AIR DATE: January 31, 2013 at 7PM ET
FEATURED EXPERT: Ben Greenfield
FEATURED TOPIC: “Ketogenic Diets And Exercise Performance”
Carbohydrate loading has become so deeply-ingrained (all pun intended!) in our culture for endurance athletics these days that hardly anyone questions whether it is the most effective means for fueling exercise performance or not. But ketogenic diet researchers like Dr. Stephen Phinney and self-experimenters like Dr. Peter Attia have discovered a new paradigm that could quite possibly be the future of fueling exercise activity–using ketones as an alternative and much more preferred energy source for fueling exercise. And we’re pleased to have a bona fide expert on this topic with a triathlete and sports scientist named Ben Greenfield (listen to my interviews with Ben in Episode 609 and Episode 457 of “The Livin’ La Vida Low-Carb Show” podcast) who is joining us in Episode 37 of “Ask The Low-Carb Experts” to share what he has learned about the role ketogenic diets can have in maximizing exercise performance.
Do you think a ketogenic nutrition plan is compatible with training at lactate threshold? And for races shorter than 5000 meters, is a ketogenic diet optimal or detrimental to maximum performance?
I’m interested in whether you’ve come across research or anecdotal evidence of the effects of a ketogenic diet on exercise performance in women? A lot of the research that has been conducted seems to be in men. I am an endurance runner and I am much better doing longer distances. When I had an RER test done in a fasted state (albeit on a cycle and not a treadmill), it showed I was a complete sugar burner. However, I have no problems training (and performing) for extended periods of time in a fasted state, or with the intake of minimal to no fuel.
As far as body composition goes, I’m very lean. Would this have any effect on the RER test results? My diet composition was at the time around evenly split between the three macronutrients. But since becoming interested in and converting to the low-carb, whole food diet approach thanks to Mark Sisson, Robb Wolf and other people in this field, my CHO sources now come from fruit, a small amount of kumara/potato, nuts and non starchy greens. I used to consume a lot of grains and sugary foods. I’ve dropped all artificial sweeteners and processed foods from my diet, upped my intake of fat and feel great.
Could the small amount of sugars along with the intake of artificial sweeteners in my diet have influenced my sugar burner result from the RER test? Does it even matter that the RER test suggested I wasn’t a fat burner if I am good at running over longer periods of time with little intake of fuel as aforementioned?
If muscles draw energy from the sarcoplasm that stores glycogen for energy, then what positive effect could a low-carb diet possibly have on the sarcoplasm? I’m especially interested in bodybuilding where most studies show that sarcoplasmic hypertrophy is the key to developing larger muscles and differentiates the bodybuilder’s physiology from the power lifter.
I’m in my mid-50’s and started low-carb 2 years ago after suspecting my body wasn’t utilizing fat for energy. Twice, I did an ironman triathlon and twice, I got rhabdomyolysis. I would like to consider an endurance event again, but wonder if there’s a way to confirm my body is using stored body fat instead of protein? How can I be sure that it does? In the Fall 2012, I did a ketogenic diet for three months but wasn’t able to get my ketones higher than low 2′s.
Can you please address a ketogenic diet in relation to endurance for people who are ectomorphs? What is different, if anything, about the details of a ketogenic regimen for people like myself? I’m 6’1″ and weigh 153 pounds and I run 3-4 times a week, do yoga and lift weights on the other days.
I recently read a series of articles in which Robb Wolf makes it sound like ketosis isn’t something someone can do if they are involved in an MMA/Crossfit or other extreme intensity type work because they are too glycolytically demanding. I would love to hear your thoughts on.
I do fasted long runs of 24 miles almost every week and eat what I think is a ketogenic diet. I DO include a lot of vegetables in my diet like kale, spinach, broccoli, string beans and the like. However, I’m not seeing any ketones in my urine Ketostix. Are these reliable? Could you talk about high-end athletic performance and the ketogenic diet. I run anywhere from 5Ks to 100Ks. Am I likely to see slower times in the shorter races and better times in the longer ones? And are you aware of any pro runners out there using ketogenic diets?
Would you recommend going into ketosis while training 20 hours a week for an ironman race?
GEZ FROM THE UK ASKS:
Is it possible to exercise intensively with high performance on a ketogenic diet and at the same time maximize muscle gain and fat loss? Does it matter if the ketosis is from being low-carb or from intermittent fasting?
I am a 45-year old mom who has been low-carbing since June 2012. I am working hard on getting into full-on nutritional ketosis with readings of 1.5 in the afternoon. My goal is to get above 2.0 millimolar in the morning! I am hoping a formal weight lifting program will help me get there. After reading Ben’s Get-Fit Guy’s Guide To Achieving Your Ideal Body Weight, I realized that I am a pure Mesomorph. Here is my question for Ben: In your book, you recommend lighter weights, with more repetitions for me; however, I am intrigued by Fred Hahn’s Slow Burn and his suggestion to use weights heavy enough for complete muscle fatigue with just a few reps. Is your suggestion for the lighter weights for cosmetic reasons? As a Mesomorph, can I actually get as strong and build as much bone density when lifting lighter weights, with more reps, as I can with lifting heavier weights in the manner Hahn suggests?