VO2 Peak

It’s been A LONG time since my last post.  I’ve wanted this to be my “next post” since our sister-trip to Canyon Ranch.  Although I have had other experiences and topic ideas since then, I promised myself I wouldn’t post anything else until I did this one the justice it deserved.

When I started this blog I committed to you, and myself, that I wouldn’t let it become just one of those “online diaries” where after reading a post you think to yourself “Oh I totally feel you, girlfriend!” or “Wow – she’s kind of whiny.” 🙂  I wanted you to learn something, to take something, no matter how small, and have it change the way you act or think down the road.

After what’s admittedly been a lot of “diary” posts over the last year – I had baby brain so cut me some slack! – I’m ready to share some fun stuff!

This topic doesn’t require a PhD in biology, however, it’s a term that often just becomes part of the runner vernacular and we don’t necessarily understand what it really means.  As I mentioned in my previous post about Canyon Ranch, the team of physicians and physiologists are pretty spectacular and I would recommend meeting with one of them before you schedule that massage.  The physiologist I met with for my VO2 max test was really good at explaining it all in laymen terms, so I’m going to try and share it the same way with all of you…

What are we trying to learn?  VO2 max is the maximum amount of oxygen that an individual can utilize during intense, or max exercise effort. It is measured as milliliters of oxygen used in one minute per kilogram of body weight.  Broken down another way, it’s basically an efficiency measure.  How much oxygen does your body use to produce the energy needed to work at your peak level?

All in, the “test” takes about 20 minutes.  You’ll be on a bike or treadmill depending on your preference – I was on a treadmill.  You’ll get an “awesome” mask strapped to your face.  Note that the mask kind of obstructed my peripheral vision so I had a slight (and I mean BIG) fear that I was going to step on the dreaded front of the treadmill the whole time and smash my face into the screen, so just a heads-up on that.  You’ll also have a heart rate monitor strapped across your chest.

The mask is measuring the amount of Oxygen you are inhaling in ml per minute and the amount of CO2 you are exhaling in ml per minute.  During the 20 minutes, the physiologist or physician, will continue to increase the speed and incline at which you are working until you hit what YOU determine as your max effort.

When the test is done you’ll have learned more than just your VO2 max.  All the results are given relative to the World Health Organization’s “predictions” based on your gender, age, height and weight.  Although the numbers below are specific to me, I’m hoping the accompanying explanations give you some pause when thinking about your own workouts and how your body is an absolute MIRACLE machine you should give the ultimate respect to.

  • Heart Rate Ranges:
    • Steady Effort: 150 bpm equated to about a 10:00 min mile
    • Interval Peak: 170 bpm equated to about an 8:30 min mile
  • Lean Muscle: 130 lbs (Okay I didn’t learn this from this test, but I’d done a body comp test the day before so we were able to use those results in conjunction with the calorie information).
  • Energy Expenditure i.e. Calorie Burn
    • My Average = 13.5 kcal
    • Thanks to my “Susan time”, I have a slightly higher calorie burn at rest than the “average bear”.  Yeah for muscle tone!  Based on this info, it explained why the “normal” 1,200 calorie “diet” always left me REALLY HUNGRY!  Based on these results, 1,800 is a better target on days that I exercise and 1,600 on rest days.   Once I’ve hit my target weight, 1,800 on rest days and 2,000 on exercise days should be my benchmark.  How did we get there?
      • 130 lbs lean muscle x 13.5 kcal/day = 1,755 calories burned at rest
      • Assume a 600 calorie burn on a 45 minute run = 2,355 calories burned in the day
      • 1 lb fat = 3,500 calories → 3,500/7 days = 500 calorie deficit each day to lose the 1 lb in a week
      • 2,355 – 500 = 1,855 Target Calorie Consumption on Exercise days
  • VO2 ml/min = Oxygen In
    • My Peak = 3,356 which compared to the WHO predictor of just 2,110
  • VO2 Max: The “Fitness” measurement
    • My Peak = 41.5/kg/ml/min/kg which compared to the WHO predictor of 35.05
    • You can also use your VO2 max to determine your “fitness age”.  In my case, my VO2 max put me in the 75th percentile of the 25 – 29 y/o WOOT WOOT! #fitmama
  • R-Value: Ratio of CO2 produced to Oxygen utilized
    • As this number approaches 1.0, you are getting more anaerobic (introducing glycogen as energy supplement)
    • My R-Value was 0.89 at my “peak effort” which was 8:30 min/mile at 1.5% incline
  • Heart Rate:
    • My heart rate at max effort was 168 vs. the WHO predictor of 185
  • VO2/HR (ml/bpm):  How much Oxygen is pumped per beat or “The Power of your Heart”
    • My Peak was 19.8 vs the WHO predictor of 11.4 or 174% of the predictor (anything over 120% is ideal – thank you strong heart!)

What’s really cool about all of these numbers is that they are “point in time”.  Even without super fancy monitors, I could do some heart-rate training tomorrow and see if at the same 168 peak heart rate, I can hold a faster speed for longer.

As I’ve mentioned before, I’m “slightly” goal oriented so it will come as no surprise that I asked the physiologist whether there was a max expectation based on your innate body make-up.  I wanted to know if the best I could ever hope for was, for example, a 20% improvement from where I was at the time.  Her response, “If you were to quit your day-job, say good-bye to your husband and kids, and commit to training, and only training, for 2 years, you MIGHT hit your limit.”  I had gone into this half wanting to determine if missing the 4 hour marathon target a couple years ago was because “my body just couldn’t do it.”  With that one sentence, and all the measures being so solid just 6 months after birthing a GIANT CHILD, I’d say my body is MORE than capable.  For a pretty mental trainer, that was just the confidence I needed to get back on the horse.  We hear it often, but our body is capable of so much more than our brain leads us to believe.

I really hope you found this interesting and took a kernel of learning with you into the rest of your day and training!

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