Physical fitness level in Italian high-school adolescents: a cross-sectional study

IntroductionPhysical activity is known to be an important factor in the promotion of people's health and physical efficiency (U.S. Department of Health and Human Services, 2010; Janseen & LeBlanc, 2010). Participating in a regular physical activity has been associated with several health benefits (Biddle et al., 2004), nevertheless, young people's physical inactivity, in conjunction with high prevalence of overweight, obesity and sedentary behaviour, has been found to be the main threat to health in the twenty-first century (Blair, 2009). Physical fitness has been defined as the result of body movement generated by muscles' action which increase expenditure of energy (McArdle et al., 2001). It has been erroneously defined as a synonym of aerobic fitness rather than being considered a definition that embraces all components concerning health (Hands et al., 2009). Indeed, it includes different components such as endurance, strength, flexibility, coordination, balance (Knapik et al., 2006). Physical fitness represents the best index of health condition at any age (Ortega et al., 2008). It has been positively associated with benefits on cardiovascular system, levels of total and abdominal adiposity, skeletal apparatus, depression, anxiety, self-esteem and school achievement (Catley & Tomkinson, 2013; Van Dusen et al., 2011; Ortega et al., 2008). Childhood and adolescence represent crucial moments of life, when lifestyle and healthy or unhealthy behaviour determined at this age may affect health condition in adulthood (Ortega et al., 2008). It has been demonstrated that physical fitness is determining of lifestyle in connection with motor performance as well as individual health condition, and this information has produced much evidence on variation of this aspect in adolescents (Catley & Tomkinson, 2013; Dyrstad et al., 2012; Sandercock et al., 2012; Marta et al., 2012a,b; Sauka et al., 2011). A number of researches reported that today children are not physically active as their peer were in past decades (Dyrstad et al., 2012; Huotari et al., 2010), although other Authors did not notice any difference (Malina, 2007; Jurimae et al., 2007). Some researches have pointed out that annual decrease of physical fitness is about 0,36% since 1970 (Hardly et al., 2007). A study carried out on Finnish adolescents reported a reduction of aerobic fitness of 6-10% between 1976 and 2001 for boys and girls aged 13-18 (Huotari et al., 2010), whereas they found no difference in Danish adolescents aged 15 to 19 in terms of maximum oxygen consumption during 1983,1997 and 2003 (Andersen et al., 2010). A recent study indicated that in Norwegian teenagers between 1980 and 2000, the annual rate of decline in aerobic fitness is 0.50% for boys and 0.36% for girls (Dyrstad et al., 2012). Some researchers have confirmed this trend: they have shown a decrease in aerobic fitness in both sexes among English young people and they pointed out that 27.1% of boys and 19.8% of girls do not follow the international recommendations (Sandercock et al., 2012). The analysis of components such as muscular strength, speed and flexibility did not show a homogeneous trend (Luguetti et al., 2010; Albon et al., 2010; Jurimae et al., 2007). A review analysing speed and strength performance in children (aged 6-12) from different countries between 1958 and 2003, revealed it is emerging a new negative trend since 1980 (-0.08% - -0.25% per year), even though values for these abilities resulted stable during that period (Tomkinson, 2007). Analysing performance of children aged 7 to 16 years in 9-minute run, standing broad jump, medicine ball throw and 1-minute curl-up, some researchers have drawn attention to a reduction (often over 50%) of performance in all tests, for both sexes, particularly girls (Luguetti et al., 2010). Whereas a recent study showed that Spanish adolescents improved performance in 4x10m and 20m shuttle run test and they worsened performance in hand grip test and standing broad jump comparing 2001-2002 and 2006- 2007 (Moliner-Urdiales et al. …