Ask a Dietitian

As seen on BCTV Noon News

Fueling The RACE from start to Finish

There are more and more marathons and Iron Man competitions available year-round and if you compete, you need to pay close attention to your diet.  Food essentially provides the fuel that your body will use during your training and on the competition day. The key is to have enough stored energy in your body to keep you going. The following are eating for energy tips for before, during and after the big marathon race.

1.      Hydration is key, and one should start pushing those fluids at least 24 hours before hand. Keeping a water bottle with you at all times is a great way to remind yourself to drink up. Being adequately fueled for the start of the race is also important as every mile burns approximately 100 calories. Carbohydrate loading is an option to reduce the chances of “bonking” or “hitting the wall” during the race. Carbo-loading does not require eating excessive amounts of food or loading up on high fat foods. It simply requires increasing the percentage of your daily diet of carbohydrate-rich foods and tapering your activity in the week and days prior to the event.

2.      A breakfast high in carbohydrate before the race is also important. This will assist in topping up your glycogen stores (mostly in your liver) and is critical for blood sugar maintenance during exercise. It should be low in fat and fibre and contain some protein.  Experiment during training sessions with different foods to find what combination works best for you.

3.      During the race, it is important to save your glycogen stores and extend the distance you can run. Consuming energy drinks and pudding-like energy gels while running can help to keep your energy reserves high. While drinking your calories remains the easiest way to increase your energy, gels are also a good option and provide 20-30g CHO/serving.  Your goal is to have 0.7g/kg body weight/hour.  Gels must be consumed with 4-6 ounces of water to avoid gastrointestinal discomfort, so aim to eat them right before a water station.

4.      Glycerol is an option to hyperhydrate your system, especially in situations of higher temperatures. However, this should definitely be experimented with during long training sessions before the race day.  Consult an expert before using Glycerol on your own.

5.      “Hitting the wall” is essentially when a marathoner has depleted all muscle glycogen stores. The individual’s legs will feel like they cannot go on and energy levels will drop despite continuing to take in calories. An athlete can often finish the race but usually with less than desired performance levels. “Bonking” is when the body completely shuts down due to both muscle and liver glycogen stores being depleted. A severe drop in blood sugar results and can potentially be very serious if left untreated. If this occurs the best idea is to stop running and get your blood sugar levels back up by consuming carbohydrates that are readily absorbable (eg. sports drinks, energy gels, glucose tablets). Training appropriately for the race and consuming adequate carbohydrates throughout training to increase your glycogen reserves will assist in preventing this.

6.      Hyponatremia (low blood-sodium levels) can also be of concern, particularly for those competing in hot weather. By maintaining or increasing your salt intake before the race, hyponatremia can be prevented. Individuals at the greatest risk for hyponatremia, are those not acclimatized to the heat, female marathoners and racers taking more than three hours to complete the marathon.

7.      Following the race, remember to hydrate and replenish your glycogen stores. In the first 30 minutes after the race, consume carbohydrates to assist in reducing muscle soreness and damage.

Watch for the Eating for Energy segment every Tuesday on BCTV’s Noon News Hour!