Getting Van Wilder to Boston

The Big Question Remains

How to best fuel Van Wilder’s (Another VO2max Test – Van Wilder) next marathon? It is six weeks away and he’s not far from qualifying for the Boston Marathon. Is it best to shift to a high carb low fat diet for the marathon?

Pace vs Heart Rate Test

We did a test of pace vs heart rate.  The test was done on a track in 800 meter distance increments with speed matched to 10 bpm heart rate steps every 2 laps (of the 400 meter track). We downloaded the average data from the logging application.

We then overlaid the pace vs heart rate data with fat-carb oxidation rates from Van Wilder’s VO2max test. Here’s the resulting curves:

The top curve is running pace. Van Wilder’s fastest pace was almost a 4 minute mile. At that rate, he was have been oxidizing around 22 calories of carbs and 9 calories of fat per minute. The rate is also not sustainable due to the high exertion required.

Van Wilder has to run the marathon in about 3 hours. That’s 26.2 miles/3 hrs = 8.7 mph. That’s 60 min/hr divided by 8.7 miles/hr = 6.9 minutes per mile. That’s a heart rate of 155. That is also around 15 calories per minute from carbs and 12 calories per minute from fat. 15 kCal/min * 60 mins = 900 kCal/hr. If he can feed 360 kCal/hr from carbs that’s a net of 540 lost per hour. In three hours his muscle glycogen will be completely gone (assuming it can all be used).

Probably can’t get there from here – at least at the current performance.

Update 2018-09-14

Van Wilder suffered a hip injury and had to drop out of his qualifying marathon last week. That was the last chance for the season.


Athlete Van Wilder – Part 2

In an earlier post, I took a look at Van Wilder (Another VO2max Test – Van Wilder). He was a low carb guy but has bumped up the carbs. quite a bit. The day before the VO2max he ate quite a few carbs.

Let’s look close to see if our VO2max curves are comparable to the Volek FASTER chart. Here’s the FASTER chart:

The HCD (High Carbohydrate Diet) looks like an inverted parabola and can be modeled as a 2^X function. Due to the distorted hump, the LCD (Low Carbohydrate Diet) looks like a higher order polynomial (more than a square = 2nd order). Assuming a 3rd order polynomial would model the curve better. Revisiting the VO2max data for Van Wilder (as a third order polynomial):

Here is my VO2max data (also as a third order polynomial):

My curve looks more shifted to the right similar to the FASTER graph. Both of the graphs have the same 50%-50% calories point at about 80% of VO2max.

Van Wilder’s MFBGS (Maximum Fat Burning Glucose Sparing) point is at around 43% of his VO2max. My own MFBGS is quite a bit higher at around 61% of my VO2max. Does that provide any real advantage? Certainly my 20+ years older doesn’t help me out.

Van Wilder’s MAF Number

Van Wilder is a well trained athlete but he’s constantly injured. He should have a reduced MAF number but let’s assume he’s at the 180 – 35 = 145 heart rate.

Van Wilder’s MFBGS point is at around 118 bpm. At his MAF number he’s well into carbohydrate burning (around 65% fat and 35% carbs).


Train Low, Compete High

One popular Low Carb strategy is to train low and compete high. The basic strategy is to do all training in a fat adapted state and then switch to a higher carb state a day or two before competition.  A study took a look at this methodology (Havemann L, West SJ, Goedecke JH, Macdonald IA, St Clair Gibson A, Noakes TD, Lambert EV. Fat adaptation followed by carbohydrate loading compromises high-intensity sprint performance. J Appl Physiol 2006 Jan;100(1):194-202.). The study consisted of six days of High Fat diet to a High Carb diet on the 7th day. The study looked at the performance on the 8th day. The purpose of the carb fueling was to fill glycogen stores before the final tests.

The ingestion of a HFD for 6 days resulted in a shift in substrate metabolism toward a greater reliance on fat and a reduction in CHO oxidation. The increase in fat oxidation in the present study persisted despite 1 day of CHO loading on day 7 as demonstrated by the lower resting RER (0.77  0.02 vs. 0.88  0.05, Fig. 2) and higher circulating FFA (Table 7) during exercise after HFD-CHO compared with HCD-CHO on day 8.

Here’s what was valuable about this 2006 study.

The study is unique in that it is the first study to investigate the effect of high-fat feeding, followed by CHO loading, on endurance exercise, including high-intensity sprints that simulate actual race situations.

In spite of being on a High Carb diet the effects of the High Fat diet persisted. This could be seen in a lower RER value indicating increased fat oxidation. However, the sprint performance was not as good. From the discussion:

It was hypothesized that the potential glycogen-sparing effect of this dietary strategy (3) would be most beneficial for exercise that included high-intensity sprint bouts, where muscle glycogen is the predominant fuel. However, in contrast to our hypothesis, the HFD-CHO strategy actually compromised high-intensity 1-km sprint performance.


Study of Glycogen and Exercise Studies

Thanks to Luis at Ketogains for pointing to a great study which looks at the studies of Glycogen and Exercise (Pim Knuiman, Maria T. E. Hopman, and Marco Mensink. Glycogen availability and skeletal muscle adaptations with endurance and resistance exercise. Nutr Metab (Lond). 2015; 12: 59.).

…Recent research into the effects of glycogen availability sheds new light on the role of the widely accepted energy source for adenosine triphosphate (ATP) resynthesis during endurance exercise.

Indeed, several studies showed that endurance training with low glycogen availability leads to similar and sometimes even better adaptations and performance compared to performing endurance training sessions with replenished glycogen stores.

The study leads with:

…Glycogen is made and stored in cells of the liver (~100 g) and muscles (~350 – 700 g; depending on training status, diet, muscle fibre type composition, sex and bodyweight) and can be reduced by fasting, low intake of dietary carbohydrates and/or by exercise.

Intermittent Fasting, Low Carbs, exercise. Yep, that’s me.

Glycogen is differently distributed within the muscle fibers (subsarcolemmal ~5-15 %, intermyofibrillar ~75 % and intramyofibrillar ~5-15 %)

And here’s the bit about high intensity workouts:

Glycogen is an essential substrate during high intensity exercise by providing a mechanism by which adenosine tri phosphate (ATP) can be resynthesized from adenosine diphosphate (ADP) and phosphate.

The relative use of energy sources during exercise is mainly determined by the intensity and the duration of the exercise bout, as well as the athlete’s training status.

Fat as source of energy is relatively most dominant during moderate intensity (30-65 % of VO2peak), whereas the relative contribution of carbohydrate oxidation to total energy expenditure becomes greater when exercise intensity increases, with muscle glycogen becoming the most important substrate source

…glycogen availability is essential to power ATP resynthesis during high intensity exercise which relies heavily on glycogenolysis.

Furthermore, it has been well documented that the capability of skeletal muscle to exercise is impaired when the glycogen store is reduced to a certain level, even when there is sufficient amount of other fuels available.

To date, few studies have found an improved training-induced performance effect of conducting the exercise bouts with low glycogen levels compared with replenished glycogen levels

On the subject of resistance training:

… a typical resistance exercise session has been shown to reduce glycogen levels by approximately ~24-40 %. This reduction in glycogen content during exercise is determined by the duration, intensity and volume of the performed exercise bout. The largest reductions in glycogen are seen with high repetitions with moderate load training, an effect that mainly occurs in type II fibers.

Remember glycogen is the storage form of glucose.

Volek Talks about the FASTER Study

A video from 2015 where Dr. Volek talks about the FASTER Study (Jeff S. Volek, Daniel J. Freidenreich, Catherine Saenz, Laura J. Kunces, Brent C. Creighton, Jenna M. Bartley, Patrick M. Davitt, Colleen X. Munoz, Jeffrey M. Anderson, Carl M. Maresh, Elaine C. Lee, Mark D. Schuenke, Giselle Aerni, William J. Kraemer, Stephen D. Phinney. Metabolic characteristics of keto-adapted ultra-endurance runners. Metabolism, Volume 65, Issue 3, March 2016, Pages 100-110.).

  1. Fat adapted athletes become “bonk proof” (see my post about that).
  2. Group of ultra-runners.
  3. More athletes volunteered than could be tested.
  4. Matched groups.
  5. LCD group was 70-20-10 F-P-C.
  6. HCD group was 25-15-60 P-F-C.
  7. Day 2 was three hours at 65% of VO2max (see my post about that). He later stated it ended up being at 64% of VO2max.
  8. They thought peak fat oxidation would be lower due to other studies documenting lower rates. They could have told from any low carb VO2max test that the peak rates were higher in Low Carb dieters.
  9. It looks as if they picked the 65% number based on this study (Achten J1, Gleeson M, Jeukendrup AE. Determination of the exercise intensity that elicits maximal fat oxidation. Med Sci Sports Exerc. 2002 Jan;34(1):92-7.).
  10. Volek showed the same graph from the VESPA article with the shift up and to the right of the fat oxidation curve (see my post about that).
  11. The statistically identical glycogen levels before, after and at the end of recovery were a surprise to Volek (as they are to me). Does fat allow the glycogen stores to refill? He thinks there is a chronic adaptation in LC athletes. It isn’t likely to be peripheral insulin resistance since the athlete’s muscles were biopsied to measure the glycogen levels, right? Alaskan sled dogs may provide a clue?
  12. Athletes were on LC for an average of 19 months.
  13. Gene expression differences between the two groups still being analyzed. Glycogen metabolism gene differences.
  14. LDL Cholesterol levels were much higher in LC athletes. HDL was also much higher in LC athletes.
  15. LDL Particle distributions were better in LC athletes (fewer smaller and more large LDL).
  16. Insulin Resistance scores were much better in LC athletes (top 1% of population).
  17. Half the high carb athletes have switched to low carb diet after the study.



Another VO2max Test – Van Wilder

I’ve got another friend, call him Van Wilder, who got his VO2max tested. He’s a 35 year old triathlete who has done an Ironman and marathons. He has about five years of running training. He did the Ironman fat adapted with very few carbs during the event. He’s recently gotten off the Low Carb bandwagon, at least partly. He is still lower carb.

Van Wilder’s VO2max came in at a respectable 59.8. That puts him within 5% of the elite athletes like Zach Bitter and Ben Greenfield. Van Wilder’s max fat oxidation rate is very close to the top levels measured in FASTER  (Jeff S. Volek, Daniel J. Freidenreich, Catherine Saenz, Laura J. Kunces, Brent C. Creighton, Jenna M. Bartley, Patrick M. Davitt, Colleen X. Munoz, Jeffrey M. Anderson, Carl M. Maresh, Elaine C. Lee, Mark D. Schuenke, Giselle Aerni, William J. Kraemer, Stephen D. Phinney. Metabolic characteristics of keto-adapted ultra-endurance runners. Metabolism, Volume 65, Issue 3, March 2016, Pages 100-110.).

Here’s Van Wilder’s %VO2max vs Fat and Carbs Oxidation rates (in kcal/min).

At his peak he’s burning somewhere around 12 kCals a minute of fat. At the end Van Wilder is burning more than 22 kCals a minute of carbohydrates. His point where he’s burning 50% fat-50% carbs is at 80% of his VO2max. His peak fat oxidation is around 58% of VO2max. However, the point where he start burning carbs is relatively low at 45% of VO2max.

Compare his data with mine. I am fat adapted and only eat keto/low carb. I’m also 23 years older and not as trained by a long stretch.

Here’s the differences:

Parameter Van Wilder Doug LCS
Max Fat Oxid.
13 11
Max CHO Oxid.
22 22
Max Fat Oxid
58 53
Max CHO Oxid
100 100
50% Fat Oxid
50% CHO Oxid
80 78
Max Fat Oxid
Zero CHO Oxid
43 59

I would like to suggest that the main difference is found in the last row. My rate at which is expend no carbs and burn the most fat is at about 59% of my VO2max. Van Wilder’s point is about 43% of his VO2max.

Now my VO2max at 34.1 is significantly lower than Van Wilder’s at 59.8. And that probably explains a lot of the difference above. Van Wilder still looks to me like an efficient fat burner. Especially when compared to Damian Stoy.

Competition Fueling Strategies for Van Wilder?

What should the fueling strategy be for Van Wilder? Seems like he currently has the advantage of metabolic flexibility. He can certainly use fat for fuel at lower intensities.



Vespa has a graph on their site that shows %VO2max vs Fat oxidation in Low Carb and High Carb athletes from the FASTER study (Fat Adaptation: The Emerging Science from FASTER). Here’s the chart as it appears on the Vespa site:

I can’t find this graph in the FASTER Study paper  (Jeff S. Volek, Daniel J. Freidenreich, Catherine Saenz, Laura J. Kunces, Brent C. Creighton, Jenna M. Bartley, Patrick M. Davitt, Colleen X. Munoz, Jeffrey M. Anderson, Carl M. Maresh, Elaine C. Lee, Mark D. Schuenke, Giselle Aerni, William J. Kraemer, Stephen D. Phinney. Metabolic characteristics of keto-adapted ultra-endurance runners. Metabolism, Volume 65, Issue 3, March 2016, Pages 100-110.).

But I do have some of the VO2max data tests from two of the athletes; Ben Greenfield and Damian Stoy. And Ben was LCD and Damian was HCD. So we should be able to check the graph using their data.

Here is Ben’s curve:

Here is Damian’s curve:

Peak Values

Damian’s peak rate of fat oxidation at around 0.35 g/min was about one-third of Ben’s top rate of around 1.1 g/min. So in this regard the curves do match the relative magnitudes in the Vespa graph.

Shifted Values?

The VESPA graph for the LCD vs the HCD shows a shift to the right for the peak fat oxidation for LCD as compared with HCD. In fact, the VESPA graph shows the peak of the LCD at 70% of VO2max and shows the peak of the HCD at 50%.

This doesn’t match Ben’s data at all. Ben’s fat oxidation peak is clearly around 55% of VO2max.

There is a small shift to the left for vegan Damian Stoy. His peak is somewhere around 45%.

I want to see the other data to see if Ben is at one end of the LC data but he pretty clearly doesn’t match the %VO2max vs maximum fat oxidation rate that the VESPA graph implies.

Why Should I Care?

I care because my own data matches Ben Greenfield’s data.


There is another slow steady heart rate training called Niko Niko. Here’s a good page describing it (NIKO NIKO PACE – THE GENTLE PATH TO SUCCESS).

The formula for heart rate is different than the Maffetone MAF heart rate. Niki Niko uses:

138 minus half your age.

So for me at 58 that would be 138 – (58/2) = 109 bpm. That’s not too far below my MAF heart rate of 112-122. It it at an interesting point on myVO2max test results as well. A heart rate of 109 actually has a higher fat oxidation rate than the extrapolated curve (where the real world data veers from the idealized curve). It is certainly a good point for fat burning.

The MAF number has shifted my performance upwards in just the past three weeks. Here’s my splits from my MAF test three weeks ago compared with my MAF 5 mile this AM. I’ve had to go from walking to a little jogging and walking mixed together.

That’s a pretty good improvement – around a minute and a half.

Another VO2max Test

I have a friend, let’s call him Moe. Moe is 30 years old. Moe is not a low carb dieter. Moe has been inconsistent in his training for the past two years. Moe has recently taken up running again. Moe’s MAF number is 180 – 30 -5 = 145. Use the Heart Rate Calculator to see the numbers.

Moe took the same Vo2max test that I did at WVU Human Performance Lab. Here’s Moe’s fat/carb oxidation curves.

If Moe does MAF Heart Rate training at 135-145 is heart rate would be approaching his cross-over of fat/carbs kcals per minute. However, Moe wants to burn the maximum number of calories so he runs near his max heart rate. When he runs at a high heart rate, Moe is burning carbs and not much fat. Moe could adopt a low carb diet and run slower with the positive effect of increased fat loss and no need to burn carbohydrates.

Me vs Moe

I am 28 years older than Moe. Here’s my curve with my MAF Heart Range noted.

My max fat oxidation rate is around 11 kcal/sec. Moe’s max fat oxidation rate is around 9 kcal/sec. Moe’s max carb oxidation rate is 16 kcal/min vs my 24 kcal/min.