View Full Version : Low Carb and High Performance

Nathan Stanley
05-07-2007, 10:54 AM
I've been eating a low carb diet for a good four months now, and athletically I've performed much better than when I was eating a "normal" diet. The comment I get a lot of the time is that you can't workout or compete on a low carb diet. My experience is totally the opposite. I know the Paleo Diet for Athletes is out there, but I was wondering if there were any specific articles/resources that existed on the net that I could reference that explain this? I have found this post on the Crossfit Board which is interesting: http://www.crossfit.com/discus/messages/23/20842.html


Mike ODonnell
05-07-2007, 11:10 AM
I think it all depends on your sport....as I play ice hockey...and no way could I survive on 30g of carbs....but I also believe in carb timing the key (like in Paleo of Athletes)....use PWO for the majority of carbs to fill glycogen stores to be ready for the next competition.

Steve Shafley
05-07-2007, 11:16 AM
I've talked about this in the past.

I played an entire season of rugby while on a cyclical low carb diet.

Sun afternoon -> Friday afternoon ~20-50g of carbs daily.

Friday afternoon/night: High GI carb sources ->Moderate GI carb sources
Saturday morning -> Low GI carb sources (like sweet potatoes, brown rice, etc)
Saturday afternoon -> Rugby game then copious beer consumption and unlimited food
Sunday morning -> Decent breakfast, then low carb again.

During the week, my training looked like:

Monday: Lifting
Tueday: Practice, Running conditioning, recovery methods (whirlpool, sauna, contrast showers)
Wednesday: Lifting, light running
Thursday: Practice, Running conditioning, recovery methods
Friday: Off

My weight went from ~250 -> ~205

Conditioning was painful. I have to admit that hill sprints while carb depleted got nasty.

Your mileage may vary. This worked well for me, as I had hit some fitness marks that had eluded me for a few years.

Elliot Royce
05-07-2007, 01:11 PM
I would agree that with strength sports requiring surges of activity you're going to need carbs. Mike - I would have thought your stores would have burned up by the next competition if you just do PWO?

Mike ODonnell
05-07-2007, 01:55 PM
I would agree that with strength sports requiring surges of activity you're going to need carbs. Mike - I would have thought your stores would have burned up by the next competition if you just do PWO?

Since I only play once a week....I get pwo's from the other exercise I do too...that and usually my weekends are more "free" to induldge.....so I usually am fine between games.....but always spent the day after.....I also found that sipping a mix of gatorade and whey during the game helped.....the only time I do gatorade....as 2 hours of basically anaerobic sprinting is not going to come from internal fat stores....

Daniel Miller
05-08-2007, 08:10 AM
Not performance related, but really interesting nontheless:

Epilepsy controlled by ketogenic diet:

Robb Wolf
05-08-2007, 10:40 AM
This from the Journal of nutrition and Metabolism:

Great read and it makes the point that after fat adaptation strength and long endurance efforts are not affected on ketogenic diets, however anaerobic efforts that would typically put one in the glycolytic pathway are greatly compromised. it is interesting to note however that maximum aerobic capacity is neither enhanced nor decreased in a ketogenic diet.

Now this from the Journal of Applied Physiology:

The author makes the point that although fat is the primary fuel source for long slow events, the realities of racing dictate a need for glycogen for final kicks and things like that.

I have a few thoughts on this:
1-The more your sports or activities hang in the glycolytic pathway the more carbs you will need. One may be able to force a bit of fat adaptation in someone like a wrestler...more of their recovery after training may be fed from fat breakdown vs carbs, however if this person runs out of glycogen they are dead on the mat.

2-We can manufacture glucose from 3 sources. Gluconeogenesis from amino acids, lactate in the Cori cycle and glycerol in TAG/fat metabolism. Although the body can and does run quite well on ketones it would certainly be of survival benefit to have glycogen for brief, intense activities. Another way of putting it: if nature could have figured out another way to bridge the gap between ATP/CP and aerobic metabolism, it would have. Fro activities that are both intense and moderate in duration, carbs are essential if performance is the primary concern.

3-Ketosis, whether a consequence of strictly a low carb, higher fat diet or as a consequence of intermittent fasting, appears to confer a wide range of benefits.

4-This the interplay of performance, health and longevity IMO. What one do you want to emphasize? A nice way to balance this is intermittent fasting, likely with a CLC plan something like post WO carb feedings.

Greg Battaglia
05-08-2007, 10:52 PM
I've had a lot of experience with training on very low carb diets. My finding are rather interesting and unexplainable. I used to go really low on the carbs (<30g/day) and emphasize animal fats with major increases in energy and performance. One thing I ultimately realized was that met-con began to suffer from glycogen depletion. However, interestingly, heavy bag work did not suffer at all. I could go through 16 hours of fasting on 30g carbs or less and have amazing levels of energy and power during an intense heavy bag session. Moreover, when doing things like intermittent sprinting such as in football or basketball my energy levels were also sky high. I mainly just gave up this approach because I began to bonk on met-cons, and some other health reasons. Anybody else experience this? It seems as though there is a missing link in the research.

Craig Cooper
05-09-2007, 08:15 AM
I've done a lot of experimenting with this, and posted about it several times before. Robb's article that he posted from Nutrition & Metabolism says it all. Anytime I had successfully fat adapted, I would bonk on any metcon efforts. I've been able to successfully dial in the appropriate level of carbs to prevent that from happening, and it turns out to be about half the amount that I would be eating if I was zoning everything, with most of my carbs in the PWO window.

Robb Wolf
05-09-2007, 09:16 AM
Scotty Hagnass just shot me an email yesterday and he completed Angie in 13 min (either 13 or 15...I'm blanking on that now) after an extended period of low carb and intermittent fasting. I believe that was a PR for him.

Something to keep in mind is glycogen stores can be filled with "unconventional" means such as gluconeogenesis and some of the other sources I mentioned. If met-cons are far enough apart this is viable and like Craig said smart use of post WO nutrition may further decrease carb needs for a given situation.

Steve Shafley
05-10-2007, 05:15 AM
When we're talking about "bonking" during metcon and low carb, what are we talking about here?

I've had it two ways

The first was like a dramatic build-up of lactic acid, and I had to stop to let it clear, then I could move on.

The second felt like complete and utter substrate depletion, probably akin to the classic bonk. It felt very much like when I would perform depletion work when experimenting with Duchaine's BodyOpus diet.

Craig Cooper
05-10-2007, 06:31 AM
My experience with bonking has always been of the complete and utter substrate depletion variety. It's like I've all of a sudden gained 50lbs, and my lungs are being compressed.

The most vivid of these experiences was my complete breakdown during Fight Gone Bad. I ended up with a 247.

Mike ODonnell
05-10-2007, 11:20 AM
My idea of bonking is trying to sprint or accelerate and I have nothing....no speed and my athletic performance is hindered.....all depends on the activity as some events you may be able to sustain at a lower intensity....but for pure explosiveness and speed short term I need that fuel.....the key word being more short term than sustained.

Brad Hirakawa
05-10-2007, 04:32 PM
(Small world.. I just saw the ketogenic diet article at work, before reading this thread.)

I like Robb's idea.... if a lower carb diet does affect athletic performance but allows for better overall health, I'm okay with that. I'm okay with not being the biggest bad ass at the gym (my garage) if it will increase my chances of living a longer and healthier life.


Brad Hirakawa
05-10-2007, 04:37 PM
Robbsan... so... keeping yourself in a ketogenic state will not necessarily keep you in a glycogen depleated state?

Are metcon workouts the only way to test the idea, or is there a blood biochem test I can run at the lab? I do have access to some fancy blood-serum-plasma machines. If it requires me taking a biopsy of liver or muscle, I'll pass!

Sorry for the entry level questions, but this sort of science is new to me. We become very specialized in the lab, and this is way out of my realm.


Robb Wolf
05-14-2007, 12:50 PM

I "think" one can have muscular glycogen topped off but remain in ketosis by putting carbs into the post WO period and intermittent fasting. I think I mentioned to you a few people have noted ketones via ketostrips under this approach.