The fall seems to be the time of year when many runners and walkers enter into my office complaining of fatigue, cramping and poor recovery. What is special about the fall? With marathon events planned for October and November, most people on a training routine have started 2-3 hour workouts in August and September that leave them feeling drained and exhausted. Sport nutrition for long distance runners and walkers is one of my favorite consultations because the solution is so simple. Most runners don’t take in enough fluids and fuel to keep their bodies going over 2 hours. Water is adequate for re-hydration when exercising for 90 minutes or less. When workouts exceed 90 minutes the body begins to run out of easily accessible sugars. If you are only taking in water, the result is a drop blood sugar and all the associated signs of fatigue that follow: difficultly concentrating, headaches, nausea, muscle weakness. The solution to all of these symptoms is to consume a source of carbohydrate along with fluids to keep blood sugars stable until the workout is complete. In the case of a marathon, the time to complete will span well over 2 hours depending on your speed. A typical marathon (42.2km) will take between 3-5 hours for someone to complete. To avoid early fatigue and ensure your body has the fuel to finish the solution is simple. Consume about 40-50 grams of carbohydrate per hour and drink between 500ml to1litre of fluid per hour. Sound easy? The solution may be simple however the practice is sometimes difficult. Many runners and walkers are not used to eating and drinking adequately while exercising. Shorter distances can afford lesser quantities of food and fluids. But once you get to a 3 hour run or walk it takes some effort to plan out how you will carry and consume 1.5 litres of fluid to meet the minimum hourly recommendation. My advice to marathoners is to set out a plan of what they will eat and drink during the marathon and then practice those quantities during training. For example, a typical race plan may include 500-750ml of water for the first hour since carbohydrates are not needed until 90 minutes. In the second hour switch to a sport drink (preferably the one they will offer at the race). Most sport drinks will provide approximately 25 grams of carbohydrate per 500ml. Therefore, simply by consuming sport drink instead of water you are getting much of the carbohydrate your body needs. To get closer to the recommended 40-50grams of carbohydrate many people will consume a “gel” which is a concentrated sugar solution providing about 25g of carbohydrate. Other carbohydrate choices include crackers, sport bars and fruit. Don’t forget however, to also consume enough fluids so you can digest those carbohydrates. One common mistake is to consume a “gel” with only few sips of water. This can result in stomach cramping and bloating. If you have a sensitive stomach you are better off getting most or all of your carbohydrates from sport drinks which are designed for easy absorption. A little extra attention to carbohydrate and fluid intake will dramatically improve your endurance and enjoyment for marathon training.