Carbohydrate depletion diet for endurance athletes

A carbohydrate depletion diet for endurance athletes was once popular among distance runners.

British distance runner Ron Hill was one of the first to attempt the carbohydrate depletion/loading diet. He used it in preparation for the marathon in the 1969 European Championship Marathon in Athens.

Although he was well behind as he began the final 6 miles of the 26.2-mile marathon, he eventually won the race easily. The diet did exactly what it was supposed to do.

In essence, the diet is done to ready the body for the stage of the race when glycogen is depleted. It’s at this point when most runners are hitting the proverbial wall. When everyone else began to hit the wall, Hill wasn’t. He easily passed the glycogen-depleted runners who were in front of him for most of the race.


These days, most endurance athletes load up on carbohydrates in the days leading up to a race, but leave out the depletion part. By loading up on carbohydrates they are ramping up their glycogen stores. This is as it should be. Just the same, there is a point where you can’t store more glycogen. Once your stores are maxed out, eating more pasta in the days before the race won’t increase the amount you have stored.

Ultimately, most endurance athletes have enough glycogen to get them through about the first 18-22 miles of a marathon. This of course varies depending on how many miles are spent running in the anaerobic zone. Unfortunately this is where most runners spend their time as opposed to the more sensible and glycogen-conserving aerobic, fat-burning zone.

The main reason the carbohydrate depletion diet for endurance athletes lost favor over the years is because it was just too difficult. It can also be dangerous. If done properly, the depletion segment of the diet will leave a person in a very weakened state for a couple of days. This can result in injury or illness. At the very least you will feel crappy and a million miles away from running a marathon if you’re doing the diet properly.


If you don’t follow the diet exactly, there’s no point in wasting your time doing it.

When Ron Hill implemented the diet for the marathon in the Munich Olympic Games of 1972, his timing was disrupted by the terrorist attack. The race date was changed and it threw the depletion and loading out of sequence. As a result he did not have the race he was expecting.

I did go on this diet several times back in my marathon days in the late 70’s and early 80’s. So I know exactly how it feels to go through it.


The process begins exactly seven days before your race. For this example we will assume your marathon is on a Sunday.

On the Sunday a week before your race your goal is to deplete your glycogen stores. A two hour or ninety minute run would accomplish this nicely.

carbohydrate depletion diet for endurance athletes

None of this during the depletion stage.

Once you deplete your glycogen stores, you do not replenish them. That means no more carbohydrates for you once you have done your depletion run. For the rest of Sunday, plus Monday, Tuesday, and Wednesday all you eat is fat and protein. No simple carbs or complex carbs. No bread, cereal, pasta, rice, donuts……..well you get the picture.

Your diet will be eggs, chicken, beef, fish and any other foods that provide little in the way of carbohydrates that can be converted to glycogen for fuel.

On Monday, Tuesday, and Wednesday go for a 30-45 minute run. This ensures complete carbohydrate depletion and will become more and more challenging with each passing day. By Wednesday, you will feel like death. If you have done everything right, you will have zero energy and the thought of running for 30 minutes much less a marathon will seem eminently impossible.


Begin the loading stage when you wake up on Thursday morning. Not Wednesday afternoon or at dinner on Wednesday. Thursday morning. If you begin loading to soon you screw up the depletion process and in that case, don’t bother going on the diet.

It’s almost remarkable how you can feel your energy level increase the moment you eat your oatmeal, toast, or/and hash brown potatoes on Thursday morning. It only gets better as you begin eating high quality carbohydrates Thursday, Friday, and Saturday.

Carbohydrate depletion diet for endurance athletes

Whole wheat bread is an excellent source of complex carbohydrates

If nothing else, trying this carbohydrate depletion diet for endurance athletes will once and for all educate you on just how important carbohydrates are as a source of energy.

For all those who write their books about how carbohydrates are bad for and unessential, I defy them to do the depletion stage of this diet and then run a marathon. Or for that matter, run around the block.

What a load of crap.

Going into a race devoid of glycogen stores is like getting in your car for a 100 mile road trip with a tablespoon of gas in the tank. It would be like trying to run a marathon on Thursday morning after denying yourself carbohydrates for four days.

I physically cringe when someone writes that carbohydrates are the root to all diet evil. They proclaim that it’s carbohydrates that are the major cause of obesity and poor health in general.

The reason for obesity in most cases is much simpler than that. If you consume more calories than you burn, your body will store it as fat for future use. That’s the message you are sending it. It doesn’t matter if those calories come from fat, protein, or carbohydrates.

As far as this carbohydrate depletion diet for endurance athletes goes, I believe it’s worth trying at least once if you’re are hard core runner.

Just be sure to spend a lot of time in your aerobic, fat-burning zone in the first half of the marathon. If you can do that along with this diet, you should be passing a lot of people who are walking, or running very slow, in the last five or six miles of the race.

You might also enjoy this article on complex carbohydrates for endurance athletes.