Two levels of anaerobic power are relevant to an athlete's performance. Peak power is the amount of power the athlete can consciously produce very quickly within two seconds. And this reflects both the athlete's ability to use the ATP store and the maturation of the nervous system. Mean anaerobic power is the highest power output an athlete can consciously maintain for 10 to 30 seconds, and testing is usually performed over 30 seconds. This reflects the maturation of the athlete's glycolytic energy system. So here's a graph of data illustrating the development of peak power, that is the maximal power output in under two seconds. And the data is for the legs and arms of males that is shown in blue, and the females that is shown in pink. Peak leg power for both genders improves relatively linearly with age and is at its highest level around 30 years of age for males. Female peak leg power is still on an upward trend at 22 years of age, and could also possibly be at its highest peak at 30 years of age, similar to that of men. Arm power for males improves lineally up until around age 22 years, and then there's a plateau. Unfortunately, there's no data available for females after 14 years of age. On this chart, we have the mean power output over 30 seconds, and it shows a similar pattern. There's a linear increase in mean leg power until around 30 years of age for males, and the data for females is only available until 22 years of age. And once again, there is no data available for the female mean endurance arm power after age 14 years. Mean endurance power for arms is lower than leg power and appears to plateau for males around 22 years of age. So, here's a summary of the data for peak and mean power shown together so that we can make some comparisons. The chart at the top is for males, and the chart down on the bottom is for females. During the younger ages, peak and mean power for both genders are similar. Neither has a peak power that is substantially different from their mean endurance power for either the legs or the arms. And if you follow the solid line, that is the peak power, and the dotted line, that is the mean power, both peak and mean power increase with age with a gradual bigger rise in peak power over mean power. And this is true for the legs and arms of both genders. However, we, again, don't have data for females after age 14 years. But based on the upper body strength data that we discussed in a previous module, we might surmise that female peak and mean power for upper body strength may not differ with age. When examining power in terms of kilogram per body weight, that is when we eliminate the influence of growth, there is an increase in peak power of the lower body with age for both genders. Although, it's not a smooth increase for the males. Upper body peak power for males continues to improve with age until about 22 years of age, and there is no upper body data after 14 years for females, unfortunately. While peak power per kilogram of body weight of female muscle continues to climb with age, mean endurance power plateaus after age 13 years. The data for male also suggests a mean anaerobic power plateau after age 15. Now what this means is not exactly clear. The interpretation of the data leads to different conclusions for peak and mean anaerobic power. Relative peak power continues to improve with age even when we remove the effect of the influence of muscle mass. Peak power, remember, involves more nervous system coordination and control than mean anaerobic power does. The nervous system is quite mature before puberty, however, the control aspect of the nervous system is not fully developed until late into adolescence and even beyond. And we're going to discuss control more in the next module when we discuss coordination. Improvement in control could explain the continued increase in relative peak power with age. It is since the brain is able to better coordinate this and fire more muscle fibers to produce an explosive performance as the child gets older. Mean aerobic performance, however, depends on the maturity of the glycolytic enzymes. And the flat line on the graph indicates that glycolytic enzymes appear to be fully functioning around 13 to 14 years of age. The improvement in total mean anaerobic power with age, therefore, appears to be due to the increased muscle mass. With age, the child has a bigger muscle mass, and this provides him with more power output. Now just to complete our data analysis, the absolute peak leg power of females is 40% lower than that of males. In this case, absolute power refers to the total power the child can produce. However, when comparing the lower leg power per kilogram of body mass, female power production is just 15% lower than that of the males. These studies, the fat was not factored out, so the remaining difference could be due to the inability to compare pure muscle mass of the two genders. Now, there's a lot we don't know about the peak and mean aerobic power of females as is clear from these data.
