that this is also the case in European adolescents (Ortega et al, 2007). Evaluating health status with a whole-person perspective that assesses all spectrums of health from pathology to impairments and limitations in activity and participation is important for proper patient management (Hills et al 2007). Evaluations that emphasize impairments such as limitations in range of motion and strength fail to address the larger psychosocial issues that potentially affect the individual and may result in barriers to future athletic participation. To assess the whole person, a broadly defined construct such as health-related quality of life is valuable (Snyder, 2010). There are several tests which have been developed and are used in the assessment of the fitness of school age children and adolescences. These tests have been carefully selected to be appropriate to their level. Some tests been adapted using lower weights, distances and times, and using simple instructions and modified equipment, while there are others are the same test procedures as used for adults (Topend sports, 2010). Some of these tests include:
FitnessGram – designed to assess the fitness levels of children in grades K-12 (Figure 1).
Presidents Challenge – fitness award program for school age children in the United States Connecticut Physical Fitness Test – a fitness assessment given annually to all students in grades 4, 6, 8, and 10 in the US state of Connecticut.
International Physical Fitness Test – a battery of tests developed to test Arab youth aged 9 to 19 years.
National Physical Fitness Awards – a series of tests of physical fitness for the children of Singapore.
Eurofit – a testing program devised by the Council of Europe for children of school age.
Health-related physical fitness includes the characteristics of functional capacity and is affected by the physical activity level and other lifestyle factors. These battery tests include a variety of health-related physical fitness tests that assess aerobic capacity; muscular strength, muscular endurance, and flexibility; and body composition. Testing and evaluation with children and adolescence is becoming increasingly popular as it is widely reported that childhood and adolescence are crucial periods of life, since dramatic physiological and psychological changes take place at these ages (Ortega et al, 2008). This as it is being reported that lifestyle and healthy/unhealthy behaviours are established during these years, which may influence adult behaviour and health status. (Jackson et al, 2007)
Section 2 – Validity and Reliability of Tests
Children (or their families) involved in lifestyle modification-intervention studies have a tendency to over-report their physical activity, with the result that interventions may favour the intervention group; objective measures of physical activity made on the same children have suggested that such differences can be spurious (Reilly et al 2007). Assessment of interventions aimed at physical activity and sedentary behaviour change should use objective methods, both to confirm that apparent changes in physical activity are real and to quantify the magnitude of any change with confidence. The problem of biased self-reporting of amount and intensity of physical activity using subjective methods – such as questionnaires – almost certainly extends to observational studies and surveys of physical activity in children carried out for surveillance purposes. In the United Kingdom, national surveillance of paediatric physical activity in health surveys still involves subjective (parental) reporting of physical activity and is associated with relatively high apparent levels of physical activity( Reilly et al 2007). In the Scottish Health Survey 2003 75% of 6-10 year olds were reported to exceed the public health target of an accumulated 60 min of moderate to vigorous physical activity (MVPA) per day every day, but recent UK studies that have measured MVPA by accelerometry suggest that ,5% of children and adolescents meet this target Reilly et al, 2007) Subjective measures appear to quantify the perception of physical activity, rather than physical activity, and current methods for national surveillance of the amount and intensity of habitual physical activity in the United Kingdom may provide a false sense of reassurance concerning population levels of physical activity (Ruiz et al, 2006).
A major issue in the testing of adolescents with these test or indeed any tests carried out, is determining the reliability and validity of such tests. Reliability can be defined as the consistency of measurements (Ortega et al, 2007) . When the tests are carried out they should follow a set procedure which is carried out by all administers of these tests as the measures can then be comparable. Another related but different concept is validity. Validity is the ability of the measurement tool to measure what it is designed to measure. The validity of a tool is judged by comparison with a ‘gold standard’ method. Realistically, some amount of error is always present when collecting data. The main components of measurement error are systematic bias (for example, general learning on the tests) and random error due to biological or mechanical variation(Ortega et al, 2006). When testing mass groups of adolescents it is not practical to carry out the gold standard method of testing due to factors such as both financial and time constraints. When researching the methods behind the evaluation of physical fitness testing in adolescents, ensuring the tests were practical was a very common theme across the globe. Several of the fitness battery tests were designed to be carried out within 50 minutes using very simple equipment.
Section 3 – Common Fitness Battery testing tests – (Table 1 & 2)
3.1 – Back-saver sit and reach test (flexibility assessment): A standard box with a small bar, which has to be pushed by the participant, is used to perform the test. The adolescent bends his/her trunk and reaches forward as far as possible from a seated position, with one leg straight and the other bent at the knee. The test is performed once again with the opposite leg. The farthest position of the bar reached by each leg was scored in centimetres and the average of the distances reached by both legs is used in the analysis of the results (Fitnessgram, 2010).
3.2 – Handgrip test (maximum handgrip strength assessment): The handgrip strength test is a simple and economical test that gives practical information on muscle, nerve, bone or joint disorders. A hand dynamometer with adjustable grip is used. The participant squeezes gradually and continuously for at least 2 seconds, performing the test with the right and left hands in turn, using the optimal grip span.11. The average of the scores achieved in both handgrip tests was used in the analysis of the results (Fitnessgram, 2010).
3.3 – Standing broad jump test (lower limb explosive strength assessment): The standing broad jump assesses lower-limb explosive strength. Explosive strength is the ability to carry out a maximal, dynamic contraction of a muscle or muscle group. From a starting position immediately behind a line, standing with feet approximately shoulder’s width apart, the adolescent jumps as far as possible with feet together. The result is recorded in centimetres. A non-slip hard surface, chalk and a tape measure is used to perform the test (Fitnessgram, 2010).
3.4 – The Bosco protocol is composed of three different jumps: (4.1) The Bosco jump protocol includes, among other things, the following type of jumps: squat jump, countermovement jump and Abalakov jump. Performance in squat jump indicates explosive strength of the lower limbs; the countermovement jump assesses explosive strength plus the use of elastic energy; the Abalakov jump assesses explosive strength, plus the use of elastic energy, plus the coordinative capacity using trunk and upper limbs
Squat jump (lower limb explosive strength assessment): the adolescent performs a vertical jump without rebound movements starting from a half-squat position, keeping both knees bent at 90°, the trunk straight and both hands on hips. Previous counter movements are not allowed. (4.2)
Counter movement jump (lower limb explosive strength and elastic component assessment): in a standing position, with legs straight and both hands on hips, the adolescent performs a vertical jump with an earlier fast counter movement. (4.3)
Abalakov jump (lower limb explosive strength, elastic component and intermuscular coordination capacity assessment): the Abalakov jump is similar to the counter movement jump, but now the adolescent is allowed to freely coordinate the arms and trunk movements to reach the maximum height. The jump height is recorded in centimetres.
3.5 – Bent arm hang test (upper limb endurance strength assessment): The bent-arm hang test (also called flexed arm hang) is one of the recommended tests for upper-limb endurance strength. The adolescent hangs from a bar for as long as possible, with the arms bent at 90 degrees. The palms face forward and the chin must be over the bar’s plane. The time spent in this position, to the nearest tenth of a second, is recorded. A cylindrical horizontal bar and a stopwatch are used to perform the test (Eurofit, 2010).
3.6 – 4_10m shuttle run test (speed of movement, agility and coordination assessment): two parallel lines are drawn on the floor 10m apart. The adolescent runs as fast as possible from the starting line to the other line and returns to the starting line, crossing each line with both feet every time. This is performed twice, covering a distance of 40m (4_10 m). Every time the adolescent crosses any of the lines, he/she should pick up (the first time) or exchange (second and third time) a sponge that has earlier been placed behind the lines. The stopwatch is stopped when the adolescent crosses the end line with one foot. The time taken to complete the test is recorded to the nearest tenth of a second. A slip-proof floor, four cones, a stopwatch and three sponges are used to perform the test (Eurofit, 2010).
3.7 – 20-m shuttle run test (cardiorespiratory fitness assessment): Participants are required to run between two lines 20m apart, while keeping pace with audio signals emitted from a pre-recorded CD. The initial speed is 8.5kmh_1, which is increased by 0.5kmh_1 min_1 (1 min equals one stage). Participants are instructed to run in a straight line, to pivot on completing a shuttle, and to pace themselves in accordance with the audio signals. The test is finished when the participant fails to reach the end lines concurrent with the audio signals on two consecutive occasions. Otherwise, the test ends when the participant stops because of fatigue. All measurements are commonly carried out under standardized conditions on an indoor rubber floored gymnasium. The participants are encouraged to keep running as long as possible throughout the course of the test. The last completed stage or half-stage at which the participant drops out is scored. A gymnasium or space large enough to mark out a 20m track, a 20m tape measure, a CD player and a CD with the audio signals recorded are used to perform the test (Eurofit, 2010).
Section 4 – Specific Components of Tests
4.1 – Cardio vascular Fitness:
Cardiovascular fitness is a special form of muscular endurance. It is the efficiency of the heart lungs and vascular system in delivering O2 to the working muscle tissue so physical work can be maintained. Strong and consistent evidence from observational studies found that physical inactivity and poor cardiovascular fitness are associated with higher morbidity and mortality from all causes including cardiovascular diseases and cancer (Mercedes, R. et al 2005). Cardiovascular fitness in childhood and adolescents is a strong indicator for present and future CV, metabolic, skeletal and mental health problems. The metabolic syndrome which is considered a group of risk factors that collectively promote the development of cardiovascular disease and increases the risk of diabetes can be a result of cardiovascular fitness (Gutin et al, 2007). These risk factors include:
High fasting glucose,
High waist circumference,
Low high density lipoprotein cholesterol
High blood pressure.
Aerobic capacity (VO2max) indicates the maximum rate that the respiratory, cardiovascular, and muscular systems can take in, transport, and use oxygen during exercise. This reflects the body’s ability to provide energy in the muscles using oxygen. It is generally expressed relative to body weight (mL.kg.min-1) to account for differences in body size among individuals and to reflect each individual’s ability to carry out weight-bearing tasks(Mercedes, R. et al 2005). Good aerobic capacity (cardio-respiratory fitness) has been shown to reduce the risk of high blood pressure, coronary heart disease, obesity, diabetes, the metabolic syndrome, and some forms of cancer (Gutin et al, 2001). Obesity and heart disease risk factors are known to track through the life span.
Helena study (2002-2006) – 1000 participants were analysed for; dietary intake, Body comp, Physical activity and fitness and plasma lipid and metabolic profile. Risk factors for cardiovascular disease were found to be more favourable in those with higher cardiovascular fitness. Similar study ANEVA in Spain indicates that high levels of cardiovascular fitness are associated with a positive metabolic profile in both overweight and non overweight Spanish adolescents (Table 2) (Gonzalez et al, 2003).
4.2 – Flexibility:
Flexibility which is the range of motion available to a joint or group of joints and stretching are promoted as possible means to offset age related stiffness, reduce the risk of injury to the lower back, improve body posture and symmetry, enhance relaxation, relieve pain, augment physical fitness and optimise functional movement in daily life (Atler 2004). Also in a 25 year longitudinal study, Mikkelsson et al (2006) found that high adolescent flexibility predicted low occurrence of tension neck in men. Due to an increasing number of studies reporting the benefits from increased flexibility both long term and short term flexibility tests such as the sit and reach test (explained above). The sit and reach test as previously mentioned analyses the flexibility of the hamstrings which has been identified by several studies as a potential source of injury. In Feldman (2000) it was found firstly that decreased muscle flexibility and trunk strength have been postulated as risk factors for low back pain but more importantly that poor hamstring flexibility can be associated with low back pain in both adolescents and adults.
4.3 – Body Composition:
Anthropometry is one of the most basic tools for assessing nutritional status, whether over-nutrition or under-nutrition. A variety of methods are available to measure body fatness and body thinness (WHO, 1995). Commonly used techniques for the accurate estimation of body fatness include underwater weighing, dual-energy X-ray absorptiometry (DXA), total body water, total body electrical conductivity, total body potassium, and computed tomography. However, the use of most of these methods is limited to research settings because of their complexity and cost (Mei et al, 2002). The most frequently used tools in fitness battery tests used on children and adolescents are anthropometric-based measurements such as skinfold-thickness or circumference measurements or various height- and weight-based indexes such as weight-for-height, body mass index [BMI; wt (kg)/ht2 (m)] (Mei et al, 2002). Body mass index does not indicate the composition of the body weight. It is an index that provides an estimate of the appropriateness of the weight for the height. Boot et al (1997) compared the validity of a DXA scan to the practical measurements BMI and bioelectrical impedence analysis (BIA). The study found firstly that BMI correlated significantly with % body fat, fat mass, lean tissue mass and bone mineral content measured by DXA. The correlation between BMI and fat mass was stronger in girls than in boys (r = 0.93 in girls and r = 0.85 in boys). The study also found a very strong relationship between lean tissue mass measured by DXA and lean body mass measured by BIA (r = 0.99) (Graph 1). From this study the practical body composition tests commonly carried out in fitness battery tests for adolescents can be considered both valid and reliable.
Body composition tests such as those just discussed may provide a useful indicator for future health risks as high levels of body fatness are associated with increased risk of coronary heart disease, stroke, diabetes, high blood pressure, high cholesterol, some cancers, and joint problems. Obesity and heart disease risk factors are known to track through the life span (Ruiz, 2006).
4.4 – Muscular endurance & Strength.
Balanced, healthy functioning of the musculoskeletal system requires that a specific muscle or muscle group be able to generate force or torque (measured as strength), resist repeated contractions over time or maintain a maximal voluntary contraction for a prolonged period of time (measured as muscular endurance) and to carry out a maximal, dynamic contraction of a muscle or muscle group (measured as explosive strength) (Ruiz, 2006). Common tests which evaluate an adolescents strength and muscular endurance include the standing broad jump, hand grip test and bent arm hang (explained above). Several studies report the future health benefits of increased strength and muscular endurance in adolescents. Barnekow-Bergkvist (2006) reported in a 16 year follow up that high performance in bench press at the age of 16 was associated with a significant decrease in risk of neck/shoulder symptoms at the age of 34 in men, but not women. Women attain 50- 80% of the neck strength of men.34-36. Another study Mikkelsson (2006) found that higher endurance strength in boys predicted lower occurrence of neck/shoulder pain in adulthood, and higher strength in adolescent girls predicted lower occurrence of low back pain.3 In women, high endurance strength predicted low occurrence of tension neck, whereas in men it was a predictor of knee injury.
Section 5 – Importance of testing
The most common causes of morbidity and mortality are coronary heart disease, stroke, obesity, hypertension, type-2 diabetes, allergies and several cancers. A sedentary lifestyle is a major risk factor for these diseases and is close to overtaking tobacco as the leading cause of preventable death (Ruiz et al, 2006). The protective effect of intentional physical activity on the above mentioned non-communicable diseases has been widely reported in people of all ages (Strong et al. 2005). Regular participation in moderate and vigorous levels of exercise increases physical fitness, which can lead to many health benefits (Figure 2) (Ruiz et al, 2006). Physical fitness testing therefore can play an important role in firstly identifying potential health risk in individual adolescents and secondly promoting physical activity and educate adolescents in the importance of keeping fit and active. Sport scientists can potentially help in the area of health promotion. The promotion of physical activity is a key area which needs to be examined. Sport scientists could take up this role and potentially provide education to adolescents on both the benefits associated with remaining physically active and the risk factors previously mentioned with sedentary behaviour.
Section 6 – Conclusion
A common theme and one conclusion which several papers resulted in stating results and experiences obtained from research suggest that physical fitness is a key health marker in children and adolescents. The fitness tests to be included in the assessment of health-related fitness in the fitness battery tests seem to give relevant information regarding the health status of the young people and rightly focus on the various specific components of health e.g. cardiovascular fitness. The specific fitness tests are chosen due to their practicality and low cost. Validation studies of most of these tests have already done (Ruiz et al, 2006) and results have found them to be quite valid and reliable. Future health information systems should include monitoring of health-related fitness among adults as well as among young individuals, and results and experiences from recent and ongoing research projects on young people across the globe should be taken advantage of. Development of efficient systems for large-scale collection of health-related fitness data and transfer of data to centrally located databases will be the next major step in the area of mass physical fitness testing (Ortega, 2007).
Section 7 – Appendix
Graph 1 – Relation between lean tissue mass (LTM) measured by Dual-energy X-ray absorptiometry (DXA) and lean body mass (LBW) by Bioelectrical impedence analysis (BIA). The line represents the regression line B: Difference between LTM by DXA & LBM by BIA (Boot et al, 1997)
Graph 2 – Association between cardiovasvular profile (calculated from age & gender specific standardised values of triglycerides, LDLs, HDLs & fasting glycemia) And CRF values in non-overweight adolescents (Gonzalez et al, 2003).
Table 1 -Additions & Deletions to the FitnessGram tests
Table 2 – Summary of fitness tests in Europe by the HELENA study (2008)
Figure 1 – FitnessGram Results Sheet
Figure 2 – The association between adolescent physical activity and heath possible pathways
Section 8 – References
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Eurofit Fitness Test battery available at: http://www.topendsports.com/testing/eurofit
Feldman, D.E., Shrier, I., Rossignol, M., Abenhaim, L. (2000). Risk Factors for the Development of Low Back Pain in Adolescence. American Journal of Epidemiology. 154 (1), 30-37.
Fitnessgram test battery available at http://www.fitnessgram.net
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