Eat Breakfast, Exercise and Be Happy

Breakfast of eggs sausage fast and coffee.

Eating breakfast before exercise leaves you feeling better and less fatigued a recent study shows.

A defining part of my college experience was slumbering through class in a tired, grumpy stupor. I was a collegiate runner, which meant six days a week I would wake up and go straight to cross country practice without breakfast. My body was forced to grind through workouts on the daily coming off an overnight fast. A study published earlier this year in Appetite (yes, this a scientific journal, not a food catalog as its name might suggest) found that eating breakfast before exercise attenuates feelings of fatigue and lifts mood later in the day. This holds true even if a recovery snack follows the exercise bout. Breakfast before exercise, it turns out, positively effects cognitive performance, mood and fatigue later in the day (Breakfast consumption and exercise interact to affect cognitive performance and mood later in the day.  A randomized controlled trial, 2013.  Veasey, et al.).

The design of the study is depicted in the figure below. Male subjects were assigned to participate in four different trials in a randomized order. The trials were no breakfast, no exercise; breakfast, no exercise; no breakfast, exercise; breakfast, exercise. The exercise protocol entailed running on a treadmill at 60% of VO2 Max. Subjects performed cognitive tasks to assess mood and cognitive functioning seven different times over the course of the experiment. 

study experiment design or overview

The results of the study are as follows.  Breakfast consumption, regardless of whether the subject exercised or not, left the subject with slower cognitive function.  This was assessed with four choice reaction time accuracy. “Food comas”, apparently, cause poor reaction time in addition to leaving us tired. The figure below shows this result.

 The effect of breakfast consumption or omission (B or NB) on Four Choice Reaction Time accuracy following a mixed-macronutrient drink in active males. Values are change from baseline ± SEM, ( n  = 12).

To assess cognitive function a Stroop test was administered. The Stroop test involves naming the color font or a word. For example, [YELLOW]. The answer would be green.  Those who ate breakfast, but did not exercise, performed the worst on the Stroop test. Eating breakfast and exercising increased accuracy on the Stroop test, as did fasting and not exercising. Exercising and skipping breakfast caused the best reaction time. Not surprisingly, exercising and skipping breakfast resulted in the most fatigue. However, eating breakfast before the bout of exercise fully eliminated all exercise-induced fatigue. These fatigue measurements were taken after a chocolate milk recovery drink was administered to subjects in all four trials. Finally, while exercise without breakfast beforehand caused the highest amounts of tension later in the day, eating breakfast before exercise eliminated this tension.  

The effects of prior breakfast consumption or omission (B or NB) and exercise or rest (E or NE) on (a) Stroop accuracy (b) rapid visual information processing task reaction time (c) mental fatigue and (d) tension

While this study is intriguing, it has several problems. First, we must remember that the aforementioned cognitive and mood assessments are performed with standardized tests, that may or may not translate to everyday life. Second, subjects were allowed to read and relax between tests; in other words, it was a very relaxed environment that may not mirror our daily lives.  

It should be noted that the subjects had 120 minutes between breakfast and the exercise bout.  For many people, this is not practical for two reasons. First, one would have to start eating breakfast prior to 6:00 am to get a 8:00 am workout in. Second, for many people, myself included, 120 minutes is not enough time to digest food before a tough workout.

Nonetheless, this study highlights some interesting interactions between breakfast, exercise and our cognitive state later in the day.

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