The effect of varying plyometric volume on stretch-shortening cycle capability in collegiate male rugby players
The purpose of this study was to identify the effectiveness of low and high volume plyometric loads on developing stretch shortening cycle capability in collegiate rugby players. A between- group repeated measures design was used. Thirty six subjects (age 20.3 ±1.6 yrs, mass 91.63 ±10.36kg, stature 182.03 ±5.24cm) were randomly assigned to one of three groups, a control group (CG), a low volume plyometric group (LPG) or a high volume plyometric group (HPG). Data were collected from a force plate, and measures of reactive strength index (RSI) and leg stiffness were calculated from jump height, contact time and flight time. A significant between group × time (F = 4.01, P <0.05) interaction effect for RSI was observed. Bonferroni post hoc analysis indicated that both the LPG training group (P = 0.002) and HPG training group (P = 0.009) were significantly higher than the control group. No significant interaction effect between time × group were observed for leg stiffness (F = 1.39, P = 0.25). The current study has demonstrated that it is possible to improve reactive strength capabilities via the use of a low volume plyometric program. The low volume program elicited the same performance improvement in RSI as a high volume program whilst undertaking a lower dose. This suggests that strength and conditioning coaches may be able to benefit from the ability to develop more time efficient and effective plyometric programs.