The next step was to create a specific "Pre Event" drink in order to attenuate dehydration and to provide an ergogenic buffering effect. This pre-event drink was used primarily in the time trials and contained sodium bicarbonate and sodium citrate mix in a proprietary ratio (sorry, can't give away ALL the secrets!), and a 1.5 percent sucrose concentration. The team used approximately 100 liters of this mixture during the race.
The goal of the "During" drink was to attenuate dehydration. Carbohydrate was generally supplied via food stuffs. The "During" drink was a proprietary ratio of sucrose:glucose, with sodium citrate, magnesium, b-vitamins and potassium. It contained no Sodium Choloride (NaCL); instead they used Sodium Citrate due to its decreased gastrointestinal stress and higher water retention rate and inherent buffering effect. The team used approximately 10,000 liters during the race.
The "Post" drink was intended to stop the stress response, rehydrate, and promote muscle repair and glycogen regeneration. It contained, among the list, a 1.5 percent solution of maltodextrim, potassium, amino acids, antioxidants, calcium, magnesium and vitamins. They mixed over 8,000 liters during the race.
Each of these drinks was formulated to be slightly hypotonic to increase absorption rates, since water goes into the higher solute compartment in simple osmosis. The drinks were <270mmol/L solution compared to the blood plasma which is ~285-290 mmol/L. The ideal composition included roughly 100 mmol/L of Sodium, 6 mmol/L of Potassium, and 1.5 to 2 percent CHO solution (most sports beverage drinks are in the 6 to 8 percent CHO range).
Carbohydrate was also optimized. A sucrose/glucose solution was used during the races as it provided the best balance between increased water and sodium absorption and the highest possible CHO load without negatively affecting the osmolality (an indicator of fluid balance and ease of transport across cell membranes).
The recovery drink used a 1.5 percent solution of maltodextrins, which are absorbed almost as rapidly as glucose with less gastric distress and impact on osmolality.
The Results
The validity of the project can be seen in a number of ways.
The preparation and acclimation component, especially the dehydration protocol, saw the athletes' red blood cell concentration rise by up to 4 percent, and total plasma volume to increase by ~7 percent. This is a natural ergogenic aid akin to erythropoietin supplementation.
There was also a decrease in exercising heart rate, an increase in work capacity and less total sweat loss during the race.
The "Pre" event drink was shown, anecdotally (n = 1), to increase power by ~7 to 8 percent on a 40-kilometer time trial from 365W to 385-390W (time equivalent of 57 seconds!).
During the race, the athletes routinely ingested two times the normal volume of liquid, yet suffered no GI distress. For the balance of the Tour the team used no IV drips! That is virtually unheard of in grand tours. At several points the athletes' urine was ruled "too dilute to test", a testament to the effectiveness of the hydration strategy.
On the results sheet, the team placed two riders in the top 10, and finished second overall in the team competition and team time trial. During the Stage 18 individual time trial the team had three riders in the top 10, all within a minute of the stage winner.
Summary
Each year a variety of new technologies and methodologies are rolled out in the search for speed and consistency. Technicians buzz around checking details, tightening torque wrenches and generally pondering the speed to be gained.
Similarly, the athletes and soigneurs engage in their own daily performance dance. Legs are embrocated, stretched and massaged. Food is constantly ingested and chased by fluids—prodigious amounts of fluids. All in the quest to take the athlete right to the edge of performance.
One of the most demanding elements of the race is the quest to maintain hydration, electrolyte balance and thermoregulation. This year, Garmin-Slipstream brought in a leading researcher to help create the perfect plan for the team. By combining a rigorous pre-event acclimation camp with the creation of some truly high-tech mixtures for each phase of the race, the team was able to succeed in the battle for results and the battle for the long term health of their riders.
With notable increases in work capacity, fluid retention and red blood cell volume, and with notable decreases in gastrointestinal distress, exercise heart rate and overall heat stress, it can be argued that this type of cutting-edge research and implementation was a key element in the team's success.
You can expect this project to make it into your list of hydration and fluid options within the next 12 months or so.
References
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- Sims ST, Rehrer NJ, Bell ML, Cotter JD. Preexercise sodium loading aids fluid balance and endurance for women exercising in the heat. J Appl Physiol 103: 534-541, 2007.
- Sims, ST, L vanVliet, JD Cotter, and NJ Rehrer. "Sodium loading aids fluid balance and reduces physiological strain of trained men exercising in the heat." Medicine and Sciences in Sports and Exercise, 39 (1), 123-130, 2007