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Nutrition and Recovery: Priming the Pump for Tomorrow

Written by Holly Ortlund, M.S.

Recovery- One of the most important aspects of any serious athlete's regimen. In order to be ready for the next intense workout or competition the body has to quickly rebuild and refuel itself. Athletes that take appropriate measures to eat well following exhausting exercise can reap significant recovery benefits.

Restocking the shelves
Most athletes are aware that blood glucose and muscle glycogen power their long workouts and competitions. And most athletes have nutritional savvy when it comes to planning their meals/supplements during exercise in order to maximize performance. But few athletes seem to realize the importance of nutritional needs in the early hours following intense exercise.

Because there is a direct relation between exercise fatigue and muscle glycogen stores, glycogen resynthesis immediately following exercise is vitally important in speeding recovery. Although the body is capable of replacing muscle glycogen loads within 24 hours, this timeframe is sometimes not available or practical to many individuals. Therefore, athletes competing in multiple day events or involved in heavy training sessions with less than 8 hours of rest are particularly in need of restoring glycogen levels as quickly and efficiently as possible.

To gain a better understanding of how to attain optimal rates of glycogen synthesis, it's important to get to know the major players involved:

                       Glycogen depletion
The amount of muscle glycogen depletion after exercise is a potent stimulator of glycogen production (10). In fact, low glycogen concentrations in the muscle increase both the rate limiting enzyme for glycogen synthesis, glycogen synthase, as well as the permeability of the muscle cell for glucose uptake. Put in simple terms, muscles are much more 'hungry' after a strenuous 2-hour workout versus a moderate 45 minute workout.

                       Carbohydrate availability
Glycogen synthesis after exercise relies on ingested carbohydrate, therefore, if inadequate amounts are consumed during recovery, glycogen stores will not be optimally replenished.

                       Insulin
Following exercise, insulin sensitivity in the muscle cell is increased. A very important hormone in the recovery process, the presence of insulin positively affects glycogen synthase activity and muscle glucose uptake.

                       Timing/Feeding Schedule
Replacing glycogen stores depends not only on what you eat, but when you eat it. The timing of carbohydrate consumption after exercise is crucial in achieving optimal results. This particular topic is explained in more detail later in the article.

                       Fitness level
We train to get faster, stronger and leaner (among other reasons). Training elicits numerous adaptations to the body; therefore, it's not surprising that training status is also an important influence for the ability to replace muscle glycogen levels. Trained individuals can show muscle glycogen storage rates that are twice as high as sedentary individuals following exercise (2).

Timing and amount of carbohydrate intake
Ingestion of carbohydrate is critical during the early hours after exercise. Glycogen synthesis rates can be as much as two-fold higher when carbohydrate is consumed immediately post-exercise as compared to a 2-hour delay (3).

How much is enough and at what time points should carbohydrate be ingested? Recent evidence points to an ideal feeding schedule consisting of 30 minute intervals at an amount of 0.4 - 0.6 g/kg body weight to achieve maximal glycogen synthesis rates (1,4,5,7,14). This equates to consuming roughly 0.2 g of carbohydrate per pound of body weight every half hour for a total duration of 4 hours (see table 1 below). Small and frequent feedings (i.e. every 30 minutes) appear to be more beneficial than consuming a large amount of carbohydrate once every 2 hours. This advantage is thought to be due to the body's inability to sufficiently increase and maintain blood glucose and insulin levels for a 2 hour period. (5,12)

Don't forget the protein!
Don't think only in terms of consuming carbohydrates during recovery; protein is another nutrient that merits significant attention. Protein and carbohydrate make excellent partners for post-exercise nutrition. When consumed together, the result is a synergistic stimulation of insulin release. Put more simply, the addition of protein amplifies the insulin response and promotes glucose delivery to depleted muscle cells.. Several studies have shown higher muscle glycogen storage rates following exercise when a carbohydrate-protein mixture is ingested versus carbohydrate only (6,14,17). The enhanced synthesis was attributed to higher levels of insulin as a result of the carbohydrate-protein mixtures.

In addition to affecting glycogen synthesis, insulin also plays a key role in protein dynamics. Insulin stimulates protein synthesis and helps reduce protein breakdown. Shortly following intense exercise, net protein balance enters a negative state if protein or amino acids are not consumed. In other words, muscle proteins are broken down to a larger extent than they are being rebuilt. The consumption of protein is therefore beneficial on two fronts; to boost insulin release but to also provide the basic building blocks for muscle repair.

Analogous to glycogen synthesis, a critical window also exists for protein synthesis during the early hours after exercise. So like carbohydrate, the timing of protein intake is very important during recovery. Several studies have shown significantly higher rates of protein synthesis and net protein balance when protein is ingested shortly after exercise as compared to delayed feedings of 3 hours or more (8,11,13).

As for how much protein to include in your recovery plan, shoot for a carbohydrate to protein ratio in the range of 2:1 - 4:1. The same chart from above is updated below with protein for better clarification