Thesis-2004-Murdey.pdf (4.49 MB)
Pubertal development and sedentary behaviour during adolescence.
thesis
posted on 2013-11-12, 13:27 authored by Ian MurdeyThe objective of the current study was to investigate the relationships between
changing pubertal status, body composition, body image, and time spent in sedentary
behaviours during adolescence. A mixed-longitudinal design was used involving 119
students from school Years 6 (10.0 - 10.9 years of age), 8 (12.0 - 12.9 years) and 10
(14.0 - 14.9 years). Participants were assessed in three phases carried out at six-month
intervals.
Cross-sectional results from Phase 1 showed that time spent in sedentary behaviours
was significantly greater in participants who had started puberty compared with those
who were pre-pubertal, and in those who were late-/post-pubertal compared with
those who were pre-/early-pubertal. Also, students in Year 10 spent significantly
greater time in sedentary behaviours compared with those in Years 6 and 8. These
differences disappeared after controlling for the amount of time spent sleeping except
for the Year 10 boys. It was concluded that differences in sedentary behaviour during
adolescence were not associated with differences in behavioural choice related to
greater maturity per se but to a greater opportunity for such behaviours with more
waking hours.
Longitudinal analysis examined changes between Phases 1 and 3. Analysis of
covariance showed that, for boys only, weekday sedentary behaviour increased by a
significantly greater amount for participants who increased puberty compared with
those who stayed at the same pubertal level. No differences were found between
pubertal groups for either gender during the weekend. No significant correlations were
found between changing body composition and changing body image for boys or girls
or between the change in pubertal status and change in body composition or body
image. Multiple regression analysis showed that a significant amount of the variance
of the increase in weekday sedentary behaviour could be explained by increased
pubertal status for boys and reduced physical attractiveness for girls. When
considering increasing weekend sedentary behaviour an increase in percentage body
fat explained a significant amount of the variance for girls. It was concluded that only
a part of the a priori hypothesis, that changes in sedentary behaviour are associated
with pubertal changes, was supported by this data and that any changes found were
not associated with behavioural choices triggered by body compositional changes.
History
School
- Sport, Exercise and Health Sciences
Publisher
© Ian MurdeyPublication date
2004Notes
A Doctoral Thesis. Submitted in partial fulfilment of the requirements for the award of Doctor of Philosophy of Loughborough UniversityLanguage
- en