The idea is that you are supposed to consume carbohydrates and proteins in a magical four-to-one ratio during endurance events like a long run or bike ride, and right after. The belief is also that such nutritional diligence will improve your performance and speed your recovery.

There are grains of truth to the nutrition advice experts say but, as so often happens in sports, those grains of truth have been expanded into dictums and have formed the basis for an entire industry in “recovery” products. All these products line the shelves of specialty sports stores and supermarkets with names like Accelerade drink, Endurox R4 powder, PowerBar Recovery bar, to just name a few. 

As a group, athletes are particularly gullible. The idea that what you eat and when you eat it will make a big difference in your performance and recovery “is wishful thinking.

Here is what is known about proteins, carbohydrates and performance.

During exercise, muscles stop the biochemical reactions used to maintain themselves such as replacing and resynthesizing the proteins needed for day to day activities. It’s not that exercise is damaging your muscles; it’s that they halt the maintenance process until exercise is over.

To do this maintenance, muscles must make protein, and to do so they need to absorb amino acids, the constituent parts of proteins, from the blood. Just after exercise, perhaps for a period no longer than a couple of hours, the protein-building processes of muscle cells are especially receptive to amino acids. That means that if you consume protein, your muscles will use it to quickly replenish proteins that were not made during exercise.

Now comes the big misunderstanding. Muscles don’t need much protein. Twenty grams is as much as a 176-pound man’s muscles can take. Women, who are smaller and have smaller muscles even compared to their body sizes need less then that.  10 to 15 grams of protein is probably adequate for any adult and you don’t need a special drink or energy bar to get this in the body. One egg has 6 grams of protein. Two ounces of chicken has more than12 grams.

Muscles also need to replenish glycogen, their fuel supply, after a long exercise session, two hours of running, for example. For that they need carbohydrates. Muscle cells are especially efficient in absorbing carbohydrates from the blood just after exercise.

Once again, muscles don’t need much; about one gram of carbohydrate per kilogram of body weight is plenty. For an athlete that weighs 70 kilograms, or 154 pounds, this means he would need 70 grams of carbohydrates, or say, 27 ounces of fruit juice. The fastest glycogen replacement takes place in the four hours after exercise. Even so, most athletes need not worry.

Most athletes will have at least 24 hours to recover and then we really are talking about a group of extremely elite sports people who train twice a day. For them it can be necessary to rapidly replenish muscle glycogen.

The American College of Sports Medicine, in a position paper written by leading experts, reported that athletes who take a day or two to rest or do less-intense workouts between vigorous sessions, can pretty much ignore the carbohydrate- timing advice. When sufficient carbohydrate is provided over a 24-hour period, the timing of intake does not appear to affect the amount of glycogen stored.

For protein, it is not clear what the window is. Some studies concluded it was less than two hours, others said three hours, and some even failed to find a window at all.

Although studies have shown that consuming protein after exercise speeds up muscle protein synthesis, none has shown that this translates into improved performance. The reason is that effects on performance, if they occur, won’t happen immediately. They can take 6 to 10 weeks of training. That makes it very hard to design and carry out studies to see if athletes really do improve if they consume protein after they exercise.

As for the special four-to-one ratio of carbohydrates to protein, that, too, is not well established, researchers said. The idea was that you need both carbohydrates and protein consumed together because carbohydrates not only help muscles restore their glycogen but they also elicit the release of insulin. Insulin, the theory goes helps muscles absorb amino acids.

Insulin may stimulate muscle protein synthesis in young rodents and in human cells grown in petri dishes but studies in people have shown convincingly that insulin is not required for protein synthesis in adult human beings; it is amino acids that drive protein synthesis. As yet no convincing evidence exists that a special carbohydrate- to-protein ratio makes a noticeable difference in muscle protein maintenance after exercise. There is no magic ratio or number.

Even if there are effects of protein and carbohydrates, they are not important to most exercisers. Serious triathletes and elite runners, who work out in the morning and at night, need to eat between training sessions. People who are running a few miles a few days a week don’t need to worry about replenishing their muscles.

If you are a super athlete and have to perform on the highest level and where other factors are important as the performance hundredths of a second matter but in reality most Joes and Janes are just kidding themselves.