Whether to avoid the afternoon heat or prevent workday chaos from interrupting an exercise routine, many individuals choose to partake in an early morning workout. This goes for recreational or professional athletes or active people alike.
Interest in appropriately fueling activity has caused many to question whether or not they need to eat something before an early morning workout. Like oh so many nutrition questions, the answer isn’t quite as simple as “yes” or “no”. There are several factors to consider when deciding not only whether or not to have something, but even what to have.
1. Intensity. The harder the effort, the more likely your body is to call upon carbohydrates (a fuel source in limited supply) to fuel the work. Yes, you can train your body to use more fat for fuel, however fat cannot be burned anaerobically. Carbs are important for being able to kick into a higher gear, and we have a limited capacity to store them as glycogen. Therefore, we sometimes need to top off the tank before a tough workout.
There is interesting research to show that it may be beneficial to “train low” on occasion – aka without a lot of carb stores on board. However, in the beginning it’s best to do this for low intensity and short duration workouts, and it should not be used for the majority of training. Heavy training with chronic low carbohydrate intake can lead to increased cortisol (a stress hormone) and reduced immune system response.
2. Duration. Technically speaking, the longer an endurance workout lasts the more fat is used for fuel (in particular beyond the 90 minute mark). However, largely speaking what changes the most is the ratio of carb:fat used based on intensity and duration. As I write this article at very low intensity, I am burning more fat for fuel (with a little bit of carbs)– if I start a sprint workout, the body shifts to more carbohydrate use. So carbohydrates are still the rate-limiting factor in the equation since their supply is limited. Again, you can train your body to use more fat for fuel for endurance workouts, however you may be limiting your max work output.
3. Type of activity. Different activities tap into different fuel sources in different amounts. A workout focused on strength work and power will use carbohydrates for anaerobic work, however it is typically not enough to deplete the system (if generally well fueled). Team sports, such as basketball, soccer, and ultimate frisbee, will typically have a good amount of anaerobic work and may use a good portion of carbohydrate stores. Endurance sports, such as running, swimming, and cycling, can place a heavy strain on carbohydrate stores and even lead to “bonking” – this occurs when body carbohydrate stores are exhausted and you are forced to slow down pace.
Considering these factors, here are some example scenarios where you may say yay or nay to the early morning pre-workout snack:
Times you may say “yes” to an early morning pre-workout snack
You are about to do a workout lasting 45-90 minutes that involves tempo work, high intensity intervals, sprint repeats, heavy weight lifting, etc. In other words, really hard work.
You had a tough workout (high intensity or long in duration) the previous night and this morning isn’t a “recovery” workout.
You have been consistently fatigued in workouts and routinely come down with the latest cough and sniffle.
You are about to do an endurance workout longer than 60-75 minutes.
Dinner the previous night was small or earlier than normal, or you didn’t refuel after last night’s workout.
Times you may say “no” to an early morning pre-workout snack
The morning workout is low intensity – a walk, recovery jog/swim/cycle, or a group class such as pilates or yoga.
You want to incorporate a “train low” workout once or twice during the week.
You are about to do a workout that is low to moderate intensity and less than 60-75 minutes.
You had a large snack before going to bed.
So if you do decide to fuel, what exactly should you have for an early AM workout snack? Here are some general guidelines and example foods:
The closer you eat to a workout (or race), the more easily digested, carb-focused the foods should be. Fat, protein, and fiber are slow to digest which can lead to digestive issues.
Typically 25-50 grams of carbohydrate is a good “snack” size for pre-workout.
Consider choosing a liquid source of carbs to also provide fluids.
EXAMPLE EARLY MORNING PRE-WORKOUT SNACKS
English muffin with jelly (or thin smear of PB if tolerated)
8-16oz sports drink
Gel, chews, etc.
2-3 Fig Newtons
½-1 cup reduced fat yogurt (non-Greek may be better tolerated)
1 cup dry cereal