Archives for August 2015

VO2 Max Test and Heart Rate Training

This post — like many of my posts — is long overdue. When it comes to blogging, I’ll be the first to admit I’m not very good at it. I tend to get long winded and want every post to be “perfect” before posting. Sometimes this leads to me NOT posting at all (PiYo Runners and P90X3 reviews to name a few. I’m terrible, I know.) But this topic is not one I feel I can ignore. There is a growing number of runners in the community who push well beyond their limits, and as a result damage is caused. I hope that sharing my experience will help someone to avoid the same mistakes I did.

Running is so simple and beautiful. However, the amount of injuries that sweep across the running community seem comical at times. It’s that same thing that makes running so simple, that can also make it so dangerous to our bodies. Anyone who has the will to run, can RUN – regardless of ever having a lesson. Nobody needs a lesson in running in order to pound the pavement. Sometimes a person’s will is stronger than the body — which can be a good thing — but sometimes it can push us too hard. Yes, YES there IS such a thing as pushing too hard. You see, my problem has never been that I don’t push enough, my problem is that I always push too hard. So this post is ENTIRELY directed at those who like to give 110% at life.

First, a Little History

My maternal Grandfather died of a heart attack suddenly at age 63, five years before I was even born. My mother suffered from high blood pressure from 1984 (when my childhood home burned to the ground) until 2.5 years ago. My maternal Aunt died from cancer when she was 55. My Uncle had a heart attack when he was 44 years old, 4 years later he had triple by-pass surgery. In 2006, he had another heart attack. Today he has multiple stents and a pacemaker/defibrillator. My youngest Uncle, had quadruple by-pass heart surgery at age 59. He passed away at age 65 due to pancreatitis and also had type II diabetes.

To type that all out is a bit eye opening, and scary. We have control over our choices, but we can’t choose our genetics. All of that history, is on my maternal side… my mother’s siblings. (My dad is an only child.)

I experienced these events from the outside looking in because so many of them were just part of life (never meeting my maternal Grandfather), and I was so young when some of the other events happened. Even still, they definitely played a huge role in shaping who I am today and why I am so passionate about health and fitness.

The first step is admitting…

It took me almost 3 years to admit the heart palpitations I kept experiencing were caused by my running; not stress, anxiety, food triggers or my occasional alcoholic beverage. Being the stubborn runner that I am though, I was in total denial. How could something that was “strengthening my heart be bad for me? I never wanted to connect the dots, despite having a whole map of them laid out before me.

It wasn’t until I went through a period of no running, crappy nutrition and emotional stress that I accepted once and for all it was the running. My paternal Grandmother passed away in December of 2014. We traveled home to spend time with family; which lead to eating like crap, sleeping like crap and feeling heartbroken at the reality of losing my last remaining grandparent. No palpitations though. Not a single one.

It was time to stop being stubborn and start making some changes.

I started reading the book “80/20 Running” by Matt Fitzgerald on the plane ride home from the funeral. So much of what he said made sense — that most recreational runners push too hard on the majority of their runs without realizing it. Instead of doing 80% of their runs at low or moderate intensity, they would do 80% of their runs at high intensity, with only 10-20% at moderate or low intensity. Recreational runners get caught up in pace.

We are innately built to want to push for a faster pace. Yet, when we train with a heart rate monitor we manage to keep our beats per minute under the recommended number. It’s an overall healthier way to train. Pace is good for pushing our limits during racing and heart rate is good for not going past our limits; to aid in recovery and maintaining proper fitness, without over extending.

I suspected I was pushing too hard on all my runs, despite thinking I wasn’t. In the past two years especially, I always felt I had become the type of runner who listened to their body and didn’t push too far beyond my limits. I felt I had a good balance. I was about to be schooled.

Dabbling in Heart Rate Training

In January of this year, I started wearing a heart rate monitor. I didn’t change much in regards to my running, I mostly just wanted to get a baseline. I also attempted a week of slow which Matt prescribes in the very first chapter.

“The point of the week of slow is to get you ready for 80/20 training by setting you free from your habitual pace and teaching you to embrace running slow.”

I was not — however — ready to embrace it. Not yet. Admittedly, I curbed the book for a while after that, but still wore the HR monitor. It went well and I did slow down a bit, but “thanks” to a couple of races, I started focusing on pace again.

In April I went on a trail run with one of my fast, strong runner friends. It was 91°F and I had the brilliant idea of doing a killer hill, twice. 941 feet of elevation gain. You can see in the graph below, that my average heart rate was 170 beats per minute (bpm) over the course of 6.5 miles. The grey blobs represent the elevation changes, blue is my pace, red is my heart rate.

Screen Shot 2015-07-14 at 10.08.19 AM


If you are new to heart rate data, the average max heart rate for someone my gender and age is around 183 bpm. Your max heart rate is when you are using 100% of your hearts capacity to pump the blood through your veins. So, my 170 bpm was using 89% — with my max being 184 bpm on that run. Needless to say when we got to the parking lot and finished our run, my legs were shaky and I felt very uneasy. The sun had set mid run, so the last half of the run was with headlamps, in the dark.


Over the next 3 days I had heart palpitations so bad, I thought my heart was going to pound out of my chest. Why did I let myself do this again? It was the final confirmation I needed to admit I was still pushing too hard, and that while wearing the HR monitor was a good first step, I needed to get serious about heart rate training.

80/20 Training Begins

By June 1st I had started the full 80/20 Running training plan. I mapped out the rest of my training for the year, based on races, vacations and 2 cycles of the half marathon training plans provided in the book. I made a goal to PR on my December half marathon in Tucson, but that I would do it the RIGHT way by focusing on heart health and low intensity runs.

For the 45 days in between starting 80/20 training and the torture hill repeats, I kept my HR under 160 bpm during ALL my runs. The heart palpitations slowly started to go away, and I noticed I was also less short tempered. Because oh yeah, having heart palpitations makes me anxious and therefore irritable. Once June 1st hit, I felt like I had been hitting the brakes enough in April and May, that I could tackle the actual 80/20 training plan. It was my month of slow, versus just a week of slow.

The first week kicked off with 6 days of running and 1 day of cross training. I had no idea if I’d be able to do it, but the whole goal of 80/20 running is to build a base slowly. Running every day at a low intensity is better for your form, your daily routine, your muscle memory, etc. than running every other day or even every third day at a high intensity (like I was doing).

One day while out there slowly chipping away at the miles, and trying to stick within zone 2 for low intensity (129-142 bpm) I kept thinking ‘How on EARTH is this going to help me become a better runner?!’

Then, I had a moment of clarity. 

I remembered my family history of heart disease, diabetes and cancer, and it hit me like a ton of bricks. My heart is my most important muscle to strenghten — not my legs, not my core or arms, but my heart. Working out every day at a slower pace, not straining my heart or pushing it to it’s max, was going to be more beneficial than what I was doing before.

It seems like absolute common sense now, and it was even hard for me to type that paragraph out… because I cannot believe this wasn’t a priority for me before. My priority was always to be healthy and run happy, sure — but I thought that by having certain pace goals, I was creating more health and strength. Never, did it ever occur to me, that I could potentially be doing more harm than good — particularly given my family history. I started to realize that my goal of a PR in December no longer mattered. That if I ever had hopes of another PR happening, I would first need to strip myself down to nothing and rebuild from the ground up. Past PR’s were just that, in the past — the old me. I was starting fresh; starting over. It was both scary and invigorating at the same time.

Taking it to the next level…

It wasn’t until my 4th week of heart rate training that I finally talked myself into getting the VO2 max test. Up until that point, I was using the talk test and the average HR zones in the 80/20 book as my guide. I was definitely trying my best to stay within the zones. But it created such a significant decrease in my pace, that at least every other run I would struggle mentally with pace — despite my lightbulb moment. I’m far from perfect friends. Also, for the record, I have decided not to share my paces at this time for multiple reasons, but mostly because I don’t want to discourage anyone from giving HR training a shot. If you really want to know, you can ask to follow me on Strava. If there is ONE thing I’ve learned with 80/20 running… it is NOT a quick fix; it is a huge, huge commitment that is a struggle to stick with every day I pound the pavement. Old habits are hard to break. Anyway, back to the test…

I hesitated to get the VO2 max test for so long, because I didn’t like the idea of running on a treadmill with a mask over my airways — it didn’t seem natural and I thought I knew my body better than a machine. I’d still argue that I do. However, I’m glad I went forward with the test despite my reservations, because I’m also a data geek when it comes to my running.

What is VO2 max anyway?

VO2 max is the maximum amount of oxygen that can be transported and used by the body, during intense physical exertion. It is used as an indicator of overall cardiovascular fitness and aerobic endurance. In theory, the more oxygen that is accessible to an athlete during exercise, the more energy they will have during those intense workouts. VO2 max testing is used as the gold standard for cardio fitness, because our muscles need oxygen for aerobic exercise and our blood carries that oxygen to the muscles via the heart. These things can all be measured during the VO2 max test.

By covering the nose and mouth with a mask, they can measure the air that is inhaled and exhaled. It can be done either on a treadmill or on a bike, depending on the type of athlete. The intensity increases incrementally until you reach exhaustion or maximal effort. There is a fancy equation that gets you to the below numbers, but I’m not going to attempt to explain that. Basically, the higher the number the more oxygen you can carry in your blood, to your muscles. 

Screen Shot 2015-08-02 at 6.56.07 PM

Click here for the men’s chart.

Cutting to the chase, my VO2 max was 44.2 on the treadmill. I have to say I was relieved when I learned that, because in addition to the heart issues in my family, I also have asthma. I’ve been determined in the last year to take myself off all prescription medications for it as well. I took Singular for almost 15 years straight! When I was in college I was taking a steroid inhaler, nasal spray, allergy shots, and allergy meds — it was ridiculous. In recent years, the only remaining medications were Zyrtec and Singular… but thankfully I’ve been off both of those for almost 8 months now. Of course I still carry my rescue inhaler with me on runs, but I’ve barely had to use it over the past two months. Before starting 80/20 training, I would use my inhaler before every run.

To have my test completed, I went to Endurance Rehab in Scottsdale. Anna Sanders did my test and from the moment we met, she made me feel comfortable about what I was about to endure. We talked for about 10 minutes before I even got on the treadmill.


This was my first time running on a Woodway treadmill too, and I ABSOLUTELY loved it. I finally was able to feel first hand what all the hype was about.

She explained everything thoroughly and made sure I would be comfortable wearing the mask. I said, “We’ll find out!”

After a quick walking warm-up on the treadmill, without the mask, she stopped the treadmill and placed the mask over my nose and mouth and securely fastened it so the seal around my face was tight. It didn’t bother me at all actually, so in my mind the worst part was over! This is where the test actually begins, and the treadmill was at a 2% incline. She started off at a very slow pace and asked me to give her my rating of perceived exertion (RPE), I gave a 3. She then told me she thought the readings were off, and that we needed to stop and refit the mask. We started back up again after she checked some things and she said we were good to go.

The whole time I felt very comfortable, not stressed and was really loving the Woodway! Anna would let me know every time she was about to increase the speed a bit, and every time I was ready for it. She did a really good job of keeping it positive for me. As we were nearing the end of the test, I felt like I could be pushing harder… she was giving me a visual of being at the finish line of a race and pushing to cross the line… it was at this point that I told her I could keep going, keep pushing harder… so she said, OK and increased the speed from 7.5 mph to 8 mph. In my mind, according to what I know I’m capable of when sprinting to the finish of a race, I still felt like I wanted that damn treadmill to go faster (I didn’t know the speeds at the time, just my PRE)! haha But instead she just kept me at that pace for a longer amount of time and eventually I felt myself hit the wall and max out. My final max HR during the test was 187 bpm.

I remained on the treadmill, hooked up to the mask through the whole cool down. Once I was done with the treadmill test, it was time to review the results. There was good news and bad news. She started off by saying I produced a “truckload of lactic acid”. To which I replied, my legs felt fine the whole time. haha She said it was because my brain was just so used to the feeling. That’s why she had to stop the test in the beginning, my readings for respiratory exchange ratio (RER) were completely elevated from the moment the test started. Rather than try to explain this in my own words, here is what RER is according to

RER – Respiratory Exchange Ratio

This is the ratio of carbon dioxide production to oxygen consumption (VCO2/VO2).  At rest and during low intensity exercise the RER reflects the type(s) of fuel substrates being used by the cells for the production of ATP (energy).  For example, an RER closer to 0.70 suggests that primarily fats are being used for the production of energy, whereas an RER closer to 1.0 suggests that primarily carbohydrates are being used.  During high intensity exercise some of the COthat the subject is blowing off comes from buffering of the blood and thus no longer reflects solely cellular metabolic events.  The normal range for RER at rest and during low intensity exercise is .7-1.0 but values may exceed 1.2 during high intensity exercise.

My RER values ranged from .99 at the start of the test to peaking at 1.49, during the first 45 seconds of the recovery segment. Ironically my RER was at 1.34 at my VO2 max. In essence, my body starts burning carbohydrates immediately during exercise, no fat gets burned for energy at all. Not good for an endurance athlete.

My numbers exceeded the normal range so much, because additional CO2 was being exhaled as a result of buffering within the blood to maintain a balanced pH. 

About a day after the test, Anna sent me all the final data in an Excel spreadsheet. It included new, personalized heart rate zones based on my VO2 max test. Below is the comparison of the average HR zones I was using, compared to my new zones. To say I was disappointed would be putting it lightly.

              Average     Corine’s
Zone 1   120-128      113 or below
Zone 2   129-142       114-140
Zone 3   153-160       141-144
Zone 4   163-168       145-149
Zone 5   169+            150+

It was hard enough for me to get into zone 1 and run at 128, but 113 or below? Are you kidding me here?! The first try at that didn’t go well at all. Not to mention, I was at elevation, wearing a hydration vest full of water and on a trail. Eventually, after about a week of trying I was able to find a pace where I could still run AND have my heart rate at or below 113. Granted, this is only for recovery runs and the first 5 minutes of every run as my warm-up, but still tough all the same.

Tomorrow I will be starting week 10 of my 80/20 training plan and I can say the journey — while difficult — has been worth it. I stumble often, but considering where I came from, I’d say I’m making huge strides. What’s most important to me is my health, not a PR. It sure has been hard getting here, so there’s no way I’m giving up on the process now. I will try to be better at keeping people posted on the progress. 🙂 I also plan to get retested in October or November to see if my RER has improved. Happy running friends!park_run_HR