Coach and exercise physiologist Dr Mike T. Nelson pulled me to one side recently after seeing the results of my little experiment with a ketone ester supplement. In this interview, you’ll learn about why Dr. Mike thinks we should exercise caution before regularly simultaneously raising blood glucose and ketones.

We also talk about why metabolic flexibility, not ketosis, should be the goal for most endurance athletes.

Problems with impaired fat use:

From  Nelson, Michael T., George R. Biltz, and Donald R. Dengel. "Repeatability of Respiratory Exchange Ratio Time Series Analysis." The Journal of Strength & Conditioning Research 29.9 (2015): 2550-2558.

"Goedecke et al. (12) showed a very large interindividual variability in resting RER from 0.72 up to 0.93 that even persisted during exercise of increasing intensity. This corresponded to a relative rate of fat oxidation that ranged from 23 to 93%. This large interindividual variability in RER from 0.83 to 0.95 was also demonstrated by Helge et al. (16) during low-intensity steady-state exercise. This was quite similar to what we observed with a range of RER from 0.82 to 0.97.” (Nelson, MT, et al. 2015).

Goedecke, Julia H., et al. "Determinants of the variability in respiratory exchange ratio at rest and during exercise in trained athletes." American Journal of Physiology-Endocrinology And Metabolism 279.6 (2000): E1325-E1334.

Helge, Jørn W., et al. "Interrelationships between muscle fibre type, substrate oxidation and body fat." International journal of obesity 23.9 (1999): 986-991

Problems with impaired carb use:

Research has shown that those are on a very low carb diet for prolonged periods of time demonstrate a reduced ability to fully use them during exercise (Burke, LM, et al.; Stellingwerf T. et al).

Burke, Louise M., et al. "Effect of fat adaptation and carbohydrate restoration on metabolism and performance during prolonged cycling." Journal of Applied Physiology 89.6 (2000): 2413-2421.

Stellingwerff, Trent, et al. "Decreased PDH activation and glycogenolysis during exercise following fat adaptation with carbohydrate restoration." American Journal of Physiology-Endocrinology and Metabolism 290.2 (2006): E380-E388.

Finally, we discuss the potential interference effect of endurance exercise on strength training. Context matters! Only elite athletes probably need to worry about this, and at least one study has shown untrained women can use either order and get similar responses.

Here’s the outline of this interview with Mike T. Nelson, PhD:

[00:01:02] Keto Summit interview on Metabolic Flexibility.

[00:03:25] Complete Blueprint To Faster Results...Without Pain and Plateaus.

[00:06:14] Get the "Deadlift Re-alignment for Broken Meatheads." for free.

[00:07:28] Online coaching.

[00:08:58] http://www.miketnelson.com/podcast

[00:09:15] HRV for Successful Online Coaching with Dr. Mike T. Nelson.

[00:09:38] ithlete.

[00:12:29] Zoom video conference software.

[00:13:08] Instant Ketosis: 0.4 to 6.2mM in 30 Minutes.

[00:13:47] Dominic D'Agostino: Researcher and Athlete on the Benefits of a Ketogenic Diet.

[00:15:34] Cox, Pete J., et al. "Nutritional ketosis alters fuel preference and thereby endurance performance in athletes." Cell Metabolism 24.2 (2016): 256-268.

[00:16:57] Ketone esters for endurance performance.

[00:20:05] Ride time to exhaustion.

[00:21:04] Professor Kieran Clarke at Oxford University.

[00:22:27] Why You Should Skip Oxaloacetate Supplementation, Fueling for Your Activity and More!

[00:25:19] Brooks, George A., and Jacques Mercier. "Balance of carbohydrate and lipid utilization during exercise: the" crossover" concept." Journal of applied physiology 76.6 (1994): 2253-2261.

[00:26:10] Ketone salts and C8 (caprylic) oil to "push the process".

[00:28:05] Fasting and carbohydrate adaptation.

[00:28:18] Pyruvate dehydrogenase (PDH).

[00:29:39] Ketone supplements and appetite suppression.

[00:33:36] Jeff Rothschild.

[00:34:20] FATMAX and the hard transition.

[00:35:18] Peterson, Benjamin James. Repeated Sprint Ability: The Influence of Aerobic Capacity on Energy Pathway Response and Fatigue of Hockey Players. Diss. UNIVERSITY OF MINNESOTA, 2014.

[00:37:42] Reintroducing carbs.

[00:41:43] Sprints on wet tarmac (not recommended).

[00:43:07] Terzis, Gerasimos, et al. "Early phase interference between low-intensity running and power training in moderately trained females." European journal of applied physiology 116.5 (2016): 1063-1073. Coffey, Vernon G., and John A. Hawley. "Concurrent exercise training: do opposites distract?." The Journal of physiology (2016). Also, 5-10x 2 minute intervals at 120-150% of LT (HIIT) and 15-30 minute continuous cycling at 80-100% of LT equally interfere with the adaptations to resistance training. So it’s not the intensity, more the total volume, that’s the problem.

[00:46:22] Prioritising strength in the offseason.

[00:48:40] Kiteboarding.

[00:49:55] Fortaleza.

[00:51:06] Mike's email.