Relationships of BMI, muscle-to-fat ratio, and handgrip strength-to-BMI ratio to physical fitness in Spanish children and adolescents

Abstract

This study aimed to determine the relationship of body mass index (BMI), muscle-to-fat ratio (MFR), and handgrip strength-to-BMI ratio to physical fitness parameters in an active young population according to sex across four different time points. A total of 2256 Spanish children and adolescents (aged 5–18) from rural areas participating in an extracurricular sport in different municipal sports schools participated in this study. Participants were divided into children (5–10 years) and adolescents (11–18 years), boys and girls, and across four different time points (2018, 2019, 2020, 2021). Data on anthropometric measures (BMI, MFR, appendicular skeletal muscle mass) and physical fitness (handgrip strength, cardiorespiratory fitness, and vertical jump) were collected. Boys who were overweight, but especially boys with obesity, had higher absolute handgrip strength in children and adolescents than their normal weight counterparts in 2020 and 2021. Boys and girls with normal weight presented higher cardiorespiratory fitness and vertical jump than their overweight and obese peers over the years. The MFR was directly correlated with the cardiorespiratory fitness and vertical jump variables, but not with handgrip strength, in boys and girls. The handgrip strength-to-BMI ratio in both sexes was positively correlated to the different physical fitness parameters. Conclusion: BMI, MFR, and handgrip strength-to-BMI can be used as health and physical fitness indicators in this population. What is Known:• BMI is the main indicator commonly used as a proxy for obesity for many years. Nevertheless, it cannot differentiate between fat mass and fat-free mass.• There are other indicators such as MFR and handgrip strength-to-BMI that might be more accurate and can serve to monitor the health and fitness of children and adolescents. What is New:• MFR showed a positive and significant correlation with cardiorespiratory fitness and vertical jump in both sexes. On the other hand, the handgrip strength-to-BMI presented a positive correlation with cardiorespiratory fitness, vertical jump, and handgrip strength.• The use of these indicators obtained through different parameters of body composition and physical fitness can serve as a tool to identify the relationships of the paediatric population with physical fitness.

The relationships between body mass index, reciprocal ponderal index, waist-to-height ratio, and fitness in young adult males

“…In terms of the 6 min walk and VAM-EVAL tests, the best predictor was BMI. These findings are in line with previous results ( Manzano-Carrasco et al, 2023 ). Considering the importance of cardiorespiratory fitness levels for health in the young adults males ( Ortega et al, 2018 ; Agostinis-Sobrinho et al, 2022 ), BMI might be considered as a predictor of aerobic fitness tests.…”

“…BMI has been widely used to quantify body fat and identify people who are overweight ( Qin et al, 2022 ) which have negative consequences for the health of children (e.g., dyslipidemia, arterial stiffness, and less cardio-respiratory capacity) ( Vaara et al, 2013 ; Abdelkarim et al, 2020 ) and adults (e.g., risk of heart attack) ( Jafari et al, 2019 ). Several studies have identified that a high BMI is related to poor cardiorespiratory fitness and vertical jump ( Qin et al, 2022 ; Manzano-Carrasco et al, 2023 ), which is linked to effects by the kind of sport done on physical fitness ( Tahira, 2021 ). In this sense, regular sport participation could be a great strategy to increase fitness and combat the consequences of high BMI ( Tahira, 2021 ).…”

Eating Behavior and Factors of Metabolic Health in Primary Schoolchildren: A Cross-Sectional Study in Greek Children

“…VO 2 max is directly correlated with HGS, a strong predictor of cardiovascular health in both young adults and children [ 13 , 14 , 16 ]. Recently, children with overweight/obesity showed higher HGS and lower CRF compared to their normal weight counterparts [ 16 , 56 ].…”

“…There is now evidence that low HGS may be associated with poor cardiometabolic outcomes in children and adolescents too [ 15 ]. In a recent observational study in 2256 children and adolescents aged 5–18 years, HGS-to-body mass index (BMI) presented a positive correlation with cardiorespiratory fitness [ 16 ].…”

Mediation effects of lean mass and fat mass on the relationship between body mass index and handgrip strength

“…HGS has been widely investigated for its relationship with disease prevalence and associated factors in the adolescent population in order to identify groups more prone to low levels of muscle strength (Bim, Pinto, Scarabelot, et al, 2021; Ng et al, 2019; Silva et al, 2017). Body mass index (BMI) was found to be directly related to HGS, indicating that adolescents with overweight (including obesity) have higher HGS (Bim, Pinto, Scarabelot, et al, 2021; Bim, Pinto, Silva, et al, 2021; Manzano‐Carrasco et al, 2023; Ng et al, 2019; Silva et al, 2017). This finding, however, is controversial because, when HGS is normalized to body weight, the association with obesity indicators seems to change direction (Lima et al, 2022).…”