Acute Effects Of The Power Snatch On Vertical Jump Performance.

NICK DIAZUNIVERSITY OF THE PACIFICHEALTH EXERCISE & SPORT SCIENCES DEPARTMENT

A Thesis Submitted to the Faculty of the Office of Research and Graduate Studies In Partial Fulfillment of the Requirements for the Degree of MASTER OF ARTS.

TABLE OF CONTENTS

• Introduction

• Review of the Literature

• Methodology

• Results

• Discussion

Introduction

INTRODUCTIONSTRENGTH & CONDITIONING Maximize athletic performance. Increase strength, speed, power. Improve athleticism. Injury prevention. Improve motor patterns. Hypertrophy. Aerobic endurance. Free weights, machines, body

weight.

OLYMPIC WEIGHTLIFTING Olympic sport Ability to perform the Snatch. Ability to perform the Clean &

Jerk. Maximize power output. Increases ROM. Increase kinesthetic awareness. Technical proficiency.

INTRODUCTION

INTRODUCTION

Olympic weightlifting has a strong relation with athleticism and sports performance.

Several studies have found increases with power production and sports performance using Olympic style weightlifting. (Naruhiro et,al. 2008) (William et,al. 2012)

The power produced from these movements have a direct effect on the lower extremities, which may transition into an athlete’s performance.

INTRODUCTION

Why use the power snatch?

There is a limited amount of research on the snatch movement itself and its effects on performance. (Ho, Lorenzen, Wilson, Saunders, and Williams 2014)

These movements have similar mechanics to jumping movements such as countermovement and vertical jumps. (Waller et al, 2007)

PURPOSE

RESEARCH QUESTIONThe purpose of this study was to examine the acute effects of the power snatch exercise at specific intensities on vertical jump performance.

HYPOTHESISIt was hypothesized that vertical jump performance would increase using an ascending power snatch protocol.

Review of Literature

Olympic Weightlifting And Its Relation To Sports

Hori et al (2005) describes the importance of power in sport, and how well weightlifting is in enhancing variables such as strength and power. Weightlifting exercises are now used in strength and conditioning programs because of their usefulness in developing power and strength.

Further insight is provided by Hori, Newton, Nosaka, & Stone, (2005). This study explores the biomechanical and physiological principals of Olympic style weightlifting. This study reinforces the application of weightlifting in an athlete’s performance, particularly high-load speed strength activities.

Effects Of Olympic Weightlifting On Sports

Performance Scherfenberg & Burns (2013) implemented hang cleans in high school weight training classes. This study compared a squat group (SQG), hang clean group (HCG), and a mixed group which consisted of both hang cleans and squats (CSG). Vertical jump performances were taken before and after these programs were implemented. Significant differences were found in vertical jump performance for both hang clean (HCG) and the mixed group (CSG).

Effects Of Olympic Weightlifting On Sports

Performance Tricoli et al (2005) performed a similar study on power development using a weightlifting group and a vertical jump group. Each group was assigned to a training program consisting of weightlifting or vertical jump exercises, with a control group being used as well. The weightlifting program consisted of high pulls, power cleans, and clean & jerk movements. Measurements were taken in the squat jump, countermovement jump, 10 and 30-m sprint speeds, an agility test and a 1RM half squat. Both groups increased their vertical and countermovement performances. The weightlifting group however increased their vertical jump more than the vertical jump group. No significant changes were found in the control group.

Effects Of Olympic Weightlifting On Sports

Performance A study by Kawamori et al (2005) had fifteen participants perform hang power cleans using a force plate. Intensities ranged from 30-90% of their 1RM with the peak power output at 70%. Utilizing proper intensities for peak power output may be used in weightlifting programs to gain the greatest increases in performance.

Ascending Protocol Using The Squat Exercise

Hirayama (2014) investigated the acute effects of an ascending intensity squat protocol on vertical jump performance. Single repetitions of the squat were used at 20, 40, 60, and 80% of the participants 1RM. This study consisted of 14 college weightlifters participating in two sessions. One session was a control group, while the other included an ascending squat protocol. Vertical jump performance was measured after each squat movement. Hirayama included a 1 minute rest interval in between the squat and jumping protocols. Similar studies with similar protocols did not have a rest interval in between, allowing effects of fatigue to set in. Performance gradually increased after the 60% and 80% 1RM, making the squat a useful tool for athletes who require high muscular power for jumping activities. The protocol and methodology from this study were mirrored for this research, replacing the squat movement with a power snatch movement.

Purpose For Investigating The Power Snatch

Waller et al, (2007) provides an overview on the application of the power snatch for athletic conditioning. Waller reveals several techniques when introducing these lifts into strength and conditioning programs. Utilizing the power version of these lifts helps eliminate error in technique, and simplifies the movement. The power snatch is used with lighter weight than a traditional snatch, but requires a high amount of bar velocity. These movements have similar mechanics to jumping movements such as countermovement and vertical jumps. The power produced from Olympic style exercises have a direct effect on the lower extremities, which may transition into an athlete’s performance.

Post Activation Potentiation

Acute vs. Long term adaptations. This study will focus on acute effects that may be found from a post activation potentiation (PAP) effect of type II muscle fibers. (Hodgson, Docherty, Robbins, 2005)

Contractile history caused by stimuli may have an effect on subsequent performance (Hodgson, Docherty, Robbins). In this case the power snatch was used before a vertical jump test.

Post Activation Potentiation

Post activation potentiation.

Response given by a muscle to an induced stimuli (volitional/chemical).

Balance of processes that cause fatigue and potentiation.

Dependent on intensity and duration (Hodgson, Docherty, Robbins, 2005).

Methods

Subjects

10 participants 8 Males, 2 Females 18 to 35 years old Volunteer basis Previous experience with

Olympic weightlifting. Six month data collection period. Two sessions with at least 48

hours in between. Participants ranged from novice

to intermediate levels.

Protocol

Vertical jump measurements were recorded using a Vertec. Each participant was tasked with establishing a 1RM in the power

snatch exercise. Two sessions were agreed upon to perform the measurements in

vertical jump performance. This study employed a 1-group experimental design with a PS

and CON group occurring in a random order.

Protocol

A baseline vertical jump measurement was taken prior to the session in both conditions.

Protocol

The participants performed a dynamic warm up after their baseline, followed by a movement prep warm up for the vertical jump during the CON session. The same dynamic warm up was administered during the PS session, along with a barbell complex used as a primer for the power snatch exercise.

After the participants completed the dynamic warm up, a three minute interval was given between attempts to allow for recovery. Subjects in the PS session performed the power snatch with increasing loads.

Protocol

1 repetition of the power snatch was performed at 20% 1RM, 40% 1RM, 60% 1RM, and 80% 1RM.

After the power snatch was performed at the prescribed weight, a 1 minute recovery period was given, totaling a 3minute interval.

Protocol

Following the rest period the subject was asked to attempt 2 vertical jumps, followed by their 3 minute rest period.

This was repeated in an ascending order (40%, 60%, and 80%).

Subjects in the CON group were placed in a seated position during the rest intervals and did not perform the power snatch.

Data collection sheet.

Click icon to add picture

Results

Statistical Analysis

A student’s paired t-test was used to compare differences in the baseline jumps from the PS and CON group.

No significance was found in this trial, requiring additional analyses of condition and trials. A univariate analysis of variance (ANOVA) was used to determine changes in jump height in the PS and CON conditions among all trials.

Level of significance was set at p ≤ 0.05.

An effects size was taken from both groups and used in a power analysis.

10 participants were recorded for this study.

Each participant attended two sessions, each having a total of 4 trials including a baseline (2 conditions x 8 trials).

Table 1. Paired t-test Table 2. Two way ANOVA

Figure 1- Average Jump Height In PS And CON Trials

Power Analysis

When no significant differences were found, a power analysis was performed in order to establish a proper sample size.

An effects size of 0.466 was found showing a sample size of 58 participants were needed to find a significant difference in vertical jump height while using the same protocol.

Discussion

Discussion

This study was designed to find the acute effects of the power snatch exercise on vertical jump performance.

The main findings of this study showed little to no significance between groups, however a greater difference was found in the last trial between both groups as performance decreased in the CON group.

These findings did not support the hypothesis that the power snatch exercise would show a significant difference in vertical jump performance.

During the baseline trial (Table 1) no difference was observed. This supports the fact that both testing session were performed under equivalent conditions.

(a) the power snatch exercise is a more technical exercise when compared to the squat exercise.

(b) experience levels amongst participants varied from beginner to more advanced.

(c) target population was Olympic weightlifters, however when participants were hard to find a second approach was to teach the movements to those who have had any amount of experience with general weight lifting exercises.

The following factors may explain why differences in results were found:

Conclusion

This research was performed to show the viability of the power snatch exercise in vertical jump performance.

Individual differences such as training history and experience with Olympic weightlifting may have affected jump performance.

Although no significance was found, further research using the same protocol with a larger population may find more significant information.

References

Ho, L., Lorenzen, C., Wilson, C., Saunders, J., & Williams, M. (2014). Reviewing current knowledge in snatch performance and technique: The need for future directions in applied research. Journal of Strength and Conditioning Research, 28(2), 574-586.

Hori, N., Newton, R., Andrews, W., Kawamori, N., McGuigan, M., & Nosaka, K. (2008). Does performance of hang power clean differentiate performance of jumping, sprinting and changing of direction? Journal of Strength and Conditioning Research, 22(2), 412-418.

Hori, N., Newton, R., Nosaka, K., & Stone, M. H. (2005). Weightlifting exercises enhance athletic performance that requires high-load speed strength. Strength and Conditioning Journal, 27(4), 50-55.

Stone, M., Pierce, K., Sands, W., & Stone, M. (2006). Weightlifting: A brief overview. Strength and Conditioning Journal, 28(1), 50-66.

Gratton, C & Jones, I. (2010). Research Methods for Sports Studies 2nd Ed. London, Routledge. Atkinson, M. (2012). Key Concepts in Sport & Exercise Research Methods. London, Sage. “International Weightlifting Federation." International Weightlifting Federation. N.p., n.d. Web. 08 Dec.

2014. Duba, James, William J. Kraemer, and Gerard Martin. "A 6-Step Progression Model for Teaching the Hang Power Clean." Strength and Conditioning Journal 29.5 (2007): 26-35. Web.

References

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