Calories to Burn
***8/26/14: Please refer to Math as a Fitness Professional and Nutrition Math for more up-to-date information on this topic.
Your client wants to lose 20 lbs in the next 15 weeks. Or maybe you have a client who wants to lose 25 lbs in the next 20 weeks. Where do you start? What caloric deficit do they need to achieve this goal? Are they burning calories by exercising as well?
(Remember, weight loss is when calories in < calories burned)
For those of you who have gotten through Chapter 4 – Nutrition – in ACE’s Essentials of Exercise Science for Fitness Professionals book, these questions may look familiar. For those of you who want to follow along at home, I’ll be referencing pages 210-211 in the Essentials book and looking specifically at questions 7 and 9.
Although we’re going to use questions 7 and 9 as examples, there are ideas here that apply outside this chapter. When faced with a question asking ‘what caloric deficit is needed”, many candidates first go looking for an easy equation that will solve the problem. When they don’t find one (because there isn’t a specific equation) the panic starts to set in.
But remember…when you start to panic, don’t forget to take a few deep breaths also. First, let’s look at question 7:
Your client would like to lose 20 pounds (9 kg) over the next 15 weeks. What daily caloric deficit is needed to achieve this goal?
Our client wants to lose pounds, and to do so we need to reduce her calories. So the first question is…how do pounds and calories relate? How many calories are in a pound? 3500kcal = 1pound (page 174 in Essentials)
1 lb = 3500kcal (remember, kcal is the same as calories, just shortened for ‘easy reading’)
20 lb = 70,000 kcal (we take 20 x 3500)
70,000kcal is what our client needs to burn, and she has 15 weeks to do so
70,000kcal / 15 weeks = 4666.667 kcal per week to reach her goal
But we want to know daily deficit so…
4666.667kcal / 7 days (7 days in a week) = 666.667 kcal per day, which you can round to 667 kcal/day
Got it? Understand how we got from the question to the answer? Great. But just when it all seems to make sense, question 9 throws in a curve ball:
Your client would like to lose 25 lbs (11.3kg) over the next 20 weeks. If he agrees to increase his physical-activity levels by 300 kcal per day, how many calories would he need to reduce from his daily intake to reach this goal?
You know where to start with this one, it isn’t any different from question 7. We have to find out what calorie deficit the client needs per day. (You’re on your own for this calculation)
Got that number? Okay, now remember that a calorie deficit comes about because we burn calories through exercise or we just don’t eat them. We know what calorie deficit/day the client needs…and we also know how much of this deficit is covered by physical activity.
(hint…635 kcal/day deficit – 300kcal burned through activity = 325 kcal reduced from daily intake of food)
What lessons do we take away from these examples? When you come across a question, particularly a math question, think about what you are being asked and what you know. Can you make any connections? This relates back to the understand rather than just memorize philosophy of the ACE exam.
Questions? Contact an ACE Education Consultant at 1-888-825-3636 x782.