One way to achieve optimum performance is to focus on post exercise food choices. Since carbohydrates are the primary source of fuel during intense activities and are also used during endurance activities, the restoration of muscle and liver glycogen (the body’s storage form of carbohydrates) stores is important to allow proper recovery. An adequate intake of carbohydrates and energy through the diet will optimize muscle glycogen storage during consecutive days of hard training, and delaying the intake of carbohydrates may reduce muscle glycogen storage and impair recovery.
Two reasons that glycogen repletion occurs faster after exercise include:
1: Blood flow to the muscles is much greater immediately after exercise.
2: Muscle cells are more likely to take up glucose.
Benefits of Carbohydrates after Exercise:
Post exercise carbohydrates are most important for glycogen resynthesis in trainers who train hard several times per day such as swimmers, runners, or athletes who train with split session. Post exercise carbohydrates are also important for ultra endurance athletes such as those competing in triathlons, marathons, cycling events, where they do not have 24hrs to replenish muscle glycogen stores.
Most research on recovery has focused on glycogen repletion, and since glycogen is usually not depleted during intermittent activities such as with many team and skill sports, less is known about recovery in these situations. Although many sports like American football, English soccer, are all now replenishing carbohydrates after such games. However, studies do point to a more positive protein balance when carbohydrates were consumed immediately after intense resistance training.
How Much Should You Take?
After hard exercise lasting 90 minutes or longer, an athlete should consume 1.5 grams of carbohydrates per kg of body weight immediately after exercise and an additional 1.5g of carbohydrates per kg of body weight two hours later. Choose adequate carbohydrates to support your daily needs, studies have shown that as long as adequate calories are consumed, a mixture in the form of protein, carbohydrates, and fat is just as effective as carbohydrate alone at replacing muscle glycogen after an exhaustive bout of exercise. The addition of a small amount of protein may stimulate muscle protein synthesis post exercise, but does not enhance muscle glycogen synthesis.
What to Choose.
Choose adequate carbohydrates to support your daily needs. Studies reveal that as long as adequate calories are consumed, a mixture of carbohydrates, proteins and fat is just as effective as carbohydrate alone at replacing muscle glycogen after an exhaustive bout of exercise. The addition of a small amount of protein may stimulate muscle protein synthesis post exercise, but does not enhance muscle glycogen synthesis.
Liquid versus Solid Choices:
Athletes who are not feeling hungry right after exercising may prefer a high-carbohydrate drink (e.g. sports drink, fruit juice, or a commercial high-carbohydrate beverage) immediately after exercise which will serve to promote glycogen repletion as well as promote re-hydration. Both beverages and solid foods will help to promote glycogen resynthesis.
Choose High Glycemic Index Carbohydrates:
Data suggests that high glycemic index foods consumed after exercise replenishes glycogen faster than low glycemic index foods. Although a high glycemic index diet may be beneficial, it is important to recognise that the total amount of carbohydrate is the most important consideration for glycogen repletion. A daily carbohydrate intake of 6 – 10g per day is recommended for glycogen restoration for athlete’s engaged in heavy training for two to three hours a day.
Initial studies on glycogen repletion after complete depletion emphasised carbohydrate ingestion immediately after exercise. However other studies show that a delay of two hours does not inhibit glycogenesis, eight and twenty four hours later, as long as adequate carbohydrates are consumed over the course of the entire day.
Emphasis is usually placed on carbohydrate for post exercise consumption. However, in practical terms, consuming a balanced meal of carbohydrates, protein ensures the availability of all substrates needed for adequate recovery. Total daily carbohydrate intake is more important for optimal recovery than is the timing or type of carbohydrates.
By Neale Cranwell