Page 136 - Petelin Ana. Ur. 2022. Zdravje otrok in mladostnikov / Health of children and adolescents. Proceedings. Koper: Založba Univerze na Primorskem/University of Primorska Press
P. 136
avje otrok in mladostnikov | health of children and adolescents 136 Introduction
Physical fitness is an indicator of health in youth and is related to later body
composition in preschool age (Henriksson et al., 2019). The obesity epidemic,
at one time confined to adults, has now penetrated the pediatric age range and
shows every sign of a rapid escalation (McCarthy et al., 2006). Studies examin-
ing the association of health-related physical fitness and total and central body
fat in a population of preschool children as young as 3 to 5 years old are scarce
and mainly measured by one fitness test. Research data Martinez‐Tellez et al.
(2016) shows that excess body fat in preschool children results in poorer per-
formance on all tests that require bodyweight movement. Explosive power is
the ability to activate the maximum number of movement units in the short-
est possible time, it appears as the maximum initial acceleration when mov-
ing the body in space (Pistotnik, 2011). It is characterized by the rapid produc-
tion of a large amount of muscle power in a very short time. It manifests itself
mainly in acyclic movement types of jumping, throws and kicks, and in short
sprints (Pistotnik et al., 2002). Direct online control of movement is not possi-
ble without fast, explosive and instantaneous movements. This is done on the
basis of sensory information at different levels: spinal cord, brain stem, subcor-
tical centers and sensory-motor centers in the cerebral cortex. For preschool
children engaged in an additional form of organized physical activity, the in-
fluence of morphological characteristics on the expression of strength is less
obvious compared to children who do not have organized additional physi-
cal activity, primarily due to the reduction of subcutaneous fat and body mass
as disruptive factors (Sadri et al., 2014). Appropriately designed and controlled
strength training is safe for children, contributes to increasing muscle strength,
better performance of other sports movements and reduces susceptibility to in-
juries. Such a method also improves the general health status of the child and
has a positive effect on the psychosocial component of the child (Škof, 2016).
Methods
A causal non-experimental method was used to obtain the data. The sample
consisted of 5-6-year-old children of both genders (N=75), divided into three
groups based on body mass index (WHO BMI for age 5-19 years) – Normal-
weight (N=54), Overweight (N=5) and Obese (N=16). The number of children
in each BMI group was not balanced. The explosive power of the legs was meas-
ured with two motor tests – a long jump from the site and counter movement
jump tests on the ARS force plate. Muscle and fat mass were measured with
a Tanita DC 430-MA body composition analyzer. 1-way analysis of variance
(ANOVA) with eta squared values for effect size, was used to compare the re-
sults between groups and Pearson correlation was used for assessing relation-
ship between outcome variables.
The values of fat and muscle mass represent the independent variables.
Explosive power, expressed as the average Z-value of the two motor tests, rep-
resents the dependent variable.
Physical fitness is an indicator of health in youth and is related to later body
composition in preschool age (Henriksson et al., 2019). The obesity epidemic,
at one time confined to adults, has now penetrated the pediatric age range and
shows every sign of a rapid escalation (McCarthy et al., 2006). Studies examin-
ing the association of health-related physical fitness and total and central body
fat in a population of preschool children as young as 3 to 5 years old are scarce
and mainly measured by one fitness test. Research data Martinez‐Tellez et al.
(2016) shows that excess body fat in preschool children results in poorer per-
formance on all tests that require bodyweight movement. Explosive power is
the ability to activate the maximum number of movement units in the short-
est possible time, it appears as the maximum initial acceleration when mov-
ing the body in space (Pistotnik, 2011). It is characterized by the rapid produc-
tion of a large amount of muscle power in a very short time. It manifests itself
mainly in acyclic movement types of jumping, throws and kicks, and in short
sprints (Pistotnik et al., 2002). Direct online control of movement is not possi-
ble without fast, explosive and instantaneous movements. This is done on the
basis of sensory information at different levels: spinal cord, brain stem, subcor-
tical centers and sensory-motor centers in the cerebral cortex. For preschool
children engaged in an additional form of organized physical activity, the in-
fluence of morphological characteristics on the expression of strength is less
obvious compared to children who do not have organized additional physi-
cal activity, primarily due to the reduction of subcutaneous fat and body mass
as disruptive factors (Sadri et al., 2014). Appropriately designed and controlled
strength training is safe for children, contributes to increasing muscle strength,
better performance of other sports movements and reduces susceptibility to in-
juries. Such a method also improves the general health status of the child and
has a positive effect on the psychosocial component of the child (Škof, 2016).
Methods
A causal non-experimental method was used to obtain the data. The sample
consisted of 5-6-year-old children of both genders (N=75), divided into three
groups based on body mass index (WHO BMI for age 5-19 years) – Normal-
weight (N=54), Overweight (N=5) and Obese (N=16). The number of children
in each BMI group was not balanced. The explosive power of the legs was meas-
ured with two motor tests – a long jump from the site and counter movement
jump tests on the ARS force plate. Muscle and fat mass were measured with
a Tanita DC 430-MA body composition analyzer. 1-way analysis of variance
(ANOVA) with eta squared values for effect size, was used to compare the re-
sults between groups and Pearson correlation was used for assessing relation-
ship between outcome variables.
The values of fat and muscle mass represent the independent variables.
Explosive power, expressed as the average Z-value of the two motor tests, rep-
resents the dependent variable.
