Know your daily energy requirements
The cornerstone of any self-respecting athlete, daily energy requirements tell you how many calories your body will need per day to :
- Ensure its vital functions
- Enable you to take part in physical and sporting activities
- Keep you going at work
- Get you closer to your sporting goal and achieve results
But calculating it depends on many parameters, including your age and sex, as well as your lifestyle and other more personal factors, such as genetics. We tell you more about this formula and give you our recommendations.
Energy balance: how many calories do I consume per day and how much do I spend?
Definition
As the basis of any sports program, it's essential to know your energy balance, whatever your objective (to gain weight, lose weight or even maintain your body weight), so you know how many calories you need to consume per day to get closer to your goal.
This calculates your nutritional intake and energy expenditure over the course of the day, and thus determines your daily energy requirements. There are 3 possible results, on which you can base your eating plan, so that it corresponds as closely as possible to your needs:
- A positive energy balance means you consume more calories than you burn off. => You gain weight.
- A negative energy balance means you burn more calories than you consume => you lose weight.
- A balanced energy balance means that your calorie consumption is equivalent to your calorie expenditure. => Your weight remains stable.
In theory, this sounds simple enough, but in practice, it depends on many other factors, depending on the individual, which can also vary over time for the same person, depending on endogenous and exogenous circumstances. The criteria taken into account must be inherent to the individual's specificities, lifestyle and objective, among them:
- Gender
- Age
- Body weight
- Basic metabolism (morphotype)
- Expenditure (professional & sporting)
- Objective(s) (mass gain, lean, muscle gain...)
Whatever your training program, the number of repetitions, the loads added, and even the quantity of food supplements consumed, your results will only be satisfactory if your dietary base is known and mastered. In fact, more and more sports nutrition professionals estimate that it accounts for 70% of results. You'll need to ensure that you're getting the right calories and nutrients, at the right time, in the right quantities, without being excessive.
How do you calculate and define your basal metabolic rate?
That is, the number of calories your body needs to maintain your vital functions at rest (such as heartbeat, breathing, digestion, brain activity, etc.) These functions already expend a good proportion of the calories we consume, without us even realizing it.
In 1990, 6 American researchers, including Mark Mifflin and Sachiko St Jeor, developed a formula - now the most reliable - for estimating energy requirements based on an individual's basal metabolic rate. These are determined according to 3 simple criteria: age, weight and height.
What is the formula for calculating daily energy requirements for adult men and women?
Mifflin St Jeor formula: (10 x weight) + (6.25 x height) - (5 x age) + or - sex coefficient* * men + 5 x age
- men + 5
- women - 161
Example for Cyril, an adult male aged 35, weighing 90 kg, measuring 180 cm:
(10 x 90 kg = 900) + (6.25 x 180 cm = 1125) - (5 x 35 years = 175) + 5 = 1855 kCal
Example for Clara, an adult woman aged 25, weighing 60 kg, measuring 170 cm:
(10 x 60 kg = 600) + (6.25 x 170 cm = 1065.5) - (5 x 25 years = 125) - 161 = 1,379.5 kCal
This formula is the one that gives you the closest idea to reality of the number of calories your body needs to perform its vital functions. Then you need to add your daily expenditure, linked to your professional and sporting activities.
Other factors can influence calorie expenditure, such as stress, anxiety or lack of sleep. But we have little control over these parameters, and they are unfortunately difficult to take into account.
How do you define your calorie expenditure?
1. Sports activities
Energy expenditure, linked to physical activity, will obviously have a major influence on our daily calorie requirements. You'll need to take the figure corresponding to your MB (basic metabolism) and multiply it by a coefficient related to the level of intensity and regularity of your activities.
How do you calculate your sports activity coefficient?
MB x 1,1 - Sedentary, no physical activity
MB x 1.2 - Light physical activity once or twice a week
MB x 1.3 - Moderate physical activity three to four times a week
MB x 1.4 - Daily moderate physical activity
MB x 1.5 - Intense physical activity 5 to 7 times a week
MB x Sports activity coefficient = MT (Total metabolism)
2. Professional activities
Having defined energy expenditure due to physical activity, it is important to take into account another parameter to further refine the estimation of energy requirements. These are linked to professional activities, since a person who carries out a less active activity, behind a computer, for example, will not have the same caloric expenditure as a letter carrier, bricklayer or baker.
We'll therefore try to find our overall metabolism by multiplying our TM between 0.0 and 0.02; this will give us the sum of energy requirements for all activities (physical and professional).
How do you calculate your professional activity coefficient?
MT x 0.0 - Sedentary professional activity (desk, sitting)
MT x 0.1 - Active professional activity (delivery, standing)
MT x 0.2 - Very active occupation (site worker, road worker)
We'll keep the same examples, but refine them so that you can see how important it is not to forget any parameter when calculating your daily energy requirements.
Example for Cyril, a 35-year-old adult male, 90 kg, 180 cm tall, letter carrier, who trains 6 times a week intensively:
(10 x 90 kg = 900) + (6.25 x 180 cm = 1125) - (5 x 35 years = 175) + 5 = 1 855 kCal
1,855 kCal X (1.5 + 0.2) = 3,153.5 kCal/day (MG)
Example for Clara, an adult woman aged 25, 60 kg, 170 cm tall, marketing manager, who practices pilates 1 hour a week:
(10 x 60 kg = 600) + (6.25 x 170 cm = 1065.5) - (5 x 25 years = 125) - 161 = 1,379.5 kCal
1,379.5 kCal x (1.2 + 0.0) = 1,654.8 kCal/day (MG)
This method is the closest to reality, on average, even if it remains a recommendation. In fact, there are other parameters, this time genetic and intrinsic to each individual, which can cause these figures to vary. First of all, there's the metabolic rate, which is specific to each individual. This factor is linked to genetics and directly influences the speed at which your body burns calories, depending on your morphotype. Taking this parameter into account will enable you to further refine your calorie expenditure base, which is already quite precise.
What are the different morphotypes?
There are three different morphotypes, regardless of gender, representing three types of physique:
- Ectomorph: These people generally have difficulty gaining weight. They are thin-boned and have a rather slim, lanky physique.
- Mesomorph: These people have a body that adapts according to what they eat, and a rather athletic physique.
- Endomorph: Unlike ectomorphs, these people find it harder to lose weight. They have strong bones and a rather stocky physique.
It's important to take this parameter into account when calculating your daily energy requirements, to get even closer to your body's real needs.
How to calculate your morphotype coefficient?
MG x 1.2 - Ectomorph
MG x 0.0 - Mesomorphic
MG x 0.9 - Endomorph
MG x morphotype coefficient = Total energy balance (BET)
Once again, let's take the example of Cyril and Clara:
Cyril is endomorphic: 3,153.5 x 0.9 =2,838.15 kCal/day
Clara is ectomorphic: 1,654.8 x 1.2 =1,985.76 kCal/day
How can you adapt your calories and nutritional intake to your goal, and what are your daily energy requirements?
If you're a bodybuilder, you probably have one of these two goals in mind: muscle gain or fat loss, or you've even probably already had both goals, at different times. We specify, at different times, because it won't be possible to achieve this double transformation by following just one eating plan. There are rules to ensure that your efforts are not in vain, and even maximize your results.
I want to build muscle. How many kilocalories should I consume per day?
If your goal is to build muscle mass, then your total energy balance needs to be positive by 15%, in short, you still need to multiply your BET by 15% so that your body has enough resources to feed and build your muscle.
For example:
Clara wants to build muscle: 1,985.76 - 15% = 2,283.624 kcal/day
I want to lose fat, how much kj should I ingest per day?
Conversely, to lose fat, your total energy balance will have to be negative by 15%. This will force the body to draw on its reserves, i.e. stored fat, to compensate for an energy expenditure greater than its intake, and thus trigger weight loss.
For example:
Cyril wants to lose fat: 3,153.5 - 15% = 2,855.49 kcal/day
Of course, knowing your daily energy requirements isn't the whole story, since you'll then need to look at micro and macro-nutrients (carbohydrates, proteins, lipids) and their distribution, as well as knowing how to target the calories that will really benefit your body's functioning. These are just recommendations, which you can then adjust. Diet has a big part to play, because without a healthy, balanced and adapted diet, you won't be allowing your body to develop properly, and above all, you'll see your goals slipping away...
In the meantime, grab a pen, a piece of paper and a calculator, and we'll give you a moment to determine your daily energy requirements based on all these parameters, so you can get closer to your goals! Once you've calculated your energy requirements, you can turn your attention to nutrition, and learn the best tips for improving your sporting performance (spoiler: protein, hydration and sleep are essential).