For me, the subject of nutrition for runners has been one of the most difficult ones to tackle, simply because there is as much contradictory information out there as there are fad diets.
As of right now, Keto is one of the most popular “diets,” and while we are sure that it works (scientifically, it makes sense) as runners we are looking for a “lifestyle” that works best for runners that want to feel fresh and run strong (and even within those of us that have this goal there are variations i.e. not every runner has the same body composition or runs the same weekly mileage etc.)
Carbohydrates are fuel for runners
In order to have a positive running experience it is important to understand that carbohydrates are fuel for runners. Nevertheless as runners we have many more questions such as should we eat before we run, should we eat during runs, and what about after runs? Also, what should we eat, and how much of it? What about race fueling? What about hydration?
Let’s break down a little bit of what we have learned from talking to many books, nutritionists and registered dietitians is the following:
Muscle cells have two sources of fuel: sugar (from carbs) and fat, which come from either the food we eat or from what we have already stored in our bodies.
When we eat carbs, they are broken down into simple glucose (simple sugar), which circulates in the bloodstream and powers your cells. The glucose that is not immediately needed is stored as glycogen, in muscles and liver. When we run, we use this sugar from the bloodstream, and after we have exhausted that, we use the stored glycogen. According to Dietitian Kate Patton, MEd, RD, CSSD, LD, about 50% to 70% of your diet should be carbohydrates from healthy sources. Healthy sources are also important when it comes to your protein intake.
The fat we consume also is used during endurance exercise, but it is less immediately available for fuel, due to the fact that it has to be broken down into fatty acids before it can be used by the muscles as fuels. Stored body fat, however, is a great source for fueling because we all have it.
Your protein intake, on the other hand helps build and repair muscle tissue. The right amount of protein promotes muscle growth, especially when you do strength training.
Last but not least, staying hydrated is also important, because as your muscles generate heat, your body needs to get rid of that heat to maintain a normal temperature, and it does so through sweating. Sweating in turn reduces your body’s water level, and this loss of fluid needs to be replenished during and after your activity.