Build High Aerobic Capacity

Build High Aerobic Capacity

            One of the first things to realize as an educated endurance athlete is that there are abilities that can make your performance increase dramatically without too much influence on your appearance. There may be two athletes that are the same height, weight, lean body mass and even muscular coordination through seasons of training, but when asked to run a 5k on a track one athlete leaves the other in the dust. This example may lead a person to contemplate the question, “what is making one runner faster than the other”? Often an answer is given with one word, GENETICS. Genetics is the fundamental fabric of our lives supplying beneficial or non beneficial characteristics for our bodies. If you were to ask professor Joke Phd here at BYUH, he would tell you that “if you want to be one of the best endurance athletes, you need to have the right type of characteristics of a distance runner”.

            Though the two runners from the example above may both have the same percentage of lean body mass or muscle mass, they may have different types of muscle fibers in their limbs. Having different types of muscles may play in important key in performance. We see this often in Track & Field. The top class sprinters and top class endurance runners differ in the amount of slow twitched muscle fibers. This example helps demonstrate the difficulty in visually trying to choose distance runners out of a group of athletes.

            One of the easiest ways to identify good endurance athletes out of a group of people would be is to perform a VO2Max test on those individuals. The results of this test will tell you how much oxygen can be pumped into an athlete’s body to help perform work. There are many factors that create an athlete’s VO2Max including cardiac output (stroke volume x heart rate), lung diffusion, muscle metabolism and blood’s carrying capacity for oxygen. When seeking to determine which factors are the most important, Midgley et al 2006 concluded that, “It appears that changes in Stroke Volume (most importantly) and widening the Maximal Arterial-Mixed Venous Oxygen Difference of a runner are the most important factors in Increasing one’s Vo2 Max.”

            In my physiology class this last semester, I was surprised to see that even EXS (exercise and sport science) majors here at BYUH had confusion understanding what stroke volume was. Stroke volume is the amount of blood that a person’s heart pushes with every contraction. One may notice that top class endurance athletes have very few beats (perhaps 30-50 bpm) compared to the average individual (55-70 bpm) when at rest. The top class athletes are able to have much fewer beats per minute because with every single pumping of the heart, significantly higher amounts of blood are being pushed through the body. Having a physically larger heart is helpful in optimizing your performance as a distance runner. If a certain person has a stroke volume of 120 ml per beat and has a heart rate of 170 beats per minute then their total amount of blood being transported throughout their body would be 20,400 ml or 20.4 liters of blood in one minute. If another person with a weaker heart was only able to pump 70 ml per beat with the same heart rate of 170, this person would only be able to move 11,900 ml or 11.9 liters of blood through their body. That is 20.4 L compared to 11.9 L which is 1.7 times more blood per minute.

            To review what we have discussed so far, superior endurance performance is not always visually identifiable from the naked eye. One way to see if an athlete would be a good distance runner would be to check the strength of their heart. To check the strength of their heart, a VO2Max test can be performed. A strong heart is able to pump large amounts of blood with every beat.  This is how far we have got. Next it is important to realize why pumping large amounts of blood helps athletic performance.

            Within our blood we have red blood cells that contain hemoglobin which attaches to oxygen while in our lunges in what is known as the pulmonary capillary network. From here the continuous pumping of the heart circulates the blood now carrying oxygen. Oxygen is required for our bodies to accomplish aerobic work. Because aerobic work produces no significant waste products, high levels of activity can be maintained for long periods of time without our bodies getting tired. The only waste product produced, in fact, is CO2 carbon dioxide, which we breathe out during our exercise. Due to its efficiency, it has been estimated that around 90 percent of the energy requirements are met through aerobic (oxidative phosphorylation) methods during a 10k race for elite runners.

            This section is dedicated to teaching individuals on how to increase one’s aerobic capacity or VO2Max. If I were trying to increase my own VO2Max, what would I do? Well, I would remember Midgley et al 2006’s quote from earlier which states that the most important method of increasing one’s VO2Max is to increase one’s stroke volume…  So stroke volume appears to be the largest factor in determining one’s VO2Max. How can I increase my stroke volume? An interesting study was produced in 2007 by Helgerud and his associates entitled, Aerobic Power Training from the journal of Medicine and Science in Sports and Exercise. It was discovered that when different types of workouts were compared, high intensity intervals were the most effective way of increasing both stroke volume and VO2Max. These findings were supported with previous findings found by Laursen & Jenkins (2002) which stated, “It seems that, for athletes who are already trained, improvements in endurance performance can be achieved only through high-intensity interval training (HIT).”

            When researching different aspects of endurance training I often found many different interesting studies that had been done. If a person ever gets a chance to read Lore of Running by Timothy Noakes it is easy to become amazed at how many studies have been documented in relation to one seeking to improve their endurance performance. In my previous versions I had added sections entitled “final thoughts” on the different discussion topics. Some of the final thoughts that are interesting regarding the discussion of VO2Max are some of the following:

·         Elite Runners often do not change their VO2Max very much in later years of training.

·         After about 2-3 weeks of no training one’s VO2Max starts dropping significantly.

·         In general, if an athlete is not either increasing duration or intensity in a training program their VO2Max will plateau.

Estimates of one’s VO2Max are JUST ESTIMATES, in order to calculate one’s actual VO2Max one must be measured using lab equipment that monitor’s the actual amount of oxygen. So many times I hear of second-rate studies suggesting a change in VO2Max of participants when no measurements of Oxygen were ever even considered. Increased performances in distance running does not guarantee any change in one’s VO2Max, it is possible that a person got faster though other methods.

VO2Max is measured by ml/kg/min positioning the average male adult near 45, female near 38 respectively. Endurance athletes are higher generally placing world class men at around 80 or higher and women around 70 or higher. I have been measured at 70 ml/kg/min a couple years ago when I was running around 26:15ish for 8k. One thing that is important to understand about VO2Max is that depending on how a person is being tested, one’s VO2Max value will change. If I am a runner and am asked to be tested on a stationary bike rather than a treadmill, my values may be a couple units lower than if I was to do the test running.

These are my thoughts on instructing a person on optimizing their aerobic capacity. I hope some of the things I have shared helped you.