Acute Effect of Countermovement Jumping on Throwing Performance in Track and Field Athletes During Competition

Abstract

Karampatsos, GP, Korfiatis, PG, Zaras, ND, Georgiadis, GV, and Terzis, GD. Acute effect of countermovement jumping on throwing performance in track and field athletes during competition. J Strength Cond Res 32(1): 359–364, 2017—The purpose of the study was to investigate whether performing 3 consecutive countermovement jumps (CMJs) just before an attempt enhances performance in track and field throwers during competition. Twelve shot putters, 8 hammer throwers, 9 discus throwers, and 3 javelin throwers of both sexes participated in the study. They performed 3 maximal CMJs 85 ± 12 seconds before the second, fourth, and sixth attempt during 3 different official competitions of national level. Maximal strength (1 repetition maximum [1RM]) in squat and bench press was measured 1 week after the competition. Mean throwing performance was significantly higher after the CMJs intervention (2.66 ± 4.3%, range of increase 0.02–18.98%, p = 0.0001). Similarly, maximum throwing performance was significantly higher after the CMJs (2.76 ± 3.29%, range of increase 0.09–13.93%, p = 0.0009). All but 2 athletes increased their best performance after the CMJs. The percentage increase in performance was similar between sexes (male athletes 2.56 ± 3.01%; female athletes 3.06 ± 3.76%, p = 0.677), but it was higher for the “lighter throws” (discus and javelin throw: 4.66 ± 4.11%) compared with the “heavier throws” (shot and hammer throw: 1.62 ± 2.04%, p = 0.008). The percentage increase in performance was not significantly correlated with 1RM squat or bench press, anthropometric characteristics, and personal best performance. These results suggest that performing 3 CMJs approximately 1 minute before an attempt may increase track and field throwing performance during competition.

Introduction

Track and field throwers occasionally use various muscular actions and/or exercises just before a competitive attempt to enhance their performance. This practice is most likely based on the phenomenon of postactivation potentiation where a preconditioning action may acutely increase subsequent muscular performance (²²), and it has been documented both in human and in animal muscles (^9,15). The principal mechanisms underlying postactivation potentiation are considered to be the phosphorylation of myosin light chains in the sarcomeres, increased recruitment of higher threshold motor units, and possible change of the fascicle angle of the recruited muscles (²²). In the laboratory setting, a single maximum isometric voluntary contraction of 10 seconds duration may increase the twitch response during the following minutes (¹⁰). Similarly, field studies revealed that explosive exercises, such as the snatch, enhance subsequent jumping performance (¹⁶).

However, postactivation potentiation is a short-lived phenomenon (²²). Thus, the conditioning actions should be performed just before an attempt when equipment availability is limited. Accordingly, simple powerful muscular actions have been used to potentiate throwing performance. For example, throwing an implement of 1.37 kg or 2.27 kg heavier than the competition implement enhanced peak weight throw performance in young weight throwers during training (¹²). Recently, it was found that performing either 3 consecutive countermovement jumps (CMJs) or 20 m sprinting just before shot putting provokes an increase in performance in shot put athletes of various calibers by 2.6%, during training (¹⁹). Interestingly, all the athletes participated in that study benefited from these potentiating activities (¹⁹). However, during the actual competition many parameters may affect performance such as the level of the opponents, the invalid attempts of the athlete and those of the opponents, the psychological stress, etc. Thus, the usefulness of such intervention (e.g., CMJs or sprinting) should be tested during competition to be proved as a valid means of acute increase in throwing performance.

Countermovement jumping is commonly executed during training, it has limited skill and equipment requirements, and it can be readily performed during an official track and field event, thus it could be a good candidate as a conditioning intervention. However, the use of countermovement jumping as a potentiating stimulus just before a throwing attempt during real competition has not yet been tested. Aim of this study was to investigate whether performing 3 consecutive maximal CMJs just before an attempt enhances performance in track and field throwers during competition.

Methods

Experimental Approach to the Problem

This study addressed the question whether track and field throwing performance would be altered during competition after performing 3 consecutive CMJs before an attempt. Three maximal consecutive countermovement jumps were used as the potentiating stimulus 1 minute before performing the second, fourth, and sixth attempt. Performance in these attempts was compared with performance in the first, third, and fifth attempts where no preconditioning stimuli were implemented. Analysis of the previous years' results of the national throwing events revealed that there was no statistically significant difference in throwing performance between the 6 attempts for the top 8 athletes, both in male and female throwing competitions during shot put (p = 0.806, η² = 0.071), discus throw (p = 0.988, η² = 0.005), javelin throw (p = 0.990, η² = 0.001), and hammer throw (p = 0.877, η² = 0.059). Thus, we decided to use the potentiating stimulus in half of the attempts every other attempt starting with the second. Each athlete performed the 3 CMJs immediately after the call to perform the next attempt. This was 85 ± 12 seconds before the start of the attempt: one of the researchers was recording the time between performing the CMJs and the subsequent attempt.

Athletes sometimes choose their own preconditioning methods before an attempt, therefore it was challenging to convince the participants to perform this specific preconditioning method consisting of 3 CMJs. For this reason, a pilot set of experiments were executed with just 1 set of 3 CMJs performed 1 minute before the fourth attempt in a single national competition in 8 well-trained shot putters. The results revealed a significantly higher performance (1.66 ± 2.09%, p ≤ 0.05) in the fourth attempt compared with the other attempts. With these results, we convinced a number of coaches to allow their athletes to participate. Data presented in this study were collected from the official results of 3 track and field competitive events of national level between May and July. All throwing events were performed between 16:00 and 20:00 hours.

Athletes of various calibers and of both sexes were included because previous results showed that shot putters increased their performance with 3 CMJs regardless of their performance level and muscular strength (¹⁹). Strength tests were performed to investigate the possible relationship between the acute change in performance after the 3 CMJs and muscular strength of the athletes. This notion was based on previous studies (^3,20).

Subjects

Thirty-two male and female track and field athletes of various calibers with a 8 ± 2 years training and competition experience signed a consent form to participate in the study after being thoroughly informed about the experimental procedures. One of the shot putters was under 18 years of age, thus parental consent was also obtained. Their detailed characteristics are presented in Table 1. All athletes were in good health and were receiving no medication. All procedures were approved by the Ethics Committee of the S.P.E.S.S. of the local university.

Table 1.: Characteristics of the track and field throwers of the study.

Procedures

Countermovement Jumps During Competition

Before entering the competition, each athlete performed freely his/her individualized 30–40 minutes warm-up (jogging, stretching, and submaximal throwing attempts). Athletes then entered the competition with their first attempt without performing any preconditioning actions. This was also repeated for the third and fifth attempts. In contrast, they performed 3 successive CMJs, approximately 1 minute before the second, fourth, and sixth attempts. All athletes were familiar with countermovement jumping through their training. They were instructed to start each jump from the standing position, bend their thighs as fast as possible until they were in parallel to the ground, and then jump as high as possible with free arm swinging. No rest was allowed after each jump. After the third jump, athletes walked slowly to the throwing circle or to the javelin lane and performed the throw. The time interval between the first and second attempt was 11.2 ± 3.2 minutes, between the second and third attempt it was 10.0 ± 3.1 minutes, between the third and fourth attempt it was 10.3 ± 4.1 minutes, between the fourth and fifth attempt it was 8 ± 2.8 minutes, and between the fifth and sixth attempt it was 7 ± 2.5 minutes.

1 Repetition Maximum Strength

Assessment of 1 repetition maximum (1RM) in squat and bench press was performed 6–9 days after the competition. Squat was performed on a weightlifting plateau for all athletes using an Olympic bar. Hammer throwers did not perform the bench press 1RM test because this exercise is not regularly performed by these athletes during training. All athletes were familiar with both exercises because they used them regularly during training over the years. After a short warm-up on a static bicycle and a few stretching exercises, athletes began the testing session with the squat and then with the bench press with a rest period of 30 minutes between exercises, according to previously described methods (¹). Athletes performed incremental submaximal efforts until they were unable to lift a heavier weight. At all times, 2 researchers were present to evaluate the technique of the lifts and vocally encourage the athletes. A 3-minute rest was allowed between sets. The Intraclass Correlations Coefficient (ICC) for 1RM strength in squat (ICC = 0.96, N = 13, 95% CI: Lower = 0.81, Upper = 0.94) and bench press (ICC = 0.92, N = 13, 95% CI: Lower = 0.91, Upper = 0.97) in a similar group of athletes was previously determined.

Statistical Analyses

All data are representing as mean ± SD. For the determination of the sample size, an a priory power analysis (G*Power ver 3.1, Frank Faul; Universitat Kiel, Kiel, Germany, (⁶)) revealed a significant high power of sample size (F = 4.1708, p = 0.945). Analysis of variance for repeated measures was used to investigate changes in shot put, hammer, discus, and javelin throwing performance before and after CMJs. Separated 1-way analysis of variance (ANOVA) were used to investigate changes between the percentage changes in throwing performance according to sex, the throwing event, and the mass of the throwing implements. Pearson's (r) product moment correlation coefficient was used to explore the relationships between different variables. Within-subject variation and reliability were determined for all variables by calculating the confidence limits (95% CI) and ICC coefficient as described before (¹¹). Significance p ≤ 0.05 was used as a 2-tail level of significance.

Results

The best throwing performance and 1RM strength for male and female athletes are presented in Table 2. Mean throwing performance was significantly higher after the CMJs intervention compared with the attempts with no preconditioning (2.66 ± 4.3%, range of increase 0.02–18.98%, p = 0.0001, η² = 0.392). Similarly, maximum throwing performance was significantly higher after the CMJs (2.76 ± 3.29%, range of increase 0.09–13.93%, p = 0.0009, η² = 0.301). All but 2 athletes increased their best performance after the CMJs. Specifically, shot put performance was significantly increased after the CMJs (best performance without jumps: 12.06 ± 2.20 m; best performance after CMJs: 12.27 ± 2.16 m, p = 0.027, η² = 0.372, n = 13). Similarly, the hammer throwing performance was significantly increased after the CMJs (best performance without jumps: 54.76 ± 14.11 m; best performance after CMJs: 55.37 ± 14.07 m, p = 0.027, η² = 0.525, n = 8). Discus throwing performance was significantly increased after CMJs (best performance without jumps: 38.01 ± 8.00 m; best performance after CMJs: 39.30 ± 7.94 m, p = 0.009, η² = 0.595, n = 9). Finally, javelin throwing performance was also increased after CMJs (best performance without jumps 35.36 ± 2.99 m; best performance after CMJs: 38.00 ± 1.48 m, n = 3).

Table 2.: Squat and bench press 1 repetition maximum strength and peak throwing performance during the competition of the track and field throwers of the study.*†

Figure 1 Collapsed 1-way ANOVA revealed that the percentage change in performance was similar between sexes (male athletes 2.56 ± 3.01% vs. female athletes 3.06 ± 3.76%, p = 0.678, η² = 0.005, ns) and between shot put and hammer throw (1.90 ± 2.45%, vs. 1.20 ± 1.24%, respectively, p = 0.472, η² = 0.029, ns). Track and field throwing events are often categorized as heavy (shot put and hammer throw) and light (discus and javelin throw) based on the implement mass. When this informal classification of the throwing events was considered, it was found that the performance changes after the CMJ potentiation was higher for the “lighter throws” (discus and javelin throw: 4.66 ± 4.11%) compared with the “heavier throws” (shot and hammer throw: 1.62 ± 2.04%, p = 0.009, η² = 0.208). There was no significant correlation between the percentage change in performance after the CMJs intervention and athletes' 1RM strength, anthropometric characteristics, and personal best performance (Table 3).

Figure 1.: Maximum (best) throwing performance without preceding jumps and after 3 countermovement jumps in 29 track and field throwers during competition (* = p ≤ 0.05, after vs. before the countermovement jumps). All valid attempts were considered.

Table 3.: Correlation coefficients (Pearson r) between the percentage increase of maximum throwing performance after the countermovement jumping intervention and anthropometric characteristics, 1 repetition maximum strength, and individual best performance.*†‡

Discussion

Figure 2 The main finding of this study was that throwing performance was significantly increased immediately after performing 3 successive maximal CMJs in track and field throwers of moderate performance level during competition. This result might be attributed to the phenomenon of postactivation potentiation where peak force and the rate of force development are enhanced immediately after employment of a conditioning contraction (²²). Previous field studies have shown that intense muscular actions induce an increase in subsequent powerful performance. For example, peak weight throw performance can be enhanced after throwing a heavier implement in young weight throwers (¹²), whereas a powerful muscular action, such as the snatch, can lead to an acute increase in jumping performance (¹⁶). Moreover, performing 5 consecutive drop jumps from 40 cm induces a significant acute increase in throwing performance in moderately trained subjects (²¹). Similarly, the present results reveal that powerful muscular actions, such as the countermovement jumps, may enhance throwing performance during competition in experienced track and field throwers of various performance level. Interestingly, both the best and the average throwing performance were significantly enhanced after jumping. This result underscores the effectiveness of these interventions in enhancing throwing performance during competition.

Figure 2.: Mean throwing performance without preceding jumps and after 3 countermovement jumps in 29 track and field throwers during competition (* = p ≤ 0.05, after vs. before the countermovement jumps). All valid attempts were considered.

Interestingly, throwing performance was increased immediately after CMJs in all but 2 of the throwers. The lack of increased performance in these 2 throwers is unclear and may be attributed to nonbiological factors such as the psychological pressure during the real conditions of competition. Previously, the acute throwing performance increase after 5 maximal drop jumps was evident only in those individuals with the highest percentage of type II muscle fibers in their vastus lateralis (²⁰). The possible beneficiary effect of a higher percentage of type II muscle fibers in PAP has been described before (¹⁰). This has been related to a higher level of acute phosphorylation of myosin light chains in type II fibers after the conditioning intervention, which is thought to increase the sensitivity of actin-myosin to Ca²⁺ during the following muscular action (^8,9,17,18). It has been hypothesized that a fast and powerful muscular movement might activate strongly the type II muscle fibers, thus enhancing the phosphorylation of myosin light chains in these fibers, and subsequently increases the throwing performance in subjects possessing a higher percentage of type II muscle fibers. Track and field throwers have, in general, a relatively higher percentage of type II fibers in their lower-body muscles (^4,5). In view of that, it might be speculated that experienced throwers can be benefitted by an intense muscular action just before their main performance presumably because they possess a relative high percentage of type II muscle fibers in the protagonist muscles. However, the fiber type composition of the protagonist muscles of the current participants was unknown.

It has been previously suggested that muscular strength might positively affect the phenomenon of postactivation potentiation (^7,13), although other reports failed to show such a relationship (^19,20). In this study, 1RM strength in squat and bench press was not significantly correlated with performance enhancement after CMJs. It seems that other biological or even psychological parameters might be more important for the postactivation potentiation during powerful action in competition. Similarly, the increase in throwing performance after the CMJs was not correlated significantly with individual throwing performance as also shown previously (¹⁹). Again, it seems that other parameters (e.g., % of type II muscle fibers) might be engaged in this phenomenon. From a practical point of view, it seems very promising that almost all track and field throwers regardless of the throwing event they compete, their training experience, muscle strength, performance level, and sex, might be benefited with such intervention. Interestingly, the increase in performance was higher for the discus and javelin throws. These 2 implements have lower mass (1–2 kg, and 0.6–0.8 kg, respectively) and they allow for a faster delivery time (^2,14), and it might be speculated that beneficiary effect is linked with the activation of type II muscle fibers as described in the previous paragraph. Engagement of a larger number of javelin throwers would have provided a better insight into performance enhancement in this group of athletes but this was not feasible at the moment. Another limitation of the study was the performance level of the athletes. It may be speculated that the current results do not apply in elite track and field athletes. Although previous reports revealed similar result in well-trained throwers during training (¹⁹), this remains to be explored during competition.

In conclusion, the results of this study indicate that 3 consecutive countermovement jumps performed approximately 1 minute before the attempt during competition induce an acute increase in throwing performance in experienced track and field throwers of various caliber. This effect is not influenced by the individual muscular strength or performance level. However, the acute increase in performance seems to be higher for the discus and javelin throws compared with the shot put and hammer throw.

Practical Applications

The present data suggest that track and field throwers may acutely increase their throwing performance during an official competition by approximately 2.7% if they perform 3 consecutive CMJs approximately 1 minute before the throwing attempt. Discus and javelin throwers may benefit more (approximately 4.7%) than hammer throwers and shot putters. Countermovement jumps are easy task to perform without the need for complex equipment. This acute increase in performance seems to be independent of the training experience and muscular strength. Both male and female throwers may be aided to the same degree. Although the current results suggest that performing 3 CMJs approximately 1 minute before a throwing attempt during competition may increase performance, other time frames between CMJs and a throw may also enhance performance (e.g., 3–5 minutes). Future research should investigate this aspect.