Echocardiography Evidence of Cardiac Output Training

The information in this article originally started as something I was looking at for my own interest. I then decided to share the information on Joel Jamieson’s forum.  When Joel saw it, he contacted Landon Evans. Landon then contacted me, so here we go.

First, my background. I’ve been training since high school (20+ years). I started lifting for football, and the weight bug bit me for good. Since then, I’ve dabbled in different types of strength training -- powerlifting, Olympic lifting, strongman, bodybuilding, etc...all on a non-competitive basis. About 7 years ago, I managed to free myself from the commercial gym mess and train at home, but I used this as an excuse to neglect my cardio training since I didn’t have any pieces of cardio equipment. Working in the medical field, you would think I’d know better. I would occasionally do some interval type stuff, but I didn’t really stick with anything for very long.

In October, I completely ruptured my right bicep tendon at the elbow and had it surgically repaired. This was my first real injury. During the recovery, I decided to take it easy, allowing my body to rest by keeping activity light, and I started to formulate my plan for returning to full training. I had been reading about Wendler’s 5/3/1, bought the book, and decided that this was the way I wanted to go.  I also knew I needed to work on my conditioning, like he states, but I didn’t want to start the conditioning/hill sprints full bore from the start due to my age (37), weight (240 pounds at 5’11”) and the fact that I was basically starting from scratch.

First I would build an aerobic base, and then I would move on to the more intense stuff. This is where Joel Jamieson came in. I read his articles here, then went to his website www.8weeksout.com to find out more. His recommendations to increase cardiac output are to train for at least an hour a session at a heart rate of 120-150 for 1-2 days/week to cause eccentric hypertrophy of the heart (increase in chamber size, not wall thickness). The type of activity doesn’t matter (you can run, bike, swim, do bodyweight exercises, etc) so long as you keep your heart rate in the right range the entire time.

As Bruce Lee said, “Knowing is not enough, we must apply. Willing is not enough, we must do.” So away I went.

I decided to lift twice a week and do the cardiac work the day after each weight session. I started by staying in the low end of the heart rate range (120-130) usually by walking, or, in bad weather, by climbing my stairs (boring, but effective). I did this for several weeks and then decided to focus more on the conditioning. I needed to cut down to 3 days per week, so my lifting stayed the same, with my cardio following each lifting session. I then added a third day of cardio. I also started to push the heart rates higher by jogging until my heart rate hit ~140 and then walking until I got back down to 120, then repeating the process until I got my total time in (at least an hour). I also pushed the third day to an hour and a half when I could. As I got more conditioned, I pushed the upper limit heart rate to 150 and started raising the lower limit to 135, which also required me to jog more, eventually running, and walking less over time. Occasionally, I would give the running a break and do kettlebell swings/snatches, but 95% of the conditioning was running.

At the time I started the more intense conditioning, I had the idea that it would be neat to actually see the changes in my heart on an echocardiogram. I work at a medical office where I do cardiopulmonary testing, and I'm lucky enough to be able to get an echocardiogram (ultrasound of the heart) done just about any time I want, so I asked a co-worker if he would mind doing it for me. I figured it would be interesting to see what adaptations occurred to my heart from doing cardiac output work. This is when I had the baseline images taken (4/8/09). I then repeated them 9 weeks later (6/17/09) before I went away for vacation.

I’ll give the data and then try to provide a basic explanation of what each of the values signify.

Here are the echo numbers:

Some things to keep in mind:

1. Although these numbers are a good guideline for the adaptations occurring, they are estimates, which can vary due to image quality.  Fortunately, I have very clear images, but others (those who are obese, have lung disease, etc) may not. Also, you are trying to take images of a moving object (you can’t get the heart to stop to get the images), thus the possible inaccuracy.

2. This was not a complete echocardiogram like a patient would have done when referred by a physician. There were certain adaptations I wanted looked at for the left ventricle and was not interested in the other chambers, valve function, etc.

3. Nine weeks is a relatively short time frame to see significant adaptations. Again, I originally did this for personal interest and wasn’t intending to present this as an article. If I had thought of doing the images before starting any training, the changes would probably have been more significant.

4. I will give normal, non-athletic values for each measurement. These may vary slightly depending on your reference source.

5. It must be considered that the changes seen are physiological (training adaptations) and not pathological (disease).

Explanation:

When looking at left ventricle (LV) function, there are two phases to look at: Systole, when the heart is contracting, and Diastole, when the heart is relaxing (but this does actually require energy). As an example, when you have your blood pressure (BP) taken, there are two numbers given.  If your BP is 120/80, 120(mmHg) is the systolic (heart contracting) pressure in your artery and 80(mmHg) is the diastolic (heart resting) pressure. The top number will always be higher.

Looking at Systolic LV function, three main things are typically considered: ejection fraction, fractional shortening and cardiac output.

Ejection fraction (EF) is the percentage of blood volume in the LV that is pumped out with each heartbeat. Despite what some people may think, you don’t pump out all of the blood in the ventricle with each beat. Stroke volume (the amount of blood volume pumped out with each beat) is used in calculating EF.

Fractional shortening (FS) is the change in dimension of the left ventricle chamber from diastole to systole.

Cardiac output (CO) is simply heart rate multiplied by stroke volume. You will see there are no values given because I didn’t have this evaluated.

For Diastolic function, E/A ratio is commonly used.  Doppler echocardiography is used to measure blood flow through the mitral valve during diastole. If you look at the heart image above, you can see the mitral valve controls blood flow from the left atrium to the left ventricle. During the early phase of diastole, the LV myocardium (heart muscle) relaxes, causing a pressure decrease, which opens the mitral valve when the pressure drops lower than the pressure in the left atrium. This is signified by the E wave. During late diastole, the atrium contacts and more blood is pushed into the LV.  This is signified by the A wave. We then look at a ratio of the E wave to the A wave to determine how the LV functions during diastole.

Values are taken during diastole, unless otherwise noted.

LV Wall Thickness:

There were also two wall thickness measurements (diastolic values) taken to look for LV hypertrophy. Aerobic training typically causes a more significant change in LV chamber size than LV wall thickness. If you look at the values given, the septal wall thickness didn’t change (1.04 cm, expected result) and the posterior wall did increase slightly (0.94cm to 1.04 cm, somewhat expected result), which could be due to adaptation or variability in images. Again, these are estimates. Normal values are 0.6-1.1 cm for both.

Systolic Function Values:

LV chamber size increased from 5.31 cm to 5.83 cm during diastole. Normal values we use where I work are 3.7-5.6 cm. This increased pretty significantly, and puts me at a borderline dilated LV (physiological adaptation, not pathological).

LV volume increased from 135.9 ml to 168.5 ml. This correlates to the increase in chamber size.

SV increased from 100.4 ml to 116.3 ml. Normal values are 60-100 ml, with an average value of 70ml. This means that my heart is now pumping 16% more blood with each beat.

EF decreased slightly from 74% to 69% (the normal range is 55% or higher). This is actually good because it means that my heart doesn’t have to pump as hard (increased efficiency) since more blood is going out with each beat.

FS also decreased slightly from 43% to 39% (normal is above 30%). FS is looking at the same thing as EF, but in a different way. EF looks at volume of blood, FS looks at amount of change in wall dimension with contraction (diastole to systole). This again shows my heart is pumping more efficiently.

Diastolic function:

The E wave went from 0.60 m/s to 0.75 m/s. This signifies that my heart is dilating/stretching more during diastole. The A wave went from 0.41 m/s to 0.38 m/s. This signifies that the atrial contraction is providing less of the filling of the LV during diastole. The E/A ratio increased from 1.46 to 1.97. Generally, you want the E/A ratio to be greater than 1.0. These values signify again that my heart is more efficient.

Noticed benefits:

After seeing all the science, let me give you one more set of numbers and some perceptual information. During this time, my heart rate went from the low 70s on average to high 50’s - low 60’s, depending on when I take it. Don’t worry...Lance Armstrong has nothing to fear. My bodyweight didn’t really change, but my waist is smaller. I also feel more energetic, sleep better, get through my workouts quicker and recover better from them, get less agitated at things, and overall just have a greatly improved sense of well being. This just shows the value of this type of training. Don’t skimp on it.

Summary:

What started as an experiment on myself turned into an article for EliteFTS. Pretty cool. I have now started some more intense conditioning and will re-evaluate myself in a few months to look for further changes (another article possibly?). I would like to thank Joel and Landon, and I would also like to thank my co-worker Kevin for agreeing to take the echo images.

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