Stroke Volume and V02 Max?

[MVP]

I'm having trouble understanding how to measure these two.

Strong volume = amount of blood that leaves each ventricle each time the heart beats and is necessary in order to create a client sufficient aerobic exercise. BUT, how do you measure it without some sort of machine?

How do you measure V02 Max?

Thanks for the replies.

[Aoife]

They do it with machines.

[fengshway]

stroke volume is measured by a cardiologist using a test called an echocardiogram--basically an ultrasound of your heart. it measures the volume of blood that your heart pumps out with each contraction. athletes have a high stroke volume, and are healthy, so usually this is not a variable that is measured for healthy people.

VO2 max is the amount of oxygen that is utilized at maximal effort or near max effort--it is measured on a treadmill by a cardiologist or an exercise physiologist. the athlete wears a mask while running on a treadmill or riding a stationary bike. this variable alone can help predict performance at endurance sports, but other variables are critical too, like lactate threshhold pace, running economy and a whole lot of other variables, some of which are genetically based and some which can be improved with training. VO2 max testing is relevant for competitive endurance athletes and recreational endurance athletes who are trying to improve.

[MVP]

Thanks for the replies.

So I won't have to measure those two alone?

Edit:- What about when I'm suppose to measure their cardiac output? Stroke volume X heart rate?

Thanks again.

[fengshway]

the two measure completely different things.

cardiac output basics

http://www.cvphysiology.com/Cardiac%...tion/CF021.htm

[LisaS]

Originally Posted by MVP

Thanks for the replies.

So I won't have to measure those two alone?

Edit:- What about when I'm suppose to measure their cardiac output? Stroke volume X heart rate?

Thanks again.

What do you mean "so I won't have to measure those two alone?"
What is the context that you think you need to be measuring these at all without a sound understanding of the physiology?
Or is this for some exam that you will be taking and you are trying to memorize the formulas and methods involved?

[MVP]

Originally Posted by fengshway

the two measure completely different things.

cardiac output basics

http://www.cvphysiology.com/Cardiac%...tion/CF021.htm

I know. But you must know the stroke volume to know the cardiac output. The cardiac output is the amount of blood that leaves each ventricle in each minute. The amount of beats X's the stroke volume. Or would the equations on the test give you the stroke volume and heart rate then tell you to calculate the Q?

When meeting with a new client, how are you suppose to read his Q then? Would you have to send him to a cardiologist to get his SV or is there a way to measure it in the gym?

Thanks for your reply.

Originally Posted by LisaS

What do you mean "so I won't have to measure those two alone?"
What is the context that you think you need to be measuring these at all without a sound understanding of the physiology?
Or is this for some exam that you will be taking and you are trying to memorize the formulas and methods involved?

I mean in real life. When getting a client, having to measure his or her cardiac output would require measuring the stroke volume as mentioned earlier. Q = SV X's HR. You'd have to know the stroke volume first.

I understand physiology, what I don't understand is the formula. During the ejection fraction of a resting heart beat the heart maintains 50% of the blood (from my understanding) and during systole (the contraction phase) only pumps out about 50% of the blood and the other 50% is kept in the heart during diastole that is pumped out a fraction of a second later. During aerobic exercise, the muscles demand more oxygen so the heart must pump more blood so the ejection fraction minimizes to less than 50% maintaining inside the heart during diastole.

In order to measure the stroke volume you'd have to know the amount of blood in ML's that leaves the heart with each contraction, differing between the resting heart rate and the working heart rate. But I still wasn't quite understanding how the amount of blood was measured, then I heard pulse pressure but I'm not sure I could accurately guess the amount of blood in ML's. I'm taking the ACE certification exam in a month and just wanted to make sure I have these formulas correct.

[fengshway]

I am a physician, and I know how stroke volume and ejection fraction are relevant when one of my patients has cardiomyopathy or some other reason for a reduced ejection fraction. it can change what meds I give them. my cardiologist colleagues measure and compute these things for me.

I have no idea how personal trainers use this information. one of the trainers will have to chime in to answer how they use this information on a practical level with clients. the personal trainers I know request a letter from a client's personal physician certifying that they are safe to exercise. some exercise physiologists I know might do some modified exercise protocols and compute recovery heart rates to test fitness. but I am not aware that they would use cardiac output in daily practice.

[Aoife]

That sounds like a huge amount of overkill and rather useless information for a healthy new client looking for some personal training.

[LisaS]

If you are thinking that you will be applying the detailed measurements from a lab in the gym you are likely mistaken.
I think you will find that the exam expects you to understand the formulas and apply them properly when given some lab values in a scenario type question like this:

Clinical problem 2 In the resting steady state, a well-trained jogger has an RQ of 0.8, end-tidal PCO₂ of 40 mm Hg, and a minute ventilation of 6 L/min. After 5 minutes on a treadmill at 2.5 mph, the following expired gas measurements are obtained: VCO₂ of 800 ml/min, VO₂ of 1000 ml/min, end-tidal PCO₂ of 39 mm Hg, and minute ventilation of 30 L/min. What are alveolar and arterial PCO₂ at this point?

You're not going to be doing any of that in a normal gym environment with a client.

[Barrett]

Also, for VO2 Max you can measure it on any piece of equipment, as long as you have a way of measuring the METS(Metabolic Equivalent).

[MVP]

Originally Posted by LisaS

If you are thinking that you will be applying the detailed measurements from a lab in the gym you are likely mistaken.
I think you will find that the exam expects you to understand the formulas and apply them properly when given some lab values in a scenario type question like this:You're not going to be doing any of that in a normal gym environment with a client.

OK. Thank you. The formulas in the book, so as long as I know the the formula to calculate the V02 Max and Q (Cardiac Output) I should be fine on the exam?

[LisaS]

haven't seen the ACE exam so can't comment specifically,but generally exams on ex phys want you to know the concepts and be able to apply the concepts and formulas properly - in this case, which formula to use to calculate or find out what you are being asked to find.

[kratos]

Understanding the basics of the cardiovascular system (hemodynamics in the case of this thread) is important to having a more thorough knowledge of how the body acutely and chronically responds to exercise/physical activity as well as the direct and indirect implications that has on health, fitness, and sport performance. However, few people outside of a clinical or research setting will: 1) need to know accurate values for variables like cardiac output and stroke volume and 2) have the equipment/resources to be able to determine such values. As a point of clarification, the only way to "measure" stroke volume, cardiac output, ejection fraction, and oxygen consumption is to actually go in there (i.e. the heart or its vessels) with catheters and directly collect the data (volumes, concentrations, etc.). Even cardiologists who need to know things like stroke volume and ejection fraction usually do it noninvasively with an echocardiogram and "eyeball" these variables based on changes in various cardiac dimensions and blood flow velocities. Many of them are, however, very good at this and their "eyeball" estimations might as well be measurements. I got to see this on a daily basis when I worked in a research division of a cardiology clinic as I was going through my doctorate program. Oxygen consumption (i.e. VO2) is also estimated (not "measured") using a metabolic collection and analyzer system that is based on something called indirect calorimetry. Yes, the inspired and expired gases are collected and analyzed for gas concentrations and flow volumes but the end piece of data (i.e. VO2) is still just an estimate based on physiology and hemodynamics that are beyond the scope of this discussion. That is not to say those estimations can't be very accurate, it simply means the term "measure" is not correct. It might sound like semantics, but it is important to know the difference. Long story made slightly longer: know the formulae, understand the relationships of the various components of each formula to one another, be able to talk about what it all means to your particular scenario (e.g. exercising client, clinical patient, elite athlete, etc.) and don't worry about having to know (or determine) indices like stroke volume and cardiac output.

Joe Warpeha
Assistant Professor of Exercise Physiology
Director, Exercise Physiology Laboratories
College of St. Scholastica

[Jean-Paul]

Not sure how this applies to personal trainers. My PAR-Q usually alerts me if I need to send someone to a doc for tests before putting them on a training program. I sure don't bother to test all that stuff myself.

If you want to learn a valuable skill for a personal trainer, learn some motion screens for various kinetic chain dysfunctions.

[shwillkid]

I was kinda wonderin about all this stuff too. I am currently reading/preparing for the NSCA CPT exam and all of the beginning chapters seem to be really specific w/ these types of things but the test modules say nothing about them. It seems to me that they just want you to have a basic background of the information but the test is mostly practical application stuff.

[Ryan71]

MVP,

You may find my article interesting:

http://www.elitefts.com/documents/ca...t_training.htm