Welcome to part 1 of my Eating the Burn series where I will be investigating what, how much and when I should be eating as I train for the Paris marathon. I recently outlined the reasons why I want to look into this massive area in more detail and if you want to read more about that, you can pop right over here !

In Part One of this series, I’m going to be comparing what I currently consume on a typical marathon training day with what I “should” be eating/drinking according to running books, magazines, articles, internet or whatever other sources of information available. I know a lot of you out there don’t like to talk calories or specifics and I fully respect the reasons why, but this post is shooting for the nitty gritty, the exact figures. I want to know that I’m getting enough – that I’m feeding my body with everything it needs to recover, repair and support my body during while training for a marathon. Long term, I’ve no intention of becoming a control freak with calories or working out the percentage of carbohydrates in my day, but for the purpose of this series, I want to ask the question: **Am I getting enough?**

I ran 10 easy miles today. This is what I ate and drank:

**Breakfast: ***I missed it because I was rushing and distracted…*

**Lunch:** Brown soda bread (2 slices), smoked salmon, ham, cucumber, baby spinach and a laughing cow cheese.

**Snack:** Big bowl of honeydew melon.

**Dinner:** Roasted mackerel fillets (x2), bulgur wheat, beetroot and rocket with a horseradish yogurt dressing.

**Supper**: A bowl of mixed berries, half an apple, half a banana, greek yogurt and a tablespoon of trail mix.

**Drinks:** 3 cups of black coffee, 2.5 litres of water and 2 mugs of green tea.

Now for a chart! And after some painstaking calorie mathematics (not to mention hours of my life I will never get back… ) Voila!

Meal: |
Calories |
Carbohydrates |
Sugar |
Protein |
Fat |
Saturated |
Fibre |

Lunch | 262 | 33g | 1.9g | 22.7g | 4.7g | 1.2g | 6g |

Snack | 117 | 25.2g | 25.2g | 2.4g | 0.6g | 0.5g | 2.4g |

Dinner | 540 | 38g | 2g | 35.1g | 26.5g | 5.2g | 0.3g |

Supper | 293 | 46.1g | 29.7g | 13.2g | 6g | 3g | 5.1g |

My day above worked out at a total of **1203 kcal,** which works out at about **26 kcal/ kg LBM**. (*If I had eaten breakfast, eg porridge, it would work out around 1500 kcal*)

**The Bloody Biology Mathematics: **Not to put you off, but there are numerous different calculators and mathematical equations used to estimate your daily caloric needs. Some result in very similar figures, while others do not and as you will see from below, I found that there can be quite a variation between them. Below are a few different sources to calculate your daily caloric needs. I used a few different ones not to confuse you but to compare them and see if the results are the same or similar… or not!

(1) **Bodybuilding.com. **They say that to determine your basal metabolic rate (BMR), aka how many calories your body burns at rest, use the following formula:

W = weight in kg (weight (lbs)/2.2)

H = height in centimeters (inches x 2.54)

A = age in years

Men: BMR=66.47+ (13.75 x W) + (5.0 x H) – (6.75 x A)

Women: BMR=665.09 + (9.56 x W) + (1.84 x H) – (4.67 x A)

**For me: 1402 cals**

**(2) Nancy Clark’s Food Guide for Marathoners **says that “to estimate your Resting Metabolic Rate (RMR), that is, the amount of of calories you need to simply breath, pump blood and be alive… Multiply your weight (or a good weight for your body) by 10 cals per pound (22 cals per kg)” For me, this is 1260-1300 kcals. Then add more calories for daily activity, eg 30-40% more if you are sedentary during the day or 60-70% more if you are very active. This does not include your run. If you run, you add another 100 kcal (on average, depending on your weight) for each mile. So your equation would look like this:

RMR + Daily Activity + Running kcals = Total Calories

1260 + 378 + _____ = 1638 kcal (+ whatever extra running cals. See below)

Nancy also says that to if you wish to lose weight, to target 80-90% of your total calorie needs.

**(3) Runningforfitness.com : **

First, calculate your basic calorie need:

Age | Men | Women |

10 – 18 | 17.5 x W + 651 | 12.2 x W (kg) + 746 |

19 – 30 | 15.3 x W + 679 | 14.7 x W (kg) + 496 |

31 – 60 | 11.6 x W + 879 | 8.7 x W (kg) + 829 |

Eg: I weigh 56kg, and I am a 29 year old female, so my resting metabolic requirement is: (14.7 x 56) + 496 = 1319 calories per day.

Then you multiply this according to how active you are during the day.

Acitivity | Multiplier | Description |

Sedentary | 1.4 | Little physical exertion during the day |

Moderately active | 1.7 | eg regularly walking during the day |

Very active | 2.0 | eg physically demanding work such as farming |

Eg: I’m mostly sedentary, because I have a sedentary job so I multiply by 1.4 x 1319 = 1846 calories per day. Then you add in your running cals (see below)

**(4) **I attended a **seminar** hosted by my triathlon club, where we were told that human beings need between 30-45 kcal per kg of lean body mass (LBM) or fat free mass (FFM) every day in order for the body to carry out its basic minimum functions. LBM = your overall weight – estimated body fat. For me, this works out as between **1395 kca**l (30 kcal/ kg of LBM) and **2092 kcal** (45 kcal/ kg of LBM). Now, if you’re like me in Weight Watchers or are otherwise trying to lose weight, then you’ll probably be just below that line – I say JUST below that line because it is so important that if you are trying to lose weight that you do so SLOWLY and SAFELY. Your body needs you to give it what it needs in order to carry out its basic functions – like transporting blood, helping your organs to do their thing, etc.

** [Sidenote: RMR v BMR. What’s the difference? **The only difference between these two measurements is that when properly conducted, the latter test is taken in a darkened room upon waking after 8 hours of sleep and 12 hours of fasting and with the subject resting in a reclined position. Whereas RMR measurements are typically taken under less restricted conditions and do not require that the subject spend the night sleeping in the test facility prior to testing. So the BMR calculation is likely to be more accurate.]

Stay with me, we’re nearly there!

Now, **the running part. **I ran 10 miles today. *Runner’s World * tells me that I burned 987 kcals, *Mapmyrun.com *tells me that I burned 1036 kcals and my *Garmin *tells me that I burned 984 kcals. Seen as we’re working out the minimum that your body needs, I’ll run with the lowest figure – 984 kcals. This means that my body used an extra 984 kcals of energy today than it would’ve done had I not ran today. That’s 984 kcals that my body is now short of to do its ordinary day-to-day work.

**Put it all together: **

**Ideal:** My body needs 1395 -2092 calories to perform its basic functions and maintain my weight. It needs a further 984 calories which were lost during my 10 mile run. Therefore, the maths say (whichever calculation you use) that I should consume 2379-3076 calories today. If you’re safely trying to lose weight at the moment (circa 1200 kcal), the maths still say you should be consuming 2184 calories on this day.

**Actual:** Consumed 1203 calories.

**Results: **I consumed far less calories on this day than I was supposed to according to the biology maths.

**Conclusions: **I’m assuming that the mathematical base which I used for all this is correct and accurate but I’m neither a scientist nor a nutritionist so there’s every possibility that my sums are wrong. What I am is an amateur runner with an interest is nutrition who is trying to work out from the mass of information out there what and how much I should be eating day to day.

As I found out when putting this post together, calculating calories and nutritional breakdown TAKES AN AGE and is a CHORE and it’s no wonder I often don’t know how many calories I’m taking in on a normal day if it takes so much effort to work it all out. And this is probably the case for most people, who, if they are anything like me – a runner who wants to keep their weight low/stay where they are, are likely to underestimate the caloric demands of their body day in, day out. If this is the case, then most runners are probably underfed and undernourished.

It doesn’t help either, the fact that there is such a variation between all of the different sources. What they have in common is that the basic minimum calorie intake for someone of my age, weight and height is approximately the same, or at least not radically different. Bodybuilding: 1402; Nancy Clark 1260; Runningforfitness.com 1319; and my seminar, 1395 kcals. Where they differ, is the inclusion of a “daily activity” addition, outside of your running/other activity addition. Some have em, others don’t. It’s confusing.

**Am I Getting Enough? **In answer to my question, no I am quite clearly not getting enough.

**What can I learn from all this mumbo jumbo? **I need to make a conscious effort to consume more energy on days when I run so that my body has enough energy to get me through my runs; get a good, solid repair and recovery underway afterwards; and go about its ordinary daily business. Starting tomorrow, I have a 12 mile medium-long run in the morning and am ready to up my game 🙂

My plan over the next few weeks is to up my level of calories and if any of the above calculations are correct, then my weight should remain the same. I’m not sure if I can hack counting calories because frankly, it’s beyond tedious, but I plan to run up a few sample days for the purpose of comparison and in the name of science!

In Part Two of this Eating the Burn series, I will be looking at energy breakdown and examining *what *I should be eating as a runner.

**Do you calculate your daily energy requirements as a runner or when you’re in training? Have you a go-to system that makes it easier or faster? Do you find all this calculation tiresome?**

What a great post! You did a good job of breaking it all down. Interesting to see the results of your calculations and how are you did not get enough calories that day. Personally, I probably would not have that problem as when I do long runs I can eat all the things. 🙂 I’m usually not one for counting calories but it was interesting to read this.

LikeLiked by 1 person

It’s fascinating when you break it all down to science and math but there’s no way I’d be able to do that every day. It’s just so tedious that I think I’d crack up! Good to know though.

LikeLike