That said, if you are a profuse sweater (your shirt and shorts are always saturated post-exercise), you may need to take in extra sodium 24 hours before the race start. Increasing sodium chloride consumption by 800 to 2,000 milligrams during your pre-race dinner is the recommended dosage. For those of you that need additional sodium, try soup, which typically is high in sodium but low in calories and fat.
Remember, however, that your increased dietary sodium requirements should be established by trial and error during training days that closely replicate race-day conditions.
3. Easy on the Water
Don't over-hydrate with water before an event. We're not camels. Humans can't store an infinite amount of fluid nor is it advantageous to try and stock up on water. Excessive fluid intake, primarily water, can begin to dilute the cellular sodium levels, leading to hyponatremia. If you're urinating every three to four hours over the final two days, this is generally a solid indication of adequate hydration.
Before the race, take in six to 17 ounces of fluid-replacement drink within 10 minutes of competition. This fluid will be used during the event, and the extra sodium and sugar will be absorbed, assuming your race breakfast was consumed two to 2.5 hours prior to this drink. If you've never done this, start with six to eight ounces. Hotter conditions and larger athletes typically demand more fluids than do cooler conditions and lighter athletes.
4. Don't Overeat Early On
Once you're out of the swim, don't overeat or drink for the first 30 minutes on the bike. Science says that during the race you only need to replace about 25 to 35 percent of the calories you burn. Experience says that the calories burned on the swim don't need quick replacement.
So at the beginning of the bike, simply wet your mouth with fluid during the first 20 minutes, then take a small sip (around two ounces) of water or fluid-replacement drink 20 to 30 minutes into the bike. Continue sipping two to four ounces at a time between 30 to 40 minutes, then drink at 12- to 15-minute intervals to finish out the hour, taking between four and 10 ounces every 12 to 15 minutes. The total fluids consumed during the first hour of the bike should range from eight to 24 ounces.
In extremely hot conditions, this number should be higher by 15 percent. Think of your nutritional plan really starting at 40 minutes into the bike. In the above scenario, you may have taken in only 15 to 20 percent of your total calories burned. For each successive hour, this percentage should climb to 25 to 35 percent.
Over the final 10 kilometers on the bike, increase your fluid intake. Once you're off the bike, there'll be an immediate increase in your sweat rate since you no longer benefit from the cooling effect of the wind. Prepare for this by ingesting an additional four to eight ounces of fluid-replacement as you near T2.
5. Combine CHO and PRO
Consider ingesting a carbohydrate/protein fluid-replacement drink during your race. Numerous studies have confirmed the synergistic insulin response from a combined CHO/PRO drink. During longer competitions muscle catabolism and glycogen conservation has also been enhanced by a mixed CHO/PRO drink.
The nutritional choices available today are a vast improvement over those offered just a decade ago. Reduce the guesswork and remove a potential source of stress by formulating a race-day nutritional plan by combining what has worked well for you in training with the above guidelines.
Recalling my fig days, I thought figs would be my secret weapon. They're loaded with carbohydrates, contain lots of water and are high in magnesium, but in reality they are a race-day disaster. Figs have fiber—lots of it, and in a long race fiber is not your friend.
Six-time Ironman World Champion Dave Scott lives in Boulder, Colo., and maintains a busy schedule running his own business as fitness and nutrition consultant, product marketing consultant and nationally recognized speaker. He also organizes or is the main keynote for fitness camps, clinics and races and is a regular columnist for many print and online sources. As an Active Expert, Dave utilizes his years of experience by offering unique and creative training plans for athletes of all abilities. Contact him at firstname.lastname@example.org.