Our topic this week is Part 2 on "No Guessing". We continue our interview Dr. Inigo San Milan of CU Sports Medicine and Performance Center. I mentioned some of the topics we are going to hit last week. If you missed it, you are going to hear Inigo's definitions of each training zone. You will learn what muscle types map to which zone, understand the relationship between metabolic rates and sources and muscle fiber types and zones. It's going to be a science lesson hootinany!
Thanks to last week's guests, professional triathlete's Tim Don, James Hadley and Rachel Joyce. Can't wait to see Tim and Rachel at Kona this year!
Taking the No Guessing topic with Inigo to the next level. I have some training zone definitions straight from Inigo, plus I have taken my metabolic report results and done a comparison to a generic online race nutrition calculator. I want to illustrate how different MY and perhaps YOUR individual results might be to generic calculators.
Plus, we have the final results in from USAT Collegiate Nationals. I want to share the rankings and some results, plus give a couple of special "shout outs" to some individuals and teams.
Shout Outs to:
Dr. San Millán is an Assistant Professor at the University of Colorado School of Medicine and the Director of the Sports Performance Program at the CU Sports Medicine and Performance Center in Boulder, Colorado.
Listen closely to the concepts that we discuss. After the interview, I’m going to share my actual data and drive home the point that relying on assumptions, generic calculators for training zones, caloric expenditure, etc. can be highly risky.
Inigo's Training Zone Definitions
-Z1 is recovery
-Z2 is the exercise intensity where you achieve the maximal fat oxidation rate (FATmax) which also coincides with the first lactate inflection point. This is indicative of maximal Type 1 muscle fiber recruitment before Type IIa starts kicking in.
-Z3 is when type IIa muscle fibers kick in and there is a sharp decrease in Fat oxidation and increase in CHO oxidation. The Cross-over point usually happens here. Also there is a continuous rise in lactate accumulation.
-Z4 is the exercise intensity at which Fat oxidation completely disappears and CHO is the only fuel available. Furthermore, this also coincides with a 2nd lactate inflection point (“Lactate threshold”). This metabolic state denotes maximal Type IIa muscle fiber recruitment before Type IIb fibers kick in.
-Z5 is usually your VO2max, or maximal effort you can sustain and starting to incur in anaerobic metabolism. This intensity can only be sustained for ~2-3 minutes.
-Z6 is your anaerobic metabolism and dependable on ATP stores as glycolysis is not fast enough to supply ATP for the muscles. Usually sprinting intensity.
Examples of Nutrition Calculations (Assumption v Reality)
Do you know how many calories you are burning per hour?
Me - TrainingPeaks: 590/hr at z1 - No indication of what % comes from fat
Generic Calculator: 519/hr at z1 (67% from fat)
Actual Test: 770/hr at z1 (26% from fat)
If I used a generic calculator I might assume I'm only burning 171 calories of glycogen/hour. In reality, I'm using 570. An error of 330%.
Me - TrainingPeaks: 797
Generic Calculator: 774 (28% from fat)
Actual Test: 979 (7.7% from fat)
Generic calculator says I'm using 557 calories of glycogen/hour. In reality I'm using 904.
Our show is also supported by 303 Endurance Network, which includes 303Triathlon and 303 Cycling, which covers the endurance culture, news and events on triathlon and cycling. Be sure to subscribe to the 303Radio podcast for great interviews.
Good luck to my colleagues at 303 Endurance Network who are racing at Wildflower tomorrow - Khem Suthiwan, Dana Willett and Allison Freeman. Good luck ladies!
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Thanks again for listening to MHE. Train well this week. Stay tuned, stay informed, and enjoy the endurance journey!