VO2 Max- Exposing the Myth
VO2 max is defined as the maximal amount of oxygen the body is able to extract and use to support work performed by the body. It is therefore an indirect measure of the aerobic power of the body, which is controlled by complex interactions between neural (brain and nervous system), cardiovascular (heart and lungs) and skeletal muscle factors. The equation for VO2 max it is equal to the product of stroke volume (the maximum volume of blood the heart ejects in a contraction) and the arterio-venous difference (the difference between the saturation of the arterial blood and that of the venous blood). The aerobic power of the body will change constantly throughout a well-designed running program due to physiological changes and therefore its usefulness in designing a program and determining running capabilities is questionable. This article aims to explain the reason VO2 max is a better indicator of fitness levels than running potential and conditioning program design.
Many physiological adaptations occur as one becomes more fit, some of these include: an increased size and efficiency of the heart, increased blood volume, increased muscle capillarization (more capillaries developed) and increased mitochondria (small bodies in the muscle cell that use oxygen to burn fat and make energy) density. So it should be obvious then that if we increase the stroke volume or the a-v difference (or both), the VO2 max will increase. With a more muscular heart and an increased blood volume you may increase the stroke volume and with a greater extraction of oxygen from the blood at the muscle level (more mitochondria) you can increase the a-v difference, which equals a higher VO2 max. Thus, VO2 max is a good indicator of physical condition or fitness.
The question arises whether it is beneficial to know your VO2 max to develop an ideal training regimen or whether a high VO2 max automatically determines you as a great runner. From evidence accumulated by Prof. Tim Noakes and his colleagues at the Sports Science Institute of South Africa the answer is that knowing your VO2 max will not answer either question. Here's the explanation according to Dr. Andrew Bosch at the Institute. Dr Bosch questions whether VO2 max is genetically determined (i.e. an athlete with a high value has muscles that are capable of utilizing large amounts of oxygen and has a cardiovascular system capable of delivering this quantity of oxygen). This athlete can then run at a maximum aerobic speed that can be sustained by this amount of oxygen. If VO2 max was determined genetically, then it would make no difference if the athlete was highly unfit or superbly fit since the result of the test would be the same. However, it should be intuitively obvious that a fit and more conditioned runner can run at a higher speed (higher power output) on a treadmill than when unfit. Dr. Bosch suggests that in this situation the (high) VO2 max value would be attained at a very low running speed, which would be impossibly inefficient.
Dr. Bosch confirms the common knowledge that oxygen demand increases incrementally as the speed (power output) of the runner increases. This increase in oxygen consumption continues until the athlete can no longer continue running at that speed and stops. The volume of oxygen consumed at that instant is termed the VO2 max and the running speed, the peak running speed. Historically, exercise scientists have attributed a leveling out or a plateau to VO2 max and that at the point this occurs determines the value. Research by Noakes and colleagues indicate that half of athletes tested in laboratories fail to demonstrate a plateau and that their VO2 or oxygen consumption is still increasing when they cannot continue further. This poses a question as to why these runners stopped if their oxygen consumption (the supposed limiting factor) was still on the increase. Prof. Noakes feels and is continuing to search for evidence that some "central governor" regulates the power output to the exercising limbs to help protect the body from "running itself to death" via a heart attack (see VO2 Max or the Brain?). The fact that oxygen consumption continues to increase until ultimate fatigue indicates that as the fitness level of the athlete increases and he is able to run faster, so does his VO2 max. Therefore, the inability to use the VO2 max test as a predictor of future performance of an athlete that can still improve his running by using a scientifically devised program becomes obvious - a great training induced increase in running speed (decrease in race times) will transfer into a substantial increase in VO2 max and visa versa. Even knowing the peak speed is unlikely to help an individual for the same reasons and also possibly because of the unlikelihood of being able to sustain such a speed/intensity for the duration of a long distance run.
Professor Tim Noakes feels that running economy is the true measure of performance. Running economy is the relationship between maximal power output and oxygen consumption. Good running economy in this context means that a highly economical runner may actually achieve a higher treadmill speed or power output at a relatively low VO2 max and is therefore more efficient. A less economical runner will require a higher volume of oxygen to achieve the same power output. Noakes is proposes that biomechanical efficiency contributes to running economy - for example, a runner with good core stability will waste less energy and power than a competitor with poor core strength that allows for inefficent movement. Also, Dr. Noakes considers superior runners to have superior fatigue resistance. That is, they have a superior heart that can maintain a high cardiac output at the maximum coronary blood flow and skeletal muscles that are efficient, elastic and possess a high degree of contractility.
Dr. Bosch concedes that even though it may be of little use in predicting running ability or program design, there are some uses for the VO2 max test. He advises that if a program is being designed for a beginning runner who has not run any races and therefore has no running times, a VO2 max test will give a good indication of the current condition of the athlete and how to base running schedules. Also, if performed regularly, a VO2 max test can give an indication of the effectiveness of the training program. Lastly, it is fun to compare own VO2 max to those of elite runners who often have values exceeding 70ml/kg/min.
David Petersen is a Personal Trainer/Certified Strength and Conditioning Specialist and the owner and founder of B.O.S.S. Fitness Inc. based in Oldsmar, Florida. More articles and information can be found at http://www.bossfitness.com
NOTE: You're free to republish this article on your website, in your newsletter, in your e-book or in other publications provided the article is reproduced in its entirety, including this note, author information and all LIVE website links as above.
Exercise: Why YOU Should Do It
Hundreds of Thousands of Americans spend millions of dollars each year on diet pills, "magical" exercise devices, and misrepresented health and fitness products, when in all actuality a good set of dumbbells and a brisk walk may be all you need to get in better shape than you've ever been in.What can you do with nothing but a set of dumbbells, you ask? Provide resistance to your body's movements - also known as weight lifting.
Benefit of Pilates
One of the main benefits of Pilates is it refreshes your physical and mental well-being. Pilates is a series of controlled movements that unite the body and mind and creates a direct connection to the muscles.
Weight Training: The Real Weight Loss Exercise
So you want to lose weight? Chances are, you'll spend the next few days "pigging out" while in the back of your mind you resolve that ..
Physical Fitness - Is Your Workout Missing Something?
Hiking along a rocky trail, two of the three friends carefully picked their way from rock to rock. But one leaped from rock to rock, bounding by the others like a gazelle running and leaping from rock to rock.
Get Moving...The Benefits Will Last a Lifetime!
The benefits of physical activity are numerous and very well documented. Aside from substantially reducing the risk of dying of a heart attack, regular physical activity decreases the risk for stroke, diabetes, high blood pressure and certain forms of cancer.
How to Pick a Good Personal Trainer
One of the major benefits of the YourBestBodyNOWProgram and several other programs like it is that you can lose weight and meet your fitness and weight loss goalseven if you have neither the time nor money to get a personal trainer.At the same time, if you do ultimately decide to hire trainer at some point,I want to make sure that you are going about it in a way that will bring you the absolutemaximum benefit.
The Top 10 Reasons Why Your Dog is a Great Workout Partner
1) He or she is never late for a workout session. Chances are good that your dog lives with you and has a reasonable clear schedule.
Six Simple Strategies to Turn Your Walks into Workouts
If You are already fitness walking several times a week - great! Now its time to step it up a bit. Here are 6 ways to turn your walks into workouts.
Top 10 Mistakes To Avoid When Exercising the Abdominals
The abdominal muscles are essential for maintaining good posture and core stability, however many exercisers are unclear on the correct way to exercise them. Traditional exercises for the abdominals include crunches and sit-ups also known as trunk curls and curl-ups.
Professional Triathlon Training Taking You To Your Best
There are hundreds of different programs for professional triathlon training that will work for you. There are even more that won't.
Benefits of a Good Training Journal
Most of us have trained at one part in our lives. Chances are if you've ever taken your training seriously you've used a training journal or a training log.
Building those impressively sleek shoulders takes a great deal of raw grind but once you sport a shapely set, you'll quickly be separated from the rest. If you like to wear bikinis or summer dresses that reveal your upper torso, shoulder training is ideal in sporting a sexy physique.
Bodybuilding and Exercise - The Ten Commandments in Making of a Champion!
1. Fill your life up with different hobbies! - Bodybuilding Champions realize working out is not everything there is in life.
Super Charge Your Metabolism
1. Cardio in Combination with Strength Training- If you need to combine your cardio with Strength training then do your Cardio AFTER your Resistance Training workout.
Tips To Deal with Exercise Induced Asthma
For approximately 80-90% of people that suffer from asthma, exercise can be a strong stimulus for an attack. This syndrome has become known as exercise induced asthma or EIA.
Bodybuilding Training Tips - To be a Champion!
Twenty two years ago I fell into the world of bodybuilding by accident. I had absolutely no discipline, determination or confidence in myself.
Exercises You Probably Dont Do But Should!
This is going to be kinda short and sweet. .
Speed Training With Intensity - Bound To Get Faster
Bounding can be a great addition to your high intensity workouts - and it's essential to getting faster.I remember the first time that I ever bounded for speed.
How NOT to Return from an Exercise Break
Several sites, including this one, recommend that you take a break every 8 weeks after working out with weights. But how do you come back from that break and get back into your routine?Does anyone suggest you just jump back in and do the same intensity as when you last left off? Definitely not.
Lance Armstrong's Training Tactics - The Tortoise or the Hare?
I have been counseling people on weight loss, exercise efficiency and nutrition for over twenty years. Every time I go to the gym I observe people, their training tactics and their workout habits.