Physical fitness of elite women's rugby union players over a ...

now common practice to monitor sum of skinfolds in elite rugby players in preference to
estimating percentage body fat, as it can be used to monitor changes in peripheral fat stores
over time (Jenkins & Reaburn, 2000).
The skinfold thickness is reported to significantly higher in forwards than backs for male
professional rugby union players (forwards: 84 ± 19 mm vs. backs: 60 ± 13mm), and elite
female rugby league player (forwards: 141 ± 37.2 mm vs. backs: 114.8 ± 20.2 mm) (Duthie,
2006; Gabbett, 2007). It has been suggested that the higher percentage body fat in forwards
may serves as protective buffer in contact situations or impact injuries (Bell, 1973), however,
to date no conclusive evidence exists to support or refute this claim. The lower body fat values
of the backs are a reflection of the higher speed requirements of these players. Body fat values
for male backs are said to be similar to other team sports such as field hockey, soccer and
touch rugby (Duthie, Pyne & Hooper, 2003). Excessive body fat should be avoided as it has
shown to have negative impact on performance for two main reasons, First, Newton’s second
law (a = F/m) specifies that increases in fat mass (m) without an increase in muscle force (F)
will reduce acceleration (a). Second, displacement of additional fat mass requires extra
energy, which increases the relative physical cost of exercise (Duthie, 2006).
2.4.4 Speed
Speed is a component of fitness that is often assessed by sport scientist to indicate athletic
ability (Logan, Fornasiero, Abernethy, & Lynch, 2000). Speed is the ability to cover distances
in as short a time as possible and represents the maximum capabilities of an athlete in a
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