Pre-Exercise Nutrition

In past blogs, I’ve talked about strategies for properly fuelling during and after exercise (part 1 and part 2). I’ve even posted a blog on fasted exercise training. If you read this blog, which I highly recommend you do, then you know that in some circumstances there is a metabolic advantage to training “on empty.” However, more often than not, the pre-exercise goal should be to go into a workout properly nourished. This is especially true for hard workouts and competitions. So, what are the nutrition guidelines for before exercise?

The goal of pre-exercise nutrition is to provide energy for your workout and a fuel source for your working muscles. Pre-exercise nutrition is important to prevent feelings of hunger during a workout. As you may have experienced, it’s difficult to give your workout your best effort or to stay focused when all you can think about is how hungry you are. Ensuring that you’re properly nourished also helps to extend time to exhaustion.

Pre-exercise nutrition guidelines are complicated because they’re so individualized. One size does not fit all. We all know that one athlete who can eat a cheeseburger and fries before a workout with no GI issues (not that I would recommend trying this), while other athletes feel that they cannot tolerate a single bite. Guidelines are also complicated because optimal pre-exercise nutrition depends on when you are planning to exercise and how much you have consumed up until that point. Is it first thing in the morning and at a time when you haven’t consumed any food for 10 hours? Or is it mid-afternoon after going out for a big lunch with colleagues?

In general, it’s best to have a small meal or snack about 2-4 hours before exercise. Foods that are high in carbohydrates are usually best since they are more easily digested. For exercise lasting longer than 60 minutes, a carbohydrate target of about 1-4 g/kg about 1-4 hours before exercise has been shown to enhance endurance or performance of prolonged exercise. For instance, a 65 kg marathon runner should aim to consume 65-260 grams of carbohydrates before his or her weekly long run. Wondering what that looks like? Check out the table below for the carbohydrate content of some high-carbohydrate foods:

On the other hand, foods high in fibre, fat and protein should usually be avoided before exercise in order to reduce the risk of GI issues during exercise. The more food that is consumed before exercise, the more time needed to digest the food. Here is general pre-exercise nutrition guidelines based on the amount of time before exercise:

3 Hours Before Exercise:

• Normal meal
• Provides carbohydrates and moderate amount of protein and fat
• Examples: turkey sandwich, pasta with light tomato sauce

2 Hours Before Exercise:

• Meal provides mostly carbohydrates
• Meal provides little protein and fat
• Examples: low fat yogurt with berries, low fibre cereal with low fat milk

1 Hour Before Exercise:

• Light meal
• Very little protein, fat and fibre
• Examples: homemade fruit smoothie, english muffin with jam

Less than 1 Hour Before Exercise:

• Light carbohydrate snack
• Examples: banana, applesauce

What works best for you should be determined through trial and error. However it’s never a good idea to try out a new snack or meal on competition day. You should have a competition day fueling plan in place beforehand. I personally have a hard time eating before my long run. In preparation for my marathon, before every long run, I would try out a different pre-exercise meal and then write how I felt during my run. I was then able to reflect on these different meal experiments and determine what was my most optimal race day meal.

In an upcoming blog, I’m going to talk about runner’s gut, more commonly known as the lovely runner’s trots, so stay tuned. However, as a sneak preview, for those who experience an upset stomach while exercising, try a liquid snack such as a smoothie or Gatorade.

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