Wednesday, May 23, 2012

VO2 Max Test Results

Three years after my first VO2 max test, I decided it was time for another one, so I had this done last night.

What is this test?
A VO2 max test tells you how your body consumes oxygen and burns calories during exercise. It also identifies your heart rate zones so that you can train at paces that are most beneficial for your body, as opposed to looking at standardized chart (which may or may not apply to you).

The test is not fun. You warmup for 15 minutes on a treadmill and then put on this mask that's attached to a computer. The computer is measuring your oxygen intake and carbon dioxide output, and from that it can tell all sorts of things. You also wear a heart rate monitor, which is closely watched by the person performing the test. Once the warmup is complete and the mask is on, the person performing the test gradually increases your treadmill speed. In my case, it was 0.2 MPH for every minute. I started at 6.0 MPH and after 10 minutes, I was at 8.0 MPH. Eventually, he also ups the incline along with the speed. The test continues until you can't take it anymore.

The fact that you are running at a high intensity on a treadmill is bad enough. Add the mask in there for additional discomfort and you're really not having fun.

Why take such a test?
My heart rate during the test.
The test provides information that will help you tailor your training. Most critical are the heart rate zones. Using the standard "percentage of max" does not work for every athlete because every body is unique in its oxygen consumption. I've been training with a heart rate monitor since I took this test in 2009, and it's really helped guide my training paces. When it's super hot outside, the heart rate is higher, so I go slower. I'm also more in tune with my body. I can tell when I'm having an off day if my heart rate is abnormally high for the paces I am running. Or if my heart rate is telling me that I need to go much slower than on other days.

The test also provides information that can help with your nutrition plan and lets you know if you need to focus more on speed or endurance.

My results
I have to say, I left the testing location feeling discouraged. Three years ago, this guy told me that I was among the 10% of runners who are more built for endurance than speed, and that I would do better at marathons and half marathons. And I guess back then it was true. My half marathon PR at the time was 1:44:04, but I still had never broken 49:00 in the 10K or 23:00 in the 5K. Yesterday, I learned that the reverse is now true. I am currently in much better shape for short races than long ones. I have a high lactate threshold and I've increased my VO2 max. But my treadmill pace for "easy" was actually slower.

However. . . back in 2009, I did the majority of my runs on a treadmill so I was more comfortable on the treadmill. Last night, my feet hurt right off the bat, and my calves and hips were killing me by the end. In fact, it was my legs hurting me that was the limiting factor and that made me stop the test. So, I really can't compare a treadmill time from 2009 to now, when I do 100% of my running outdoors. But still- it was discouraging that my easy pace was 20 seconds per mile slower on the treadmill than it was three years ago.

Interestingly, Greg's results have also gone in the opposite direction. Back in 2009, he was better trained for speed, and now apparently he's much better trained for endurance. Far better than I am. We always thought that I was the endurance queen and he was the king of speed, but according to this test, the roles are now reversed. His easy pace is faster than mine. I hope he'll still do long runs with me!

The results do make sense. Greg hasn't PRed at a short distance in over a year, but is killing the long distances. I haven't PRed at a half marathon or marathon in over a year, but I'm doing well with shorter stuff.  The guy said that Greg didn't leave anything on the course with his 1:13 Cherry Blossom time. He said that my 1:15 time was soft, and I should have beat Greg. Ha!  This confirms what we've always known--  Greg can really redline it, and I am a wimp at pushing. :-)

It's great that I've increased my VO2 max because that's mainly a factor of genetics, and it decreases as you age. It's one of the hardest elements to change/control.  But hey, I'm three years older, the VO2 max is 3 points higher!

Of course, my heart rate zones have changed. This isn't really a reflection of fitness, but more of age and other physiological factors. Before the test, I actually predicted that the top of my Zone 2 (the "easy zone") was now 162 as opposed to the previous 165. Every time my heart rate gets above 162, I notice I am working harder. 162 and below is easy street, but it used to feel that way at 165 and below. Confirmation that I am in tune with what feels easy vs. slightly harder than easy. Long runs will now be in the range of a 150-162 heart rate.

Fat Burning
Finally, I learned that my body is not effective at burning fat as fuel. In fact, in 2009, my body was burning twice as much fat as it does now for the same paces. This might explain my recent weight gain over the past 4 months. This makes sense because in 2009 I would never eat anything before my long runs. For the past year, I have been having a bagel with peanut butter before each long run, and my body has been using that as fuel instead of fat. I think going forward I will rely on last night's dinner for my fuel, unless the run is 16+ miles, and I will eat a smaller bagel with less peanut butter. And be sure to eat it at least two hours in advance. Eating within 2 hours of a long run causes your insulin levels to rise, and so your body uses that glucose as fuel-- not the fat. It's important for the body to use fat because it's a better, more readily available source of energy than glucose-- especially in a marathon.

Training Volume/Mileage
In 2009, I was coming off a long training cycle averaging about 50 miles per week, peaking at about 60. Since my stress fractures in January of 2011, I have been keeping my weekly mileage in the 30's and 40's. My training for Shamrock averaged in the low 40's. I thought this was okay because I was supplementing with swimming and pool running. Also, I ran Shamrock in 2008 on low mileage and it was a great race for me. However, these results indicate that I probably need to pump up the volume, so to speak. More volume means my body will be better able to burn fat as fuel.

The test administrator also suggested longer tempos. My coach prefers 3-4 mile tempo runs and I can't remember the last time I went beyond 4 miles. They've gotten super fast, but  yesterday I learned that I would get more benefit out of 5-6 mile tempos at a slower pace (still staying within my LT heart rate zone).

So now what?
I gave these results to my coach and I am going to see what he recommends. I am also meeting with a sports physiologist to go through these results in more detail and see what ideas she has on nutrition and specific training must-haves. I have six months until my next marathon attempt, so that should be plenty of time to get  my endurance back to where it needs to be. It's exciting in a way because now I know I have a lot of room to improve.

I'm also working with a sports psychologist on the performance anxiety issue. Even those this test was helpful, it does not explain why I am exhausted at mile 8 of a marathon, but I have no problems with long runs.


  1. You know, I did this once, but I'm very curious about what a "check-up" would look like. So interesting to see how you have changed!

  2. Interesting, and also interesting to see what coach's reaction is.

    I have to admit, I've decided not to take a VO Max test, just because there's no positives from taking one. Either you hear that your potential is limited, and you get depressed, or you hear that you're underachieving, and you get depressed. And you also start staring at your HRM, instead of relying on feel. Just my hunch.

    I'm REALLY glad you're moving forward with the sports psychology. Very worth the money and time -- give it a chance to work.

  3. Cris- I totally see your point. I left there feeling discouraged. And even before I knew my new zones, I could tell that anything above 162 was not "easy" so I know I am a decent judge of running based on feel.

    The sports psychologist is excellent. I've been to psychologists in the past who just sit there and listen and don't give you stuff to work on. This guy is actually working with me on things and my perspective is starting to shift.

  4. Look at your new data just as that- data, numbers. I've never had a test, but I would really like to one day. I'm also very curious to see how your coach interprets this data and what he does with it (if anything). Have you found a sports psych? I know a good one...

  5. I have thought about doing this...but I don't know what I would do with the info and I think I would stress over it more than anything.

    I never did over a 4 mile tempo this past training cycle because I just felt like those were tough enough. We always have CAR people out there doing 5 mile and 10k tempos though! You won't be alone.

    Good luck in this journey and don't forget...this is supposed to be fun. Make sure you don't lose sight of that.

  6. I love having the *data* of knowing HR ranges, but I don't think it really means anything. You are best suited to what you are training for, not what a monitor says. I look at the data after runs, but never base my runs on HR alone. Good luck!!

  7. I don't know what I would do with the numbers, but I do think it would be interesting to do a VO Max test to see where I stand. To be honest, I think it might be most helpful to me to make sure that all of my recovery runs are done properly, more than it would be for harder workouts.

  8. Wow that's really neat that you're going through all this extra stuff for training! Interesting stuff too. I think I don't even want to know what my VO2max is! :)