A lot of individual variables determine calorie needs for an athlete (size, gender, type of sport, training cycle, etc.), which means it can be a trial and error adventure. You’ll want to estimate a number of calories, or amounts of food to eat in a meal plan, and then tweak it up or down to find your level. To begin, use the formula below to get a ballpark figure of daily calories that you need. It takes into account your Resting Energy Expenditure (REE), the calories burned at rest, and your activity level, the calories you burn by intentional movement.
Formula for calorie estimation:
REE = 1 calorie x kg (kilograms) body weight (kg = weight in pounds divided by 2.2) x 24 hours
Then multiply your REE calories by the appropriate activity level:
- Very Light = Extremely sedentary (e.g. bedrest): 1.2 – 1.3
- Light = No planned activity, mostly officework: 1.4 – 1.6
- Moderate = Walking, stair-climbing during the day: 1.6 – 1.8
- Heavy = Planned, vigorous activity: 1.9 – 2.1
Example: A 150-pound person that exercises vigorously:
150 lbs. / 2.2 (lbs. in a kg) = 68 kg
1 calorie x 68 kg x 24 hours = 1632 calories at rest (REE)
1632 x 1.9 activity factor = 3100 calories required to maintain current weight
In this instance, 3100 calories would be required to maintain current weight, given your activity level. Remember, there are many variables that influence the calorie level that is right for you. This is a very gross estimate, and cannot take into account individual metabolic rates, variable energy expenditure on different days, fidgeting, differing energy expenditure rates for various individuals even if most other variables are similar, etc. And this is only one of many formulas available, some eliciting widely varying amounts (trial and error adventure, remember?).
Most people that have been doing similar work and exercise regimens for a period of time have a pretty good idea of how much and what they need to eat to obtain the calories required to maintain their weight and energy. But for those that may need a starting place, or whose needs change often because of varying training regimens, this represents one method that may be of help.