ABSTRACT

Purpose: The purpose of the study was to determine whether a dynamic warm up or static stretching had a greater impact on choice reaction time. Methods: Nine recreationally trained subjects (5 males, 4 females) performed single-step choice reaction time trials using the Makoto Arena II testing device, following either a dynamic warm up or static stretching protocol chosen at random for all participants. The static stretching (SS) and dynamic warm up (DWU) protocols the subjects performed lasted ten minutes in duration and were preceded with baseline testing of a sit and reach and a single-step choice reaction time trial. Results: Results of a dependent t-test (p < .05) on sit and reach indicated a significant difference for both baseline to SS (p = .007) and baseline to DWU (p = .000), but not when compared to each other, SS to DWU (p = .246). Dependent t-test results for choice reaction time showed significance(p < .05) for all three categories: baseline to SS (p = .023), baseline to DWU (p = .003) and SS to DWU (p = .009). However, it should be noted that although both SS and the DWU resulted in significance, the greatest difference in the speed for the choice reaction time was found with the baseline to DWU. Conclusion: DWU had a greater impact on a single step choice reaction time and thus should be considered as an element to be incorporated into any athletic training program to enhance athletic achievement.

INTRODUCTION

Prior to working out, training, or any physical activity, athletes typically will warm up the body in preparation for the activity to follow. Throughout the past couple of decades, warm up routines have evolved as more and more scrutiny has been leveled at training modalities in the pursuit of physical excellence.The possibility of improved performance is sought in supplements, training regimens, nutrition, and even the rest periods. Within the past couple of decades multiple studies addressed the effects standard stretching routines have on performance (2-4, 6, 8-10, 11, 13, 14). Because of the continuous quest for improvement through research, stretching and warming up are now effectively considered different modalities and are not just semantically different. Statics stretching (SS) is the more traditional form of preparation for physical activity while dynamic warm up (DWU) is a progressive buildup of the same physical movements required in the exercise the individual will be participating in. Past research has shown that DWUs will have more impact on power production, flexibility, and agility of the muscles while SS reduces explosive muscular output (2-4, 6, 8-10, 11, 13, 14). The research has overwhelmingly demonstrated in physical activity requiring short bursts of power and speed as opposed to long sustained muscle recruitment, a DWU should be utilized to improve athletic performance for multiple individual and team sports (1, 2, 4-6, 8, 9, 11-14). Although DWU has been demonstrated to improve speed and power, very little research has been done to show a DWU has the same effect with reaction time, and no research has utilized a single step choice reaction format. Our intent was to determine if the superiority of DWU versus SS in power production would also hold true for choice reaction time; thus making it much more applicable for sport training purposes. Multiple sport activities require the athlete to react quickly to a stimuli and the speed of the reaction can make a difference in being successful or failing. Therefore any method to enhance the ability to quickly assess and react to the stimuli should be addressed by the coaches in their efforts for attaining peak performance; thus presenting the need for research to study actual choice reaction and not just reaction from a force plate. Therefore with the convincing literature regarding DWU and SS, our hypothesis was that the DWU would produce a quicker choice reaction time as opposed to a traditional SS procedure. Due to the lack of literature in the area of actual choice reaction time it became apparent a pilot study needed to be conducted in order to develop an adequate methodology to allow for future research.

METHODS

Subjects

Subjects were recruited from the United States Sports Academy staff and students. The study included nine subjects, five males and four females, ages ranging from 24-56 years old. Each participant was recreationally active and gave informed consent. The subjects participated in a variety of sport backgrounds including basketball, volleyball, track and field, swimming, badminton, tennis, weightlifting and bowling. The study was approved by an Institutional Review Board for human subjects.

Study Design

Participants arrived and were given consent forms to review and sign. The Makoto Arena II was turned on and allowed time to heat up. Directions for all testing protocols were then explained in detail. Using the Sit & Reach box (Novel Products, Rockton Illinois) to measure flexibility, students were instructed to sit down on the floor with shoes off and put the base of their feet against the box. A researcher put a hand just above the subject’s knees to ensure the knees stayed flat. Subjects put one hand on top of the other one and extended over the box as far as they could reach. Measurements were taken at the tip of the middle finger when the subject was able to hold the stretch. Baseline sit and reach testing was completed in a non-stretched state and recorded in centimeters (cm). Subjects were allowed to do a practice trial and then performed an additional trial as their baseline. The subjects were then instructed to put shoes back on and move over to the Makoto Arena II for demonstration and explanation. The Makoto Arena II uses audio and/or visual cues to test choice reaction time. For the purposes of testing reaction time, a lateral single-step procedure that utilized two of the three towers was employed. Each subject stood behind a line that was exactly equal distance between the two towers and 1.2 m from the edge of the device. Subjects positioned their body in an athletic stance in preparation for movement. The subjects were then given the direction to take one step laterally and hit the target as quickly as possible with the same hand as the direction of the step. The target height was 122 cm from the floor (7). Each subject was given a few practice trials to ensure directions were adequately explained. Then scores were recorded until the participant had completed two tests stepping to their right and two tests stepping to their left to account for true athletic movement. The Makoto Arena II has built in software that both calculates the reaction speed and randomly selects the tower used for each trial; therefore each test had a fifty-fifty chance of being to the left or the right of the subject. Due to the randomness of the trials we settled on recording two scores stepping right and two stepping left for a minimum of 4 trials to ensure an accurate average of reaction time. By utilizing this procedure, no two subjects were alike and each subject had an equal number of trials recorded. Once baseline scores for both the sit and reach and the choice reaction tests were recorded, subjects randomly chose which set of stretches they would perform first by drawing sticks labeled with a D (dynamic) or S (static). Stretching protocols were explained for static and dynamic stretches. The duration for each protocol was 10 minutes. Static stretches were held for 12 seconds, and the same stretch was duplicated on the opposite limb being stretched. SS and DWU protocols are found in Tables 1 and 2. Time was kept using a stopwatch by one of the testers. Each stretch was independent and each subject determined their own levels of discomfort and stretch limitations. DWUs were performed downstairs in a fitness room, approximately 90 seconds from the human performance lab, therefore not impacting the effects of the DWU on the sit and reach or choice reaction tests. Following the SS or DWU protocols, the subjects returned and performed the sit & reach test. Measurements were taken following each testing procedure of SS and DWU and recorded on the subject’s data sheet. Once all subjects’ results were written down, researchers then repeated the same lateral one step choice reaction time testing protocol for each subject, following the second protocol of either SS or DWU, which was done on a separate day.

Statistical Analyses

Baselines for both the reaction time protocols and the sit and reach were analyzed against the two tests of SS and DWU. A timed measurement of the lateral single-step choice reaction time within the Makoto Arena II device was completed following a ten minute session of the SS or DWU protocol. The mean, mean difference, and standard deviation were then calculated for each variable. Dependent t-tests were used to compare the baseline reaction times to both reaction times following the SS protocol and the DWU protocol. An alpha level of p < 0.05 was used to establish significance. Sit and reach data analysis followed the same procedures mentioned above.

RESULTS

The mean and mean differences were calculations done manually by a calculator and the significance (p < .05) was found through the use of IBMSPSS Statistics 19 software. The means for sit and reach testing are as follows: baseline: 27.1 cm, SS: 30.4 cm, DWU: 32.0 cm. The mean differences were baseline to SS: -3.28cm, baseline to DWU: -4.89cm, and SS to DWU: -1.61 cm. Results indicated a significant difference for both baseline to SS (p = .007)and baseline to DWU (p = .000), but not when compared to each other, SS to DWU(p = .246). The mean for the baseline reaction time was .872 s, the mean following the SS protocol was .833 s and the mean following the DWU protocol was .796 s. The difference in the means for reaction time was baseline to SS:.039 s, baseline to DWU: .077 s, and SS to DWU: .038 s. Choice reaction testing for all three categories showed significance (p < .05): baseline to SS (p =.023), baseline to DWU (p = .003), and SS to DWU (p = .009). However, it should be noted that although both SS and the DWU resulted in significance, the greatest difference in the speed for the choice reaction time was found with the baseline to DWU. All results can be found in Tables 3 and 4.

DISCUSSION

At least one study has shown no effect on muscle force production (11), while the majority of studies have shown that a bout of SS produces an inhibitory effect on the contractile force production of a muscle (4,10,11,13). The studies reaching these conclusions were applied to outputs of power such as sprinting and agility drills. From these studies, we hypothesized that the same physiological responses affiliated with SS and DWU would produce similar results in a single-step choice reaction time. We hypothesized that a static stretch prior to a choice reaction timed test would not affect reaction time, whereas a DWU prior to testing would result in a quicker reaction time. Our hypothesis regarding the DWU was supported; however, the static stretching also produced a quicker time compared to the baseline choice reaction time. Results taken from the sit and reach test also showed a significant improvement for both SS and the DWU. From our findings, since both the SS and DWU produced an increase in flexibility from a non-stretched to post stretching protocol, the theory of stretched muscle fibers inhibiting muscle contraction force and thus reaction time is not fully supported. To account for both the SS and DWU producing a faster choice reaction time, there must be some other form of physiological adaptation occurring. It is possible that the concept of postactivation potentiation (PAP), which is defined by Behm and colleagues (2004) as an increase in the efficiency of the muscle to produce submaximal force after a voluntary contraction (4) is the rationale for both protocols producing positive effects. It is possible that the duration of the SS protocol was not long enough to inhibit the force-producing cross bridges that may develop with lower frequency stimulation but enough of a stimulation to actually form a greater number of these cross bridges, which would then result in an ability to create more force similar to the DWU (4). Because the DWU had a greater effect on increasing the choice reaction time than the SS we can infer that a DWU as opposed to a simple static stretch routine for a typical warm up for sports participation would be of a greater benefit. However, a short duration of SS coupled with a DWU certainly would not inhibit performance. Although the results support our hypothesis because this was a pilot study with a diverse and limited number of participants it cannot be generalized. Further research with a larger participant pool of males and females; trained and untrained athletes of varying sports would need to be tested under similar conditions to reach conclusive evidence.

CONCLUSION

The same physiological factors a DWU produces for speed, namely greater force of the muscle contraction, is also prominent with choice reaction time. In this small pilot study a one-step choice reaction utilizes the same physiology of muscle force production as a sprint; the effects of a DWU are similar, resulting in a quicker choice reaction time when compared to a standard static stretch protocol. Therefore those professionals responsible for preparing athletes in sports requiring quick reactions might want to consider incorporating a DWU as part of the athlete or teams’ development and preparation. Since this study was so limited in participants we suggest future research test entire athletic teams of males and females in sports dependent on reaction times. These teams should range in ages and skill level from interscholastic to the professional levels. With this larger pool of participants this hypothesis would be tested adequately allowing for the results to be more generalized, till then it is simply a pilot study with too few participants to conclusively generalize the results.

APPLICATION TO SPORT

Athletes at all levels are trying to develop and gain an edge in their performance, with sports that require a quick explosive movement, a few tenths of a second can mean the difference in getting to the ball first, blocking an attempt at a goal, digging a spike; the difference between success and failure. Personnel responsible for preparing athletes whether it is the coach, the strength coach, or a trainer must be cognizant of how to best prepare for training or competition. The warm up has become a critical component of preparation for athletes and teams dependent on quick, explosive, and reactive movements. Unlike a static stretching protocol, DWU’s has been shown to enhance and better prepare athletes for performance by not stretching the muscles past the point where they can quickly recoil and exert their maximal force. The DWU incorporates an increase in body temperature as well as functional stretching of the muscles. This state of higher body temperature and a slightly stretched muscle has demonstrated better speed and agility times. Therefore, athletes and coaches responsible for their preparation should be utilizing a DWU as a part of their daily training protocol for better athletic performance.

REFERENCES

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TABLES AND FIGURES

Table 1

Table 2

Table 3

Table 4