At 5 am I was up today to drive an hour for what I thought was a 25 mile bike ride. I was feeling good, and that soon became a 40 mile ride. After, I checked my HRM and I had burned about 2000 calories. It got me thinking about the lack of or overuse of calories in peoples diets who are in training. I have a great formula that will hopefully shed some light on the subject.
Your necessary daily caloric intake depends on 4 factors. Basal metabolic rate, physical activity, type of diet, and fat %. This formula is a great help in figuring out how many calories you need based on your personal variable factors.
Caloric intake(CI)=step 1+ step 2+ step 3
Step 1) Calculate BMR:
For Female: BMR=Weight X 11=#calories
For Male: BMR=Weight X 12=# calories
This number will be used in the two other steps and at the end.
Step 2) For this step you have to use a multiplier. Since none of use are sedentary I will just list for active and very active lifestyles. Active is categorized as 3+ hours of exercise per week, very active is 8+. You can only choose one multiplier based on whether your active or very active.
If active, multiply step 1 calories by .50. If very active, multiply calories from step 1 by .75. Save the number you get after calculating.
Step 3) This step calculates how many calories your body uses digesting your food. For a high carb diet, multiply calories from step 1 by .10. If your diet is high fat, multiply calories from step 1 by .05.
Step 4) Add the calories from each step to get your total daily CI. Since these figures are based on “average” fat percentages, the last step is to adjust for your actual body fat %. The average for a female is 22% and for a male is 18%. Subtract the average body fat % for your gender from your actual body fat %. Then subtract that number from 100% and get a % number. The percentage number is multiplied by your CI and the number you come up with is your adjusted CI based on your body fat %. This is the estimated number of calories your body needs to consume to gain muscle and burn fat.
Heres an example based on my statistics: Male/14% body fat/High carb diet/180 pounds/very active
Step 1=2160 calories+ Step 2= 1620 calories+ Step 3=216 calories Total=3996 calories
Adjust for personal body fat: 100%-(14%-18%)=104%
104=1.04 3996(1.04)= 4155 calories
This means I need to consume 4155 calories daily to continue to build muscle and lose fat. Of course no formula is perfect but this is very good for estimation. Another more exact approach is to use a HRM every workout and add the total used calories in a day. Then, add only step 1 and step 3, adjust for your actual body fat % and finally add to that number the total calories used from your daily workouts.
I hope this formula helps. I used to consume a lot less than what I actually needed. It is always interesting to see how your body consumes the total fuel you put in your tank.