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Very interesting!

Presumably the "one hour plus" rule of thumb for sugar during and sugar/protein after the workout is the same if we're running, rather than biking?


Dear Mr. Friel

If I'm training around 20-30 hours weekly, do I need any protein or other supplements?

Thank you

Nico Thirion

thanks for the article. I agree and have spent way too much on gels and energy supplements.

Could you expand on
"Some people, especially those who eat a diet composed largely of high-glycemic-load and high-glycemic-index carbohydrates (this is mainly starch) will need more sugar than the athlete who eats a diet that is more vegetable, fruit and protein focused. I see this every winter when we test the athletes I coach. Some are obviously sugar burners while others are fat burners."

Is it possible to gear your normal eating towards an endurance diet?


Joe Friel

Nico--A lot of stuff here. Read Paleo Diet for Athletes for my answers in detail.

Joe Friel

Janez--It largely depends on your diet. If low in protein, then yes. But the best form for any nutrient is in real food, not supplements. Supplements are best used when real food is not convenient.

Joe Friel

Matt-Running, swimming, XC skiing, etc.

Steve Kent

Guilty as charged!

But a question: last year you mentioned in this space you no longer considered the 4:1 carb to protien drinks such as Accelerade as being appropriate during exercise. Matt Fitzgerald is a huge proponent of the 4:1 ratio.

Care to comment on why you have altered your previous stance?



Ian Thomson

I have been using the Paleo Diet for Athletes with great results!! I was a supplement junkie, heavily influenced by all the supplement manufacturers. But eating well, and getting the micronutrients from fruits and green leafy vegetables made a huge difference.

Mr. Friel, you have a product called Going Long that I will be purchasing it soon. If am not over-stepping my bounds, can you say a few words about it? Like how is it different from the other sports drinks out there.

Again, thank you.

Joe Friel

Ian T--I designed Going Long many years ago. I no longer promote it. If what you need is sugar during a long workout it will work well.

Joe Friel

Steve-I've read all of he research and talked to many athletes who have had bad experiences with protein in long races.

Zach Wilson

Interesting regarding the proteins. What are the adverse effects athletes have mentioned or typically have for endurance events, such as half/full ironman.

Joe Friel

Zach--Bloating and nausea.



I'm wondering what your thoughts are on training indoors and supplements.

I'm regularly traveling without a bike and am in a gym on a stationary trainer for up to 2 hours where sweat is pouring out of you due to lack of cooling.

If i use pure water for these sessions i feel zonked at the end which i believe is to dehydration.

Have you any suggestions as to what i could use to ensure that im not being a sugar junkie just to replace lost electrolytes?


Spot on Joe. You have hit the nail on the head.

Erik Bricker

I would assume a metabolic bike/run test could prove this diet change works. I took one back in Feb, it showed at what HR my body switched over from mostly fat to carb. I just started dropping carb drinks for all workouts sub 3hr. Long workouts i wait till about 3hr before taking in carbs. I hope this helps by IMC in Aug.

Joe Friel

Erik B--Pay close attention to how you feel from hour 2 to 3. If you are indeed a sugar burner (high RQ at low power/pace) then you may need to start the sugar sooner.

Joe Friel

Jason--I assume you want the electrolytes to prevent cramps? Read this - http://www.sportsscientists.com/2007/11/muscle-cramps-part-ii.html


Thank you. This is so true. When I first started training I got really hungry and used lots of gels during 20 mile runs. Now I might use one, but I don't really need to. On the bike, only if I go 3+ hours I need sugar. I do use Nuun for electrolytes, particularly when it is really hot. I think the body adjusts. I kept feeling I am doing something wrong for not eating more during workouts, so thanks for this post


Hi Joe

I hope you don't mind, but I have a question about the missed workout post. I came down with a slight sinus infection a few weeks ago and I've been feeling tired ever since. What would you recommend to get back to 100%? Stay off the bike entirely for a few days? Or should I do some endurance rides until I feel better again?


Joe Friel

Ethan--It's probably ok to do some light training. The bigger issue is why you are taking so long to recover from a "slight" infection weeks ago. I hope you've seen your doc. I had this happen in 1994 and it turned out to be a coxsackie that had settled into my heart.

central park bike tours

Great post! You might find evolutionary fitness by Dr. Devany for really interesting.

J Murphy

Can you train your body to switch from a sugar burner to more of a fat burner.


Is it genetic to burn sugar over fat, or is it possible to diet and exercise to train the body to burn fat over sugar?

Joe Friel

niceswing59--At the start of exercise the body uses carb/muscle glycogen preferentially and gradually increases its reliance on fat (this does not consider creatine phosphate but don't want to make this too complex). As your aerobic fitness improves this 'switchover' to fat happens sooner.

Joe Friel

JMurphy--See reply to niceswing59.

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