<p><b>ABSTRACT</b></p>
<p><b>BACKGROUND:</b> Little is known on how relocations of
time spent in different movement behaviours during pre-school hours could
relate to preschooler’s fundamental movement skills (FMS), a key predictor of
later physical activity (PA). Thus, the aim of this study was to examine whether
the school-time composition was associated with FMS; and to investigate
predicted differences in FMS when a fixed duration of time was reallocated from
one activity behaviour to another in preschool children. <b>METHODS:</b> A cross-sectional
representative data of an intervention study with Brazilian low-income
preschoolers. Two hundred and four preschoolers of both sexes (4.5±0.8
years-old; 101boys) provided 10 hours of school-time objectively assessed PA
and sedentary behaviour (SB) data (Actigraph wGT3X), and FMS assessments
(TGMD-2). Association of school-time composition of movement behaviuors with
FMS and its reallocations during school-time was explored using compositional
analysis in R (version 1.40-1), robCompositions (version 0.92-7), and lmtest
(version 0.9-35) packages. <b>RESULTS:</b> The isotemporal reallocation showed that
for manipulative skills, an increasing pattern was observed (0.14, 0.28,
and 0.42-units) when reallocating 5, 10 and 15 minutes, respectively, from light
PA to SB. <b>CONCLUSIONS:</b> The current study highlights that school-time
composition is a significant predictor of FMS. Moreover, a modest increase in SB,
at the expense of LPA, during the school-time may elicit a positive change in
manipulative skills. </p>