Wednesday, January 21, 2009

Carb Burning Machine

Apparently I am a carbohydrate-burning machine. I did the New Leaf metabolic assessment last week. As part of the assessment, they strap a mask over your mouth and nose so they can measure your input and output of oxygen and carbon dioxide. From that data, along with your heart rate, they can determine your aerobic base, anaerobic threshold, VO2 max, and your proportion of fats vs carbs used at given heart rates during a workout. Once I start running, I move fairly quickly into carb burning for energy. This isn't good for an ultra runner. I was satisfied with my VO2 max and anaerobic threshold, but my aerobic base (threshold?) where I burn 50/50 fats and carbs was way too low. With a strong emphasis on easy aerobic runs over the next 12 weeks, I should be able to move that aerobic base to a higher heart rate. The closer it gets to my anaerobic threshold, the happier I'll be. If possible, I'd like to redo the assessment in about 12 weeks.

I strongly encourage anyone that has access to this type of test to try it out. On the New Leaf Fitness web page they have a search for local certified sites. There were two in the Champaign, IL area: Nutrition at Work and the University of Illinois Activities & Recreation Center. The cost for the test is not cheap, but you may find it useful and worthwhile. I paid $80 at the University's recreation center (available to students and campus recreation members). Nutrition at Work charges about $225 (their assessment is a bit more thorough and includes some follow-up visits).

So what am I changing based on this assessment? Time to adjust (yet again) my Maffetone heart rate zones. Just a couple weeks ago, I decided to INCREASE my HR zones, now I am DECREASING them below their original values. Hey, data don't lie! My aerobic base needs to be bigger, better, and badder. My new zones are based on Phil Maffetone's unadjusted formula of 180-age (180-42=138) as the top aerobic heart rate. Combining Maffetone & Mittleman, I get 3 training zones:

MAP: 108-128
MEP: 128-138 <== 138 is top aerobic HR
SAP: 138-158

I have two related blog posts about this Maffetone heart rate setting process. One on January 13, 2009 and another on July 17, 2008. Check 'em out if you want more details. I am dedicated to building my aerobic base over the next 3 months. After the McNaughton Park 100 miler (April 10-12), I'll review my training and see where to adjust. Maybe I can do another New Leaf metabolic assessment before April 10...that might give me extra confidence going into the 100 miler.

I hope to be an aerobic monster by this summer!

Watch out at races later this year...I'll be the tall, skinny guy with huge lungs and a low heart rate that silently zooms past you as you enter into oxygen debt...and that's a debt you don't want to pay.

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