Calories Burned Running A Half Marathon

The half-marathon is a popular racing event that covers a distance of 13.1 miles--getting its name from being exactly half the distance of a full marathon. Throughout the course, runners face can face a series of hills and turns that create a challenging course. Runners burn a significant number of calories as they run a half-marathon, and the total number of calories burned is dependent on several factors.

Features

Three main features are involved in the calories burned during a half-marathon--body weight, age and sex. For example, a runner weighing 225 lbs. is going to burn significantly more calories than a runner weighing 180 lbs. As age and sex changes, the resting (basal) metabolic rate will also change, thus changing the number of calories burned during a half-marathon. Older runners will have a lower resting metabolic rate; females will have a lower resting metabolic rate than males.

Time Frame

Lasting anywhere from just over one hour to over two hours in length, the source of the calories burned will change throughout the race. During the first few minutes of the race, the body is utilizing the phosphagen metabolic pathway for energy supply that uses ATP as the main energy source. As the race continues, the body turns to the glycolytic pathway and utilizes carbohydrates for energy. When the race enters the second hour, the body starts to burn fat for energy as it is using the oxidative pathway as the number one source for energy.

Calculation

For a rough estimation on the number of calories burned during a half-marathon, formulas are available that use your body weight to calculate the calories per mile. For the total calories burned per mile, including the resting metabolic rate, use the equation (0.75 times body weight in pounds). For only the net calories burned per mile, use the equation (0.63 times body weight in pounds).

Example Calculation

A 27-year-old male runner weighing 175 lbs. will burn a total of approximately 1,700 calories for the entire half-marathon with 1,400 of those calories coming strictly from running. Using the previously described equation for total calories, 0.75 times 175 lbs.= 131 calories per mile and 1,700 calories per half-marathon.

Considerations

Several factors can influence calories burned during a half-marathon that could increase or decrease the total calories. For example, temperature and humidity will have a direct impact on the calories burned. The individual pace per mile will also affect calories- as the pace increases the number of calories burned will also increase. Consider replenishing calories before, during and immediately after the half marathon with fluids, gels and energy bars.