The Great Aerobic Ketogenic Experiment: Week One

I’ve been eating a low carb high fat (LCHF) diet for nearly 4 years now. I’ve used ketosis on and off durning this time. I’ve also been using the principals of Maximum Aerobic Function (MAF) for some years now as well. The two principals work hand and hand, but I’ve not seen the results I’ve been desiring. Sure I’ve made progress, but I’ve heard more dramatic results coming from people who use these methods. Recently, I started reading, ‘Primal Endurance’ and it finally clicked for me.

IMG_5027While I had been following a LCHF approach along with MAF training, I was also lifting, a very anaerobic activity. This goes against the aerobic base period principals. ‘Primal Endurance’ also outlined a very easy to understand periodization plan that I decided to put into effect.

In an effort to really track how this all works, I will be measuring results and charting them. This way I’ll visually be able to track the changes to ensure I’m seeing the correct trends. I’ve decided to provide weekly updates so you can view the progress as well. It will be very interesting to see just how a purely aerobic training period, in conjunction with a nutritional ketosis diet will effect athletic performance and overall health.

I’ll be tracking the following metrics with the corresponding equipment:

  • Weight – Withings Scale
  • Ketones – Ketonix
  • Blood Glucose – Precision Xtra
  • HRV – SweatBeat App
  • Resting HR – Withings Aura
  • Sleep – Withings Aura
  • MAF Run Pace – Garmin Fenix 3
  • Calories In – Calories consumed for the day
  • Calories Out – Active calories burned tracked by Apple Watch and exercise
  • Percent Fat
  • Percent Protein
  • Percent Carbs

We can follow these changes to see how they are effecting performance based on the MAF pace. In a nutshell, MAF follows the 180 formula, take your age and subtract it from 180. The result is the maximum heart rate you can train at. It needs to stay within 10 beats under that number as well. The idea is you build aerobic endurance, and perform faster feats at the same lower heart rate. While I’ll be using my running pace to calculate improvements, I’ll also be tracking cycling and swimming. I fully intend to keep track of progress with these as well, but I think the running pace will provide a more consistent result.

Many athletes have seen incredible results from this type of training. This concept is not new at all, but I want to put it to the test. I’m going to put this methodology to use for my entire 2016 season. I’ve use the principals of an aerobic base period and and intensity period to structure my season. I plan to adhere to this pattern as strictly as possible, but will share anything that might effect the results.

With that outlined, lets take a look at how the first week went:


The training plan for the week one was; Monday swim 2500 yards, Tuesday Run 90 minutes, Wednesday Bike 90 minutes, Thursday brick run/bike 1 hour each, Friday swim 2500 yards, Saturday run 2 hours, Sunday bike 3 hours and swim clinic.

All workouts were competed as planed. Overall it was a good week of training, but my run on Saturday was probably the worst I’ve had all year. I had been looking forward to Ride the Rockies this year, and Friday night I got the email that I wasn’t selected. So I’ll not be able to participate. This was quite a blow as I had planned in participating every year. Also I was really looking forward to the route this year. I had also not signed up for the Boulder 70.3 because it was the day before Ride the Rockies, and now I could have done that race. Anyway, I was bummed and I had a very hard time keeping my heart rate in MAF. Because of this my pace suffered greatly.

I also realized it’s near impossible to get out and ride the bike at MAF here in Colorado. Avoiding hills is not practical and even trying to get up then at MAF is a near impossibility for me right now. This is going to present some challenges as I move forward. Also the bike ride was only 2 hours instead of three as planed.

MAF Run Pace

MAF Run Pace Progress

Average Macronutrient Intake

Average Macronutrient Intake


I did okay with my diet, however my carb intake was higher than I wanted it to be. Over the weekend I did use UCAN SuperStarch, which has a high carb content, but will keep me in ketosis. So there are some inflated carb numbers due to that. What was interesting is my ketones actually went up when these carbs were added. While that’s entirely the point of UCAN, it’s an interesting observation. I’m very curious to see how my ketones will respond over the week with just carb restriction. Most of my week night workouts are not long enough to require SuperStarch.

While I don’t really feel that calories are an important metric, I want to experiment how they effect other things. Also I think it’s important to get a clear picture of how much food is actually being consumed. The calories in number is fairly accurate as I track what I eat. There is some room from error of course. Calories out measures only active calories as traced by the Apple Watch and/or Garmin. For example the Apple watch doesn’t count swimming activity so I add the Garmin measurement to that for a total number.


Weight vs. Calories in and Out


I’ve been measuring my glucose and ketones in the morning, fasted. The big observation that I’ve noticed is that my ketone levels are relatively low in the mornings. The rough scale for nutritional ketosis using the Ketonix is a reading between 40 and 70. It seems that I’ve been falling a little short of this range in the mornings. I do test in the afternoons as well, and my levels are up significantly. Although it appears this is normal when measuring breath ketones. Because of this I’ll be including all my ketonic data in a separate chart. I’ll also track blood glucose to see how those numbers correspond.


Breath Ketones vs. Blood Glucose

Since it’s only been a week there is not a lot that has been discovered so far. There are no clear trends, where we can draw conclusions from just yet. It will be very interesting to see how this shapes up though.


Overal Markers


Growing up in Colorado you can't help but love the outdoors. Something magical happens with 300 days of sunshine and the Rocky Mountains in your back yard. My athletic endeavors started on the bike, I would get out and ride whenever I could. In 2011 I moved to Oxford, England for work. I missed the sunshine and mountains, but discovered my passion for running. When I moved back to Colorado I started combining cycling and running, so it was only natural that I started competing in triathlons. I took second place at my first sprint, and caught the bug. Today I'm training for my fourth Ironman.

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