"she's on the fat side of things" - FUEL/Lactate/V02 test

I overheard this comment about me...
Craig H. - "If you had to guess...how is she looking?"
Rob P. "I'd say she's on the fat side of things"

This was my coach, Craig asking Rob (Exercise Physiologist @ BSCM) about my fuel burn capacity.   I've been working on becoming a more efficient fat burner and now was the moment of truth.  Either I had done the work or not - the machine they had me hooked up to would provide data - cold hard facts.

FUEL test results:

For the past 3 months I've been doing the following:
1. Ran most of my miles at an embarrassingly slow pace (seriously, just look at my DM stats!)
2. Ran my long runs without any fuel - only water.
3. I changed my diet to be higher in fat.  45% fat, 20% protein, 35% carbs (no processed carbs - except the occasional pancake). 

Here are the results:

• Zone 1 & 2 - ~50% fat burn - 50% carb burn
• Zone 3 -       ~42% fat burn - 58% carb burn
• Zone 4 -       ~36% fat burn - 64% carb burn
• Zone 5 -       ~26% fat burn - 74% carb burn

I just emailed my coach the info - but according to the BSCM nutritionist I met with tonight - she said the fact that I am still burning 26% fat when I'm hitting that anaerobic zone is outstanding.  She said many people are at 100% carb burn in this zone.

Based on this information my coach will draft a marathon fueling plan and starting with this week's 18.5 mile run.

With my layman's knowledge - I'm guessing he'll have me run at ~160-162 HR for marathon pace.   As a guess - I'm thinking I can store ~1200 grams of carb (I'm 4'10") so at a 418 carb burn per hour that will last me 3 hours.  Well i KNOW I won't be running a 3 hour marathon - so I'll need to fuel with at least 400-600 calories in order to avoid bonk mode.   But I'll wait to hear from him on specifics.

I'm stoked to have this data to help formulate a (hopefully a smart) marathon fueling plan.

And the question remains - will my body tolerate and be able to process 400-600 calories while running marathon pace??

Lactate - red line on chart above

Rob said that typically when people hit LT that red line jumps dramatically - since mine wasn't a super big jump that means I have more of an endurance physiology.  He said "You'll never win a 5k."   :(

Coach Craig wanted this data to verify my zones were correct.   They were a little off - but close.   One of the big discrepancy was Zone 1.  I've been running a lot of my Zone 2 runs at 145/146 HR and it turns out that's the top end of zone 1.  whoopsie.    But I don't mind, that means I can now run a little faster to be in zone 2.

And to see what the last 41 seconds of a 5.5 minute V02 max test looks like - check out this video.  You can hear me groaning in pain at the end.




Yeah - I have no idea why I am smiling in this picture...they are sticking my finger to get blood.