ABSTRACT
The terms growth, development and maturation are used interchangeably when describing the pathway from birth to adulthood. There is much debate over the definition of these terms but each refers to specific biological activities. Generating operational definitions for these terms will help clarify the subsequent discussion and debate. Growth is the most significant biological activity during the first 20 years or so of life, starting from conception to full maturity. Tissue growth occurs within body parts and results in a quantitative increase in body mass and stature. These changes
are a result of a combination of hyperplasia, hypertrophy and accretion leading to an increase in cell number, size and cellular material respectively. Hyperplasia, hypertrophy and accretion are significant cellular processes that drive growth. These processes are not linear, for example the number of cells (hyperplasia) is largely determined during the pre-natal period whereas hypertrophy follows a non-linear pathway through childhood to adulthood. Maturation is the process of becoming mature. The timing and tempo of maturation varies between biological systems. For example, sexual maturity is defined as a fully functional reproductive system, compared to skeletal maturity which refers to a fully ossified skeleton; the timing and tempo of both can differ significantly. Timing defines ‘when’ a particular maturation process occurs whereas tempo is the ‘rate’ at which maturation progresses. As we will note later the timing and tempo of stature are highly individual and are also different between girls and boys. In essence, growth is a quantitative increase in stature or size at any given time, compared to maturity which is the rate of progress to full adult stature or mature state. Clearly growth and maturity are inextricably linked and are processes that are measurable and directional. Development is a broader concept than growth and maturation. It is generally viewed as qualitative, involves differentiation of tissues and is both biological and behavioural. The biological differentiation of cells to form specific tissues, organs and body systems occurs in the embryonic and fetal stages of the pre-natal environment and differentiation of a tissue is complete when it becomes functional. This development continues in the post-natal environment as the function of the body systems and tissues becomes refined. Behavioural development reflects a period of change in the psychomotor (fitness, skills), cognitive (knowledge, understanding) and affective (social, relationships) domains. As children interact with society their ability to express themselves in these domains becomes refined and their intellectual, physical, social and moral competencies mature. The strength and conditioning coach should not only consider the physical consequences of the interaction of training with growth, maturation and development, but also the important impact of behavioural development and whether training provides a positive educational experience for youths.
