Determining the Anaerobic Power Output Differences between the Genders in Untrained Adults

Introduction Anaerobic power is power used in high-intensity bouts of exercise lasting fewer than ten seconds; which is the peak amount of time for phosphocreatine reserves to empty as a primary fuel source. It is expressed in terms of watts of force per kilogram of bodyweight. Power is considered a crucial component in overall athleticism. Ample power tends to be a key difference maker in short-terms bouts of fast twitch, Type I myo-fiber, events. For example, athletic events, or competitions which call for optimal power output, are weight lifting, sprinting, jumping and wrestling, although may other team sports and individual sports and competitions also have high anaerobic power output demands. Anaerobic power can be measured and improved. The three physical assessments in this study are commonly used to measure power. Each has been researched and normative and standards have been established for force production by their use. They are the Vertec vertical jump, Force plate and Wingate tests (WAnT). Also, several formulas are used to calculate power output from the vertical displacement from the Vertec. These formulas are named for the scientists who developed them. They are the Lewis, Sayer, Harman and Johnson formulas. In the same way there exists a most accurate way to measure someone’s running speed, certain power output measuring tests have proven to be superior to the others. The force Plate is currently the “gold standard” for measuring anaerobic power output. Because having a higher threshold for anaerobic power output is a clear advantage to most sports and skills it is important to determine power output to know if a competitive disadvantage exists. Most people might assume because males are generally physically stronger and carry more muscle than females per kilogram of bodyweight, males must produce more power. But because we understand anaerobic power is a ratio of watts of force to kilograms of bodyweight, this assumption may not be the actual case. It is expected for there to be no significant difference of anaerobic power output between the male and female subjects based on power/mass ratios in the three anaerobic power output assessments. Purpose The purpose of this study was to determine if a difference of anaerobic power output between the genders existed while determining the most reliable power-measuring exams and formulas. Methods Ten non-athlete males (age 27.1 yrs., height 181.67 cm, weight 89.82 kg) and eight non-athlete women (age 24.13 yrs., height 167.95 cm, weight 74.97 kg) of the University of Texas at Arlington volunteered to participate in this study. Each subject contributed data in the three anaerobic power output assessments. Subjects were randomly divided and assigned to a particular starting exercise assessment at random order. Each subject preformed a power output test using Force Plate technology, which displays the power measurements on-screen without the need for hand-written calculations. In the force plate test, subjects stood still on the measurement pad so weight could be recorded and calibration accomplished. Then, the subject jumped as vertically high as they could from the plate and landing back on the plate; then the power output was calculated. Subjects also performed a vertical jump test with equipment designed by Vertec. In this test subjects measure their standing reach in inches, then subtract that amount from three trails of a standing maximal vertical jump. The results of the Vertec were used in each formula designed to measure anaerobic power. For the results of the Vertec subjects performed their own power calculations using said formulas. The formulas are the Lewis, Sayer, Harman and Johnson formulas. Subjects also performed a Wingate Test, which also displays the anaerobic power output as well as fatigue rate. © Center for Promoting Ideas, USA www.aijcrnet.com 65 While fatigue rate is not a direct reflection of anaerobic power production, it does provide limited insight to the storage reserves of phosphocreatine the subject posses. During the Wingate test subjects peddle as fast as they can for one full minute after a warm-up of pedaling at 80 rotations per minute for one minute. At the conclusion of each test subjects were given ample time to recover before beginning the next test. Results The anaerobic power output difference between the genders was significant based on the results of most tests but not every test. The null hypothesis stated that there would be no difference in anaerobic power output between the genders. In the Force Plate test the distribution of the countermovement among males to females (A: 42.3, 24.88 ±: 9.05, 7.64) rejects the null hypothesis (p = 0.003). The distribution of Peak Power among males to females (A: 5365.3, 3123.85±1088.459, 884.685) rejects the null (P= 0.001). The distribution of Peak Power/W/kg among males to females (A: 58.31, 39.70 ± 9.353, 12.249) rejects the null hypothesis (P=0.009).Within the findings from the Vertec vertical jump test we find only significant differences. We reject the null hypothesis across the board in the displacement category (P= 0.006), Lewis Power (P= 0.011), Sayer Power (P= 0.002), Harman Peak and average power respectively (P= 0.001, 0.000), and Johnson Peak power and average power respectively (P= 0.002, 0.027).Our Wingate test findings rejected the null hypothesis in the categories of average power (P= 0.000), peak power (P= 0.000), average power/kg (P= 0.000), peak power/kg (P=V0.027). Conclusion Significant power output differences do exist in the tested sample population. This conclusion was based on the results of Wingate testing and comparative means in the Force Plate test. It was found that there were significant gender differences in peak power and mean power revealing that other factors in addition to body dimensions account for the gender differences in anaerobic power. The results of the study indicate that the relationships of their findings showed that when individuals with different body sizes are compared, individuals with small body size are at a disadvantage when compared with absolute anaerobic power parameters, on the other hand, large body sized individuals are at a disadvantage when compared with respect to ratio scaled parameters. Therefore, analysis should be considered as a method to account for the influence of body size in intergroup and gender comparisons of anaerobic performance (Hazir & Kosar, 2007). This is not out of line with what we predicted in our introduction. Other studies used in research suggest a similar result. In terms of the highly affective Wingate test, when using the lighter resistance (0.080 kg/kgbw), power production for males was greater than almost all previously reported findings by approximately 10 to 30%. When using the heavier resistance (0.095 kg/kgbw), the increase in power production in males was even greater (Richmond et al., 2011). This result suggests that no method adequately adjusts for the gender differences and thus the best methods for studying physical performance of males and females would be separately (Hazir & Kosar, 2007). Background Anaerobic power is power used in high-intensity exercise activities lasting fewer than ten seconds. There is a difference in anaerobic muscular power and muscular endurance. This differentiates the skills required to excel in a sport like football, where action bouts require maximal physical exertion for brief moments followed by short rest periods, rather than soccer, where the majority of the competition requires moderate levels of exertion for a longer period of time from its participants. Power is expressed in terms of watts of force per kilogram of bodyweight. As stated before, power is considered a crucial component of overall athleticism. Ample power tends to be a key difference maker in short terms bouts of fast twitch events. For example: weight lifting, sprinting, jumping and wrestling. Anaerobic power can be measured by way of several assessments developed over the years from research-based exercise physiologist and sports trainers. Anaerobic power can be improved through exercise and training specified to increase power output. When considering an athlete’s performance in a power output measuring exercise, it is important to consider the other factors working in the athletes favor simultaneously. Aerobic fitness of high-performance explains about 40% of the variance in performance of power output results. This suggests that other factors than anaerobic power such as technical abilities need to be considered in the physiological assessment of these athletes, even in anaerobic power assessments such as the Wingate Test or Force Plate (Vaitkevičiūtė & Milašius, 2012). Because having a higher threshold for anaerobic power is a clear advantage to most sports and skills it is important to determine power output. American International Journal of Contemporary Research Vol. 4 No. 4; April 2014 66 With the introduction of Title 9 there has been increased involvement of female participants in high-intensity exercise and sport. As a result, more questions are being asked about the athletic capabilities and physical strength output female sport participants possess. From there, some findings have sparked important research questions about male and female differences in exercise performance (Clare & Webber, 2006). These questions about gender differences are relevant due to the establishment of training protocols and exercise prescription, and in the field of sport-related physical therapy treatment female participants may receive. Much past research has typically sought to answer questions based on muscular production differences and determine physiological differences based on anatomy and biomechanical factors among the genders. Most people might assume because males are generally physically stronger than females, males must produce more power. This study is laid out to determine if gender difference do exist, solely in terms of anaerobic power output. It is also a goal of this study to determine the most reliable power-measuring exercise tests and power measuring formulas. Of the three power assessments used in this research the Wingate is among the most studied. In a previous study, which also used the Wingate, it was found the difference between the sexes in peak leg power was as high as 33% (Van Praagh, 1990). But because we understand anaerobic power is a ratio of watts of force to kilograms of bodyweight this may not be the case once all other factors are considered. When refereing to Figure 1 the size difference in the subjects used in this study is clearly apparent. In maximal anaerobic tests, like the WAnT, ratio scaling for lean body mass creates a disadvantage for individuals who have large body size compared to small body sized individuals, as during these types of activities only limited muscle mass is active. The above-mentioned problems have also been experienced in gender comparisons (Hazir&Kosar, 2007). It is expected for there to be no significant difference of anaerobic power output between the male and female subjects. However, ample data show that male participants generate significantly greater lower limb muscle power than female participants (Clare & Webber, 2006). This data is contradictory to previous findings. Previous studies have sought out to find the results to the same question. Findings are controversial when data are expressed relative to body weight, lean body mass, muscle cross sectional area or active muscle mass. Some studies reported that gender differences in anaerobic performance were eliminated after normalization of thedata for anthropometric measures while others did not (Hazir & Kosar, 2007). In yet another previous study to measure gender related differences of anaerobic power output in subjects with chronic obstructive pulmonary disease it was determined fat-free mass in the legs of subjects was 27% lower in women than in men (Yquel & Tessonneau, 2006). Fat-free mass does not have to specify muscle; bone is also involved, but we well know the ratio of fat-free mass to fat in the lower body should be a reliable indicator of Type I and II muscle fiber activation, hence: power. Figure 1: Size Differences Between The Genders