On a game day an athlete uses an extraordinary amount of energy throughout their competition. Using the entire day in preparation for their event at night usually. I am going to take you through the day of a Stanford soccer player and how we prepare for a game. A typical day we will wake up eat breakfast, for me that will consist of 3 eggs and a piece of toast. Next we hangout until lunch and I will typically go to subway to get a sandwich. Then, take a mid afternoon nap and after bike down to the field. Finally, we play our game and get pizza afterwards for dinner. Throughout the day we are extending energy in everything we do, while also replenishing it with the food that we eat. A small calorie, the amount of energy required to heat 1 cm2 of water by 1°C, is 4.184 Joues. A food calorie is 1000 small calories:
Throughout one of our games this season I had my tracker on for 169 minutes. Getting rid of half time and the time that I was not playing that means I was running for a period of 129 minutes (Table 1). At an average of 8 (kilo)calories a minute I would have burned 1032 (kilo)calories = 4.32 × 106 joules over the course of the game. I also biked for 20 minutes from my dorm to the locker room and back, which would have burned 800 (kilo)calories = 3.35 × 106 joules of energy.  Sleeping for another 9 and a half hours on average would have burned 595 (kilo)calories = 2.49 × 106 joules of energy. Then just sitting around resting waiting for the game, 12 hours and 1 minute, would have burned 1,033 (kilo)calories = 4.32 × 106 joules of energy. So throughout the day I burn roughly 3.460 (kilo)calories = 1.45 × 107 joules of energy.
|Table 1: VX tracker data from Stanford Mens' Soccer Quarter Final against Louisville on 3 Dec 16. (Source: C. Hyatt)|
I am also replenishing throughout the day with my breakfast, lunch, and dinner. During breakfast I will eat 2 pieces of toast and 3 eggs, a total of 370 (kilo)calories.  Lunch I will eat a foot long sandwich that will be around 734 (kilo)calories.  For dinner I usually eat around 3 pieces of pizza from what they give us after the game, which is around 1,005 (kilo)calories.  Thus, I consuming a total of about 2,109 (kilo)calories = 8.82 × 106 joules of energy throughout the day.
So on games days I use much more energy than what I am consuming. This is why I also feel so tired the days after and why it is important to get food in your body after physically exerting yourself. These days take a lot out of us and we all use the next few days to recover especially when we have lots of games in a short span of time. Most of the guys eat pretty similar meals throughout the day as I do before games so looking back after figuring out the numbers I should be replenishing my body with much more than I have been considering what I used throughout the day. Solutions could be eating more after the game or adding in a protein shake for those extra nutrients your body needs.
© Corey Baird. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
 P. C. Alvaro, A. S. Alston, and N. Katims, "Fractions Attack! Children Thinking and Talking Mathematically," Teaching Children Mathematics 6, No. 9, 562 (May, 2000).
 N. Clark, Nancy Clark's Sports Nutrition Guidebook, 5th Ed. (Human Kinetics, 2013).
 T. Dumanovsky et al., "What People Buy from Fast-food Restaurants: Caloric Content and Menu Item Selection, New York City 2007," Obesity 17, 1369 (2009).
 J. M. Brunstrom and P. J. Rogers, "How Many Calories Are on Our Plate? Expected Fullness, Not Liking, Determines Meal-Size Selection," Obesity 17, 1884 (2009).