Self-Rated Health (SRH) is a relevant construct for a healthy lifestyle and is used to capture a person’s perception of their overall health status [1
]. Epidemiological studies and health surveys highlight perceived heath or SRH, defined as the self-assessment that the population or an individual makes of their health condition as a product of their knowledge and own interpretations without necessarily representing a clinical diagnosis by the professional health staff [2
]. Normally, this indicator is used in population surveys and in censuses of small populations or very specific collective groups [4
]. Although, this measurement is subjective, previous studies have shown a close relation between SRH and other physical and mental health outcomes [3
The association between physical fitness and SRH among adolescents may differ according to sex and overall level of physical activity, i.e., the association is stronger among boys and among more physical inactive adolescents [5
]. Individuals’ perceptions of their health incorporate psychological, biological, and social dimensions that are unavailable to the external observer, but also provide a dynamic assessment of their current health status while integrating their health history [5
]. For example, Idler and Benyamini [6
] showed in a narrative review including 27 observational studies that SRH was related to objective health and was conditioned by the recent evolution of individual skills. In populations with poor access to health services, such as school-aged children, SRH studies have been better at showing the burden of the disease than medical records [7
]. In the early stages, a study of 1155 Swedish children between 6 and 13 years of age by Petersen et al. [8
], found that 23% of the children self-reported weekly recurring headaches, 19% stomach aches, and 18% back pain. In Colombia, Higuita-Gutiérrez et al. [9
] performed a study with 3452 adolescents and highlighted that 10% of participants reported eye diseases, 3.1% participants reported diseases of the respiratory system, and 1.1% participants reported diseases of the musculoskeletal system.
In addition, SRH has been associated with low socioeconomic level, gender (women), lower education level, use of medical services, and poor lifestyle [10
]. Regarding lifestyle, Kujala et al. [12
] stated that healthy lifestyles influence an individual’s perceived health, which is why its absence could be related to the early onset of physical symptoms and future diseases. Thus, a relationship has been described between SRH and the physical condition related to health [13
], suggesting that an active lifestyle as well as good cardiorespiratory fitness probably increase self-rated health.
Physical fitness, especially the cardiorespiratory component, is considered an important health indicator in children and adolescents [14
]. Previous studies by Janz et al. [15
] and Castillo-Garzón et al. [16
] showed that a low cardiorespiratory fitness (CRF) level during childhood was associated with a higher risk of cardiovascular and metabolic disease during adulthood. Moreover, it has been described that a lower CRF level in children and adolescents from 9 to 17 years of age is a predictive factor of physical well-being in school-aged children [17
]; hence, including this health indicator in epidemiological surveillance systems at the educational level is clearly justified [19
Similarly, a cross-sectional study carried out by Herman et al. [20
] with Canadian school-aged children displayed that higher levels of physical activity are directly related to better SRH and a healthy nutritional status. A study by Becerra et al. [21
], which included 264 adolescents from Málaga (Spain), reported an inverse relationship between peak oxygen consumption (VO2
peak) and symptoms such as pain and/or fatigue (r = −0.40; p
< 0.001) as well as anxiety and insomnia (r = −0.46; p
< 0.001). Recently, a prospective study with over 16 years of follow up conducted by Kantomaa et al. [22
] in a sample of 7063 Finnish adolescents established that a better SRH was associated with a healthier level of CRF in both sexes.
Greater knowledge of SRH in children and adolescents, as well as its relationship with physical fitness parameters, could prevent future associated health risks in this population. Hence, this study sought to evaluate the relationship between SRH and CRF in a sample of children and adolescents enrolled in official schools in Bogotá, Colombia participating in the FUPRECOL (Asociación de la fuerza prensil con manifestaciones de riesgo cardiovascular tempranas en niños y adolescentes colombianos in Spanish) study. We hypothesized that high levels of CRF are associated with rare or absent symptoms among schoolchildren.
The most relevant finding in this study was that boys and girls categorized with unhealthy CRF had higher odds of problems “more than once a week” and “almost every day” than healthy counterparts in the eight questions from the SRH questionnaire. As should be expected when considering such SRH, the occurrence of subjective physical complaints was relatively low in our study, with irritability/bad mood being more frequently reported, followed by headaches.
The perception of stomach-ache was higher in girls compared to boys, as previously reported [7
]. Subjective indicators of health markedly differ between youth in different countries, although multiple complaints are generally declared at higher proportions in girls compared to boys. From current evidence, the relationship between physical fitness and SRH in a young population is still scarce and confusing, as well as contradictory when comparing both genders [29
]. This study found significant differences in the self-reporting of sensed morbidity, finding that girls presented higher prevalence of irritability/bad mood, while boys presented higher prevalence of feeling-low. Prior studies concluded that girls tend to endure 2–3 times more self-reported health problems than boys [29
]. Regarding this finding, Johnson and Richter [30
] considered that SRH is an adequate indicator of real health, highlighting that girls are often more pessimistic than boys, since they tend to self-report more serious problems related to their health. This fact also coincides with the indirect estimation of CRF because girls with unhealthy CRF showed higher frequencies of somatic problems compared to boys.
A previous study has found relationships between SRH and backache, with low levels of physical activity (<6 h per week) especially in adolescent girls [31
], but the physical fitness was not analyzed. In this study, the frequency of reporting experiencing this symptom “almost every day” was higher in girls (4.4% boys, 6.0% girls, p
< 0.05). The importance of the study of back pain in young people is remarkable since the early appearance of this symptom is a risk factor related to pain in adulthood [32
]. Another symptom in the young population that has gained importance in the scientific literature is headache [33
], which is additionally associated with poor physical condition [34
]. In our study, this factor occurs in girls and boys at frequencies of 12.1% and 6.9%, respectively. Reports show that youth with low levels of physical activity have a higher risk of suffering from frequent headaches [34
]. In school-aged children, a recent study published by Vierola et al. [35
] revealed that infants with low CRF were 1.95 times more prone to suffering from headaches than infants with healthy values of aerobic fitness, independent of physical activity levels. Unfortunately, we were not able to measure variables related to physical activity levels in the FUPRECOL sample. Additionally, increasing sedentary behaviors, like screen time, have been directly associated with greater presence of musculoskeletal pain and lower self-perception of health, especially in males younger than 12 years of age [36
]. This finding is relevant and coincides with our results since reports indicate that these types of diseases are associated with symptoms like cephalea, which may even affect the student’s academic performance [37
Other symptoms reported in our study were irritability/bad mood, nervousness, and feeling-low, which to our knowledge have not been studied well in this population nor have their associations with physical fitness. However, we may speculate that the presence of some of these risk factors can be associated with other unmeasured factors related to morbidity, which seem particular to this age stage, characterized by high family and school demands; nonetheless, this requires further research [38
]. In this sense, Hernan-Gómez et al. [39
] propose that adolescence may bring diminished positive emotions and decreased vital satisfaction with a gradual increase of negative emotions that could affect the SRH. This finding coincides with that reported by Urzúa [40
], who wrote that adolescent girls have the worst perception with respect to their health, with physical well-being and particularly their perception of themselves being the two dimensions with the least favorable evaluation. This perception of themselves constitutes a warning signal for health authorities, given that it could be indicating dissatisfaction of women with their own bodies and, hence, a higher risk of the onset of inadequate nutritional habits [41
]. In synthesis, the lower SRH during the school stage could certainly be related to the complexity that characterizes this stage of development, especially in girls from Bogotá, Colombia.
To date, there are few studies that have analyzed the association between SRH and fitness in a young population, including the cardiorespiratory capacity. Häkkinen et al. [42
] found a direct association between SRH, physical activity and CRF in a study of 727 youths. This study shows that healthy values of CRF increased the self-perception of well-being and organic health. In keeping with this, Kantoma et al. [5
] showed that SRH measured as the question: how do you consider your state of health? And the CRF, estimated using a cycle-ergometer, was associated with better scores in the SRH in Colombia, which is a result that agrees with our study. We found that an unhealthy CRF in children and adolescents is a predictive factor of physical well-being [17
]. It is important to delve into the components of SRH to detect risk factors associated with enduring future diseases with the aim of implementing different interventions with a perspective of primary health care.
The mechanism between SRH and better CRF is not well established. One plausible explanation relates to the afferent information that conveys messages from the organism to the brain [43
]. These messages are usually not brought to consciousness because they function at lower levels of the central nervous system. Another theory explaining a person’s perceptions of their health involves a family of proteins called cytokines [44
]. Research is beginning to show that the subclinical inflammatory process and certain cytokines are associated with tiredness, depressive mood, pain, irritability, and poor appetite [45
This study contained a series of limitations that must be described. The first limitation is inherent to its cross-sectional nature and type of sampling, which does not permit evaluating causality relationships. Second, it would be fitting to broaden the population object of study to different age brackets or private establishments. The reason for having selected a sample between 9 and 17 years of age is due to the variability we can find in physical activity habits during these ages. Third, the study did not evaluate levels of physical activity of the youth, factors that can modulate the results of this work. Fourth, although the evaluation of CRF in children and adolescents was carried out through a valid and standardized test in this population [19
], we must bear in mind that the CRF is partially genetically determined [46
]. A previous study [47
] has tested the degree of agreement between various equations used to estimate VO2
peak and the actual VO2
peak. The equation used to estimate VO2
peak in this study may have underestimated CRF by up to 12% relative to other methods and therefore may have, in isolation, inflated the prevalence of unhealthy aerobic capacity [18
]. Therefore, we considered our low CRF estimates to be conservative. Furthermore, cutoffs proposed were very like the interim international criterion-referenced standards of 35 and 42 ml·kg−1
for girls and boys, respectively, to identify children and youth at risk of poor health, raising a clinical red flag [18
]. However, there are no arguments to believe that the relationships described occur exclusively in the population from our sample, given that we observed convergence of the results with data described in other national and international studies [29
], hence, the results obtained herein are not compromised.
The strengths of this research broaden the scope regarding SRH in children and adolescents because both age groups were included and the methods used did not refer to specific diseases, like diabetes and myopia, as reflected in other studies [2
]. To our knowledge, this is the first study to demonstrate positive associations of CRF with SRH in Latin-American schoolchildren in a large birth cohort with objective measurements of CRF. Another strength of this study lies in the large, unselected population sample. Furthermore, it approaches specific symptoms and their frequency, which permits better guidance of the specific health needs of children and adolescents from the Latino population. Nevertheless, longitudinal studies are needed to measure other confounding factors that can interfere with the interpretation of the results, like ethnicity, socioeconomic level, physical activity levels, etc.