 |
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.
MORE RESOURCES:
|
Emergency exercise set for Maine SouthNorridge Harwood Heights NewsMaine South High School and city of Park Ridge public service personnel will conduct an “Active Shooter Exercise” the morning of Feb. 14 at the high school. The drill's purpose is to gauge how Maine South and Park Ridge emergency personnel would ...and more » |
|
A well-exercised heart is an efficient heartEast Valley TribuneExercise strengthens the heart muscle just as exercise strengthens other muscles of the body. A well-exercised, well-tuned heart does not have to beat 80 times a minute. It can beat less frequently while still supplying sufficient force to accommodate ...and more » |
|
SWAT team prepares for anything during training exercisesGreen Bay Press GazetteBrown County SWAT team training exercises in De Pe...: The Brown County SWAT Team utilizes a vacant St. Norbert College-owned house at 324 College Avenue in De Pere to do multiple search and arrest training exercises. Twenty-three officers and one ...and more » |
Google News
|
|
|
|
RELATED ARTICLES
Weight Loss and Exercise in Tough Environmental Conditions
Working out is working out, right?Wrong.Depending on the environmental conditions where youlive, there may be extra precautions that you'll want to consider when trying to lose weight by following a healthy diet and weight loss program.
When Exercising Right Looks Wrong III (Back)
Hopefully, if you read my last article I got you thinking. Thinking about different ways to train, not necessarily using machines, but using your entire body with each exercise.
When Exercising Right Looks Wrong
For most of us we live in a black and white world. Good vs.
Arthritis Exercise - One Way to Relieve Pain & Stiffness in Your Joints (part 1)
Exercise can be very beneficial for arthritis sufferers, often relieving stiffness in joints, strengthening muscles thereby reducing stress on joints, keeping bone and cartilage tissue strong and healthy, and increasing flexibility. A recommended 30-minute minimum of daily activity is the norm.
Attention, Ladies!
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.
Stay Mentally Focused When Training
When you decide to exercise, try to really stick to your training routine and don't get sidetracked by too much socializing. When you socialize with friends, your mind usually starts to wander off and you really start to lose focus on your main objective, which is to train hard and get out of there.
5 Ways to Fit Fitness In
Five points to consider when you want to fit fitness into a hectic lifeWhen I tell people what I do for a living, many will tell me they wish they had the time to exercise, but just can't seem to fit it in. This is one of the biggest excuses people give for not making exercise a part of their life.
Exercises You Probably Dont Do But Should!
This is going to be kinda short and sweet. .
Workout Without a Gym
You may also have no access to a commercial gym, home gym or are on business trip, but there can be a solution, a strength-training workout without the need of expensive machines.As with any exercise, whether you are using your own body weight, machines or free weights, if the resistance doesn't increase, your muscles won't be worked to their maximum capacity and the stimulus these fibres need to grow will be missing.
Is Exercise Making You Feel Worse?
I'm sure you've heard the following statement over and over
again: exercise can help you to beat stress, or alleviate
anxiety or boost a depressed mind. This is only true in
part.
5 Little Known Benefits of Warming Up & Cooling Down After Exercising
While working out in the gym, I have noticed that many exercisers
tend to skip two very important parts of their workout. It is
crucial that exercisers starts with a warm-up and ends with a
cool-down.
STRETCHING; Why Should I?
This short article looks at some of the tips, tricks and helpful hints you can use to help prevent sports injury and do-away with stiff, aching muscles & joints. It's been put together to answer some of the more common questions we get regarding stretching and sports injury, and details a number of useful sports injury prevention techniques.
What is Pilates?
Pilates is a system of over 500 controlled exercises that engage the mind and condition the total body by using a popular exercise regimen that uses special stretches and machines. Named after Joseph Pilates, Pilates exercise system has proven itself invaluable not only to the fitness user, but to the professional trainers as well.
How to Pick a Good Personal Trainer
One of the major benefits of the YourBestBodyNOW
Program and several other programs like it is that you can lose weight and meet your fitness and weight loss goals
even 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 absolute
maximum benefit.
No Time For The Gym?
As you have undoubtedly heard, college students around the country are gaining weight at a rapid rate. A recent study by Cornell University found that on average, college freshman gain about 0.
A Fitness Mothers Time
So you've been a mother for a while. Good for you, mothers are important.
Take a Break
Writing is a strenuous creative activity, and like physical activity it produces fatigue that requires rejuvenation and renewal, so when the mind is blocked, it is time to rest it. Many writers call this 'writer's block' but others claim that no such state exists.
Core-Principles: The Function of Functional Training
Okay?okay?okay! Enough already!!! It seems like with every new term, every new invention or just about anything that is seemingly not "Everyday" that we all become flustered and assume we know nothing, which is both a testament to our lack of faith in ourselves and also a reflection of our ever-growing dependence on externals to give us a little reassurance where our natural instincts should be in high gear.My intention with this article is not to offend anyone especially those that whom, without their continual support I would surely be seeking a new line of work, and yes I am referring to my clients, so please don't feel like I'm bashing "you" if I ever refer to any particular individuals or events, no names will be mentioned though.
The Benefit of Back Exercises
Back exercises are often prescribed effectively as an alternative to surgery. Doing daily back exercises can significantly reduce back pain related to a variety of common ailments.
Exercise Tips
Exercise TipsThe most effective exercise regimen includes both strength training and cardiovascular (aerobic) training in a consistent, regular program. 2-4 days of strength training and
2-5 days of aerobic activity; or
3-4 days of circuit training.
|
