European Journal of Physical Education and Sport Science

Number 9, 2017

11
EFFECT OF WEIGHTED JUMP WARM-UP ON VERTICAL JUMP IN FEMALE VOLLEYBALL PLAYERS

Authors: Deneke N., Sevene T. G., DeBeliso M., Luke R., Berning J. M., Adams K. J.

Abstract

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Warm-ups which elicit a post activation potentiation (PAP) effect may increase performance in subsequent activities requiring strength and power. However, finding practical methods to best manipulate and exploit PAP remains elusive. Purpose: To determine if a warm-up that included weighted jumps would elicit a PAP effect and increase subsequent vertical jump (VJ) height. Methods: Ten female NCAA Division II volleyball players participated (age = 19.8 ± 1.8 yrs; mass = 71.7 ± 9.7 kg; ht = 167.8 ±23.9 cm). Two warm-up conditions were randomly employed: 1) light jogging, high knees, carioca, shuffling, ankle pops, pogos, and tuck jumps; and 2) an identical warm-up, plus 10 maximal VJs while wearing 20% of bodyweight. At 4-minutes post, VJ was randomly assessed in two conditions: 1) 2-hand standing block VJ (SBVJ), and 2) 1-hand 3-step approach VJ (AVJ). Paired Samples T-test determined if there was a significant difference (p < 0.05) in VJ height between the two conditions. Results: Results were mixed. No significant difference (p > 0.05) occurred in the SBVJ (262.1 vs. 263.0 cm, warm-up vs. warm-up with weight vest, respectively). However, the AVJ was significantly higher by 2.7±1.5 cm (p < 0.05; 275.1±13.2 vs. 277.8±13.2 cm) with the weight vest added to their warm-up. Conclusion: This study demonstrates that a dynamic warm-up with the addition of weighted jumps may increase 3-step AVJ ability in female collegiate volleyball players. However, no effect was seen in 2-hand SBVJ ability. Coaches may consider using a warm-up that includes weighted jumps to optimize performance in sports like volleyball where vertical jumps with an approach are key components of competition.

12
CONTINUOUS WEIGHTED JUMPING: EFFECTS ON VERTICAL JUMP HEIGHT

Authors: Sevene T. G., DeBeliso M., Carson C., Berning J. M., Harris C., Adams K. J.

Abstract

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High intensity, near maximal exercise is a conditioning activity which can cause neural hyper-stimulation and lead to acute enhanced power production known as post-activation potentiation (PAP). Investigations need to be conducted to better understand the duration and intensity of the conditioning activity and subsequent effects on the fatigue-potentiation relationship. Purpose: To investigate the effect of 30 seconds of continuous vertical jumping while wearing a vest loaded with 30% of body weight on power output as measured with a maximal vertical jump (VJ). Methods: 14 volunteers (8 weight trained males [23.0+2.9 yrs, 79.8+13.8 kg, 179.9+8.6 cm] and 6 weight trained females [23.0+2.9 yrs, 69.9+13.3 kg, 171.6+7.0 cm]) participated in the study. Pre-testing consisted of each participant performing 3 VJs. The highest VJ was recorded as baseline. A weighted vest was then loaded equaling 30% of the individual's body weight; while wearing the weighted vest, participants performed 30 seconds of continuous VJs. Immediately after jumping participants were seated in a chair for 3 minutes; at 3 minutes, they performed a maximal VJ without the weighted vest in the same manner as done during pre-testing. Two additional VJs were repeated at 4 and 5 minutes post weighted jumping. A mixed design ANOVA with repeated measures was performed. Results: Results showed main effects for each of the independent variables tested, gender and jump. The posttest values at all 3 intervals for both males and females were significantly different from the pretest scores (F [3, 36] = 21.74, p < 0.05). Post hoc analysis indicated that the pretest VJ scores (M = 280.1±18.6 cm) decreased significantly at the 3 minute interval (M = 278.1±18.3 cm), followed by a significant increase in height at the 4 minute interval (M = 281.1±18.7 cm), and another increase at the 5 minute interval (M = 283.0±19.2 cm). Males jumped significantly higher than the females across all trials (p<0.05), however there was no significant difference between male and female VJ gain scores between pre-PAP VJ and 3, 4 and 5 minute post weighted exercise VJ. Conclusion: Results suggest that 30 seconds of weighted VJs causes fatigue which decreases VJ at 3 minutes post exercise. However, a PAP effect was seen at 4 and 5 minutes post weighted exercise significantly increasing VJ above pre testing. From a practical perspective, coaches must be aware of the complex nature of the fatigue-potentiation relationship when attempting to elicit a PAP effect in the individual athlete.