Maintaining carbohydrate availability is a key challenge in multi-stage races. Races like the Des Sables Marathon, the Tour de France, the Vuelta a España, or an Ultraman are all races where one of the main nutritional goals is recovery. The better your recovery and the faster you are, the better your results will be the next day.
It's well known that there are thousands of recovery products available today, all very different from one another. This fact confuses many athletes, as they don't know what to choose when there are so many different options. In this guide, we want to help you choose the best recovery product available: GLYCOGEN. This recovery product has been scientifically designed by nutritionists specializing in endurance sports nutrition. We don't force you to buy our recovery product; our main goal is for you to understand how, how much, and when to take a recovery product, and to know how to choose.
A major challenge in multi-stage races, such as the Grand Tours and the Marathon des Sables, is maintaining adequate carbohydrate availability. This is because we rapidly deplete carbohydrate stores during exercise and have a limited carbohydrate storage capacity. Furthermore, when carbohydrate stores are low, we have difficulty maintaining exercise intensity at race pace. The storage form of carbohydrate in humans is glycogen, which is found primarily in the muscles and liver. It is believed that the maximum amount of glycogen an athlete can store is less than 3,500 kcal of energy. This is not enough to support even a full day of racing, and even if athletes consume carbohydrates during exercise, they will almost always end up with low glycogen stores at the end of each stage. Therefore, muscle glycogen recovery depends primarily on the dose of carbohydrate ingested post-race or training and its frequency over time.
Sports nutrition guidelines for exercise recovery typically state that to refuel quickly, athletes should aim to consume 1.0-1.2 grams of carbohydrate per kilogram of body mass per hour for the first four hours following exercise (1) . This means that a 70 kg person should be consuming around 70-84 g of carbohydrate.
This is based on substantial evidence that this rate of carbohydrate intake maximizes muscle glycogen replenishment rates. In terms of the types of carbohydrates consumed, this seemed to be less important, as muscle glycogen replenishment appeared to be similar whether the carbohydrate source was glucose-based or a mixture of glucose and fructose (2).
However, much of the previous work on glycogen replenishment has paid little attention to the effects of post-exercise nutrition on liver glycogen recovery. Liver glycogen availability may also be important for the capacity to perform prolonged exercise. Currently, compared with a single carbohydrate, short-term muscle glycogen synthesis rates after exercise are approximately 45% lower when glucose is the only carbohydrate consumed (3 , 4).
Total energy provision may be improved by ingesting beverages containing both glucose (maltodextrin) and free fructose compared with carbohydrate solutions containing only glucose. For example, Shi et al. (5, 6) demonstrated greater total intestinal absorption of carbohydrate at rest when glucose and fructose were ingested simultaneously compared with glucose alone. Furthermore, they reported improved oxidation and maximal delivery of ingested carbohydrate during exercise with combined glucose (maltodextrin) and fructose ingestion compared with ingestion of an equivalent amount of glucose alone. The enhanced carbohydrate delivery observed at rest and during exercise is attributed to enhanced total intestinal absorption of carbohydrate through stimulation of multiple distinct intestinal transporters (glucose and fructose absorption are facilitated by sodium-dependent glucose transporter 1 [SGLT1] and glucose transporter 5 [GLUT5], respectively), leading to increased systemic availability of ingested carbohydrate (7) .
Compared to muscle glycogen, liver glycogen metabolism appears to be more sensitive to the type of carbohydrate ingested. For example, co-ingestion of fructose with glucose-based carbohydrates strongly increases the rate of liver glycogen replenishment, but not muscle glycogen replenishment, after exercise (8, 9). The increased recovery of liver glycogen stores with fructose-glucose co-ingestion is typically twice that observed with glucose alone, even when the total amount of carbohydrate is identical.
Blends of fructose and maltodextrin during recovery improve subsequent exercise capacity
In a recent study, a group of runners performed two sessions of intensive running separated by 4 hours. During the 4-hour recovery period, the runners received carbohydrate drinks containing either glucose-based carbohydrates or glucose-fructose mixtures. After ingesting the glucose-fructose mixtures, the athletes were able to run approximately 30% further, compared to ingesting equivalent amounts of glucose-based carbohydrates alone (10). This was an exciting finding, suggesting that the type of carbohydrate ingested during exercise recovery could have an important effect on subsequent exercise capacity.
A more recent study addressed this by asking cyclists to perform exhaustive exercise and then consume either fructose-glucose mixtures or glucose-based carbohydrates alone for 4 hours after exercise (11) . Subsequent endurance capacity was then assessed after 15 hours of recovery, following an overnight fast and a low-carb breakfast. Surprisingly, endurance capacity improved by ~20%, suggesting that fructose-containing carbohydrates in the athletes’ recovery diet may improve their ability to perform exercise the following day.
In summary, a recovery should contain carbohydrates in an amount of 1-1.2 grams per kg of weight and that these carbohydrates be a combination with a ratio of 2:1 (maltodextrin: fructose), protein 0.3-0.4 grams per kg of weight, be a hypertonic drink to facilitate the entry of solutes around 1-1.5 grams of sodium per intake, contain the exclusive minerals excreted by sweat and not all of them.
That's why we created GLYCOGEN RECOVERY DRINK.
Literature
- Thomas DT, Erdman KA, Burke LM (2016) American College of Sports Medicine Joint Position Statement. Nutrition and Athletic Performance. Med Sci Sports Exerc48, 543-568
- Wallis GA, Hulston CJ, Mann CHet al.(2008) Postexercise muscle glycogen synthesis with combined glucose and fructose ingestion. Med Sci Sports Exerc40, 1789-1794.
- Blom PC, Hostmark AT, Vaage O, Kardel KR, Maehlum S. Effect of different post-exercise sugar diets on the rate of muscle glycogen synthesis. Med Sci Sports Exerc . 1987;19(5):491-6.
- Van Den Bergh AJ, Houtman S, Heerschap A, et al. Muscle glycogen recovery after exercise during glucose and fructose intake monitored by 13 C-NMR. J Appl Physiol . 1996;81(4):1495-500.
- Shi X, Schedl HP, Summers RM, et al. Fructose transport mechanisms in humans. Gastroenterology . 1997;113(4):1171-9.
- Shi X, Summers RW, Schedl HP, Flanagan SW, Chang R, Gisolfi CV. Effects of carbohydrate type and concentration and solution osmolality on water absorption. Med Sci Sports Exerc . 1995;27(12):1607-15
- Jeukendrup AE. Carbohydrate intake during exercise and performance. Nutrition . 2004;20(7-8):669-77.
- Décombaz J, Jentjens R, Ith Met al.(2011) Fructose and galactose enhance postexercise human liver glycogen synthesis. Med Sci Sports Exerc43, 1964-1971.
- Fuchs CJ, Gonzalez JT, Beelen Met al.(2016) Sucrose ingestion after exhaustive exercise accelerates liver, but not muscle glycogen repletion compared with glucose ingestion in trained athletes. J Appl Physiol (1985)120, 1328-1334.
- Maunder E, Podlogar T, Wallis GA (2018) Postexercise Fructose-Maltodextrin Ingestion Enhances Subsequent Endurance Capacity. Med Sci Sports Exerc50, 1039-1045.
- Gonzalez JT, Fuchs CJ, Betts JAet al.(2016) Liver glycogen metabolism during and after prolonged endurance-type exercise. Am J Physiol Endocrinol Metab311, E543-553.
