So, How Many Calories Do I Need?

People are always surprised when I calculate out how many calories they need when they’re training. An average woman need about 1,200 calories just for her resting metabolic rate. That’s just what your body needs to run all it’s systems. She’ll need about another 600 calories for normal daily activity. So basically, not counting any exercise, the average female needs about 1,800 calories a day.

Now comes the shocker—the calories needed to support your training, stay healthy, and maintain your weight. On average you need about 100 calories per mile. This actually varies depending on how much you weigh. If you weight 120lbs you’ll need about 95cals per mile. It goes up about 15cals for every additional 20lbs of weight. So, a 180-pound individual will need about 140cals per mile.

For ease, lets say the female from earlier weighs 120lbs. The extra calories she’d need on a day she’s running a 6-miler would be 570cals. Her total calorie need for the day would be 2,370cals (1,200 + 600 + 570). This surprises many people, because they’re used to seeing diets that have you eating something crazy like 1,500cals a day. Now remember the 2,370cals is on a day you’re running a 6-miler. If you’re not running you won’t need those additional calories.

Why do you need those calories? Well, think of it as fuel. Let’s say you typically put $40 gas in your car each week. If one week you decide to drive across the country, that $40 of gas isn’t going to get you there. Same thing with calories. Not only do you need those calories for fuel, you need those calories for rebuilding and repairing muscle tissue after your run. In this case less is not more.

Now if you want to lose weight, you can decrease your calorie intake some in order to shed some pounds. Decreasing your calorie intake by 3500 calories in one week (500cals per day) should result in a 1lb weight-loss for that week. I can see the light-bulbs coming on….many of you are saying, “Cool, I’ll just not add those extra 570cals for running and I’ll be good to go.” Problem is, doing that doesn’t account for the calories you’re going to burn on your run. So you’ll end up with a huge calorie deficit and by not adding the extra fuel it’s going to take longer for you to recover from your run.

Nancy Clark (author of Nancy Clark’s Food Guide for Marathoners, Meyer & Meyer Sport, 2007) recommends that you should first calculate your calorie needs and then target 80% of that total calories in order to safely get the needed calories for daily living and your added exercise and still lose weight.

Here’s an example using the female runner from above.
1,200cals (to support metabolic rate) + 600cals (to support normal daily activity) + 570cals (to support 6-mile run) = 2,370cals (to support this day’s activity while maintaining the athlete’s weight).
80% x 2,370cals = 1,896cals (cals needed to support the daily activity and lose weight).

Many people (athletes or not) complain about feeling hungry throughout the day, especially if they’re trying to lose weight. One way to help avoid this hungry feeling is to try eating more frequently throughout the day. Instead of 3 traditional meals, try having 5-6 smaller meals throughout the day. You’re not going to be eating more calories, but you’ll spread it out over the course of the day. Your body actually burns calories while it’s digesting, so if you feed the fire more frequently, it keeps that engine burning longer.

If it’s easier, to still think of your 3-meals a day, that’s fine. Just make those meals smaller and then add a healthy snack in between those traditional meal times. Also, be sure to eat foods that are going to provide you with energy and have lasting power. Whole grains, nuts, fruits and veggies are great choices. Quaker makes a great oatmeal (Quaker Weight Control Instant Oatmeal) that I eat every morning. The name is a little misleading. The reason it’s “weight control” is because it has more protein than regular instant oatmeal which helps keep you fuller longer. A handful of raw almonds make a great mid-morning snack. Drink a glass or water with them and it will cause the nut fiber to expand helping you to feel fuller. Almonds also help to build your immune system. Lowfat yogurt as a mid afternoon snack is a great choice. Greek yogurt is packed with protein and really does the trick in keeping hunger at bay for me. Just be sure to get the 2% or no-fat variety.

So, it’s a little work, but keep track of your caloric needs, especially if you’re training and doing a lot of running. Your body will thank you and the fruits of your labor will show up in your training and in your renewed energy!