Nutrition For Endurance Hiking

We all know – hopefully – that physical conditioning is key to a successful and enjoyable backpacking or hiking trip.

You must get all your muscles ready for the extra stress of carrying weight, the rocky, uneven terrain, the elevation changes and the length of time you may be on the trail. But you also need to remember that these muscles need fuel in order to function efficiently and effectively, not only during your training, but also during the day of your event or trip. This blog article is to help you figure out what you need to consume to avoid “bonking” or “hitting the wall.” It will be a bit techie so bear with me and I will try to explain the concepts as painlessly as possible.

Key Terms

Glycogen – the molecule that functions as a long term energy store in animal and fungi cells and is made by the liver and muscles. This molecule forms an energy reserve that can be mobilized when a sudden need for glucose arises. It is the lack of glycogen that causes “bonking” or “hitting the wall.”

Glucose– a simple sugar that is a the main source of energy in biology. Every carbohydrate you consume can eventually be broken down into glucose to be used as energy. Glucose can also be stored in the body when it is not needed immediately for energy in the muscles and liver as glycogen.

Carbohydrate – the preferred source of energy for the brain and muscles. During digestion, the body breaks down carbohydrates from foods and beverages into glucose, which is transported to the liver and muscles to be used as energy.

Glycemic Index (GI) – the measure of the effects of carbohydrates on blood sugar levels. Carbohydrates that break down quickly and release glucose into the bloodstream rapidly have a high GI.  Carbohydrates that break down and release glucose into the bloodstream more slowly have a low GI. If you have ever participated in an endurance activity; such as a marathon, 150 mile bike ride, day long hike, etc. you may have “hit the wall.”  This means you did not consume enough carbohydrate that is critical for the maintenance of muscle and liver glycogen stores used during training or competition. The feeling is like none other; you can’t walk, run, saunter, stroll, trot, or just move PERIOD! Even sitting or standing still is rather uncomfortable. This is why it is essential that you consume the appropriate amount of carbohydrates before, during and after your long term activity. Many people who train for marathons and attempt to diet at the same time rarely finish the race, much less finish the training. After much ado, here are some guidelines to help you determine what you need to consume before, during and after your endurance activity to ensure success and a good time! For you math lovers out there, enjoy! Before you participate in your endurance activity (greater than 1 hour in length of moderate to intense activity), consume high carbohydrate food and drink 1 to 4 hours before your activity. Your food and drink should be low fat and moderate protein, additional to at least 16 fl. oz. of water.

Here’s the math…

• Consume 0.5-1.8g of CHO (carbohydrates)/lb of body weight.  This means for a person that weights 145 lbs, he or she needs to consume 72.5 to 261 grams of CHO.30-60 minutes before you exercise, consume a food that has a low GI, such as most fruits or vegetables or grainy breads.  But, you want to be sure what you choose is low in fiber. Fiber will take too long to digest and cause discomfort, or worse, during your activity. Foods you are unfamiliar with should also be avoided. So steer clear of the lutefisk (a little Scandinavia humor).

• Consume a snack that is about 0.3-0.5 g CHO/lb of body weight. During continuous exercise of greater than 1 hour, your goal is to maintain a consistent hydration/fueling schedule for a steady flow of glucose into your bloodstream.

• Drink 0.5 – 1.0 cups of fluid every 15 minutes

• Consume 30-60 grams CHO per hour: Snack every 10 to 30 minutes (as sport allows). This should be no problem when hiking or backpacking. In hot temperatures, consume snacks that are higher in sodium as well.  NOTE – “as the sport allows” means if you can eat food, that is the better option than electrolyte replacement drinks (Gatorade).  Electrolytes are better replaced via food than sports drinks and should only be used when necessary or when eating is not possible – such as when running or cycling.

You also have to remember to refuel after your activity to assist in muscle recovery and replace glycogen stores. Glycogen is restored most rapidly and efficiently within 2 hours after your activity and it takes 24-48 hours to fully recover used glycogen. This is why it is so important to eat after exercise, even if you do not feel hungry!  When it is hot outside, your appetite will decrease, so even more important. If you do not eat after your activity, you will find yourself eating twice as much later in the day or the next day as your body is trying to replenish energy and responding to perceived starvation.

• Eat a high carbohydrate, low fat, moderate protein meal (0.5 – 0.7 grams CHO/lb of body weight) (pasta dishes fit this criteria, add some pine nuts to the dish for a little extra protein)

• Eat high glycemic index foods such as sports drinks, bagels with jam, fresh fruit, crackers, etc.

• Replace lost fluids – at least 16 oz/lb of body weight lost (water weight lost in activity through perspiration).  This will be difficult to determine when in the wilderness so figure about 32 to 64 ozs of water at a moderate pace, with food.

Here’s an excuse to drink chocolate milk – if you need one. Chocolate milk is great after endurance activities to assist in recovery since it contains the optimum CHO to protein ratio. Now if you are still awake – enjoy your training!

Sources: Houtkeeper, Linda, Jaclyn Mauer Abbot and Veronica Mullins, Winning Sports Nutrition,  2007.

Benardot, Dan, Advanced Sports Nutrition, 2006.

Nutrition for Fitness and Sport Conference, University of Arizona, October, 2001.