Aerobic Power (V02max output)
This may sound like something a Marvel superhero would possess, but this is actually something we all possess.
Exercise Physiologists often look to a high V02max as the pre-requisite for success in endurance athletes.(Katch, McArdle, katch). First, what is V02max? V02max is maximum rate of oxygen consumption (uptake) measured during an increasing exercise intensity. Up to a threshold, the harder you work, the more oxygen you uptake. Aerobic power is essentially a synonym for the same concept. Athletes who sustain intense exercise for longer periods of time possess large aerobic capacity (Katch, McArdle, Katch).
The amount of oxygen your body uptakes to accomplish an exercise can also determine how many calories you are expending. Every exercise out there has a different relationship between the Aerobic Power (V02max) it uses, the ability to sustain that oxygen output, and the efficiency in completing the task. We will address some of these variables. Generally speaking, 1.0 Liter of oxygen output by your body is equivalent to 5.0 kcals expended. So breathing a bit heavy is a very good thing for your heart, lungs and calorie burn!
Defining Energy Economy
Exercise Economy is important in relation to Aerobic Power because it is the “quantity of energy [needed] to perform a particular task relative to performance quality ” (Katch, McArdle, Katch). If you ever had a coach for an endurance event, your coach probably told you something like, “Don’t waste your energy to get to the end. Be efficient. Focus on what’s important.” Increasing your exercise economy would mean that you have an ease of effort, don’t waste energy where it isn’t needed, and that you are not putting out as much energy as your event would usually demand. Pretty simply, as cardio-respiratory fitness goes up, exercise economy goes up, and Vo2max goes up- but here’s the little catch. At a certain threshold for trained athletes, your V02max will start rising at a slower rate. Again, the more trained you are, the less oxygen you uptake to do the work but the more oxygen volume you will put out. Your body becomes more trained, needs less oxygen to do the task, yet will in total expend more calories and oxygen all together. For example, if an athlete could run at a higher V02max than competitors, in less time, with greater ease, this would be a clear edge over other athletes.
Let’s Break down how these variables adhere to each mode of exercise:
Walking is a relatively easy effort exercise. It is one of the most basic movements all humans have been designed to accomplish. Some benefits to walking are:
-Slower movement speed
– Lower amount of muscle fibers recruited
– Slower twitch type of muscle
-Less energy demand is placed on the heart and muscles
Your economy should be relatively low to moderate, with oxygen output low as well as oxygen intake is low. The good news is, you can keep the same speed and economy, and just go up a hill to greatly increase your V02max as well as oxygen intake. Even so much as adding a slight hill will increase the work demand and energy output, even if you are walking the same speed. This will up your Oxygen demand as well as calorie demand without needing to put any unnecessary stress on your joints.
Running: Increasing your exercise economy!
According to Katch, McArdle and Katch, persons who compete in running, swimming, biking and other high energy demand sports have nearly twice the aerobic power as sedentary individuals. But the more trained you are, the less oxygen you will consume to produce those results…this is the best of all worlds! “At a given sub-maximal speed, of running, cycling, or swimming, an individual with greater exercise economy consumes less oxygen.” (Katch, McArdle, Katch). Imagine all those added benefits!
Benefits of Running:
-Larger muscle groups incorporated
-Multi-joint movement pattern
-Faster movement speed, force
– Increased oxygen demand
-Increased energy demand
-Faster twitch fibers recruited
When training at a higher level of energy output, your Aerobic Power can elevate from 6-20%, with increase seen as high as 50% above pre-training levels! Running no doubt gives you an exponential V02max boost to your aerobic routine. Pair that with higher efficiency/economy, and you are getting all the cardio-respiratory benefits along with efficient calorie burn.
Fun fact: Elite distance athletes, as a group, run with 5-10% greater economy than well-trained, middle-distance runners.
We here at Princeton Longevity Center hope that you learned a lot today about Aerobic Power (V02max output), exercise economy, and how the two relate to walking and running!
Katch, Victor L., et al. Essentials of Exercise Physiology. 4th ed., Wolters Kluwer/Lippincott Williams & Wilkins Health, 2011.