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Note the energy Intake (kcal) and fat, carbohydrate (CHO) and protein (grams and kcal) in table 1 below. This will be athe bottom of the screen on the website, but you will need to click ‘Nutrition’ at the bottom of the screen on the App.

Table 1. Macronutrient intake over 1 day

 Energy Intake (kcal) Fat (g) Fat (kcal)* CHO (g) CHO (kcal)* Protein (g) Protein (kcal)*

*kcal from each macronutrient can be calculated using the ‘Atwater General Factors’ – fat (g) x 9, CHO (g) x 4 and protein (g) x 4.

Step 4. Calculate the % of total energy intake from each macronutrient.

Table 2. Relative contribution of different macronutrients to total energy intake

 Macronutrient % of kcal intake Fat CHO Protein

% of total intake is calculated as – (macronutrient kcal/energy intake kcal) x 100

Calculating Energy Expenditure, Energy Balance and Energy Availability

Step 1. Calculate your resting metabolic rate using the Harris-Benedict equation (1919) below:

Females: RMR (kcal·day-1) = 655 + (9.6 x mass [kg]) + (1.85 x ht [cm]) – (4.68 x age)

Males: RMR (kcal·day-1) = 66 + (13.8 x mass [kg]) + (5 x ht [cm]) – (6.8 x age)

Table 3. Estimated RMR per day, hour and minute.

 kcal·day-1 kcal·h-1 kcal·min-1 Estimated Resting Metabolic Rate

Step 2. Calculate the energy expended during physical activity by multiplying the RMR (above) with the appropriate MET per unit time as identified in the table below.

Table 4. Physical activity factor for various daily activities (Manore & Thompson, 2006)

 Activity Grade Examples Activity Factor (per unit time) Resting Sleeping, reclining RMR x 1 Very light Seated and standing activities, driving, cooking RMR x 1.5 Light Slow walking, cleaning, table tennis, recreational tennis RMR x 2.5 Moderate Fast walking, carrying a load, tennis, slow cycling RMR 4 (3-5) Strenuous Jogging/running, fast tennis, moderate swimming, weight training, walking up hill with a load, soccer RMR x 7 (5-9) Very Strenuous Race pace swimming, rowing, cycling or running (10-15 km·h-1) RMR x 10 (7-13)

Energy expenditure in physical activity = ________________ kcal

Step 3. Calculate your daily energy expenditure by adding the kcal expended during any physical activity and your RMR (kcal·day-1). Compare it to your energy intake, calculating the energy difference (kcal·day-1) and commenting on whether you are in positive or negative energy balance.

Table 5. Energy balance based on difference on total daily energy expenditure and intake (kcal·day-1).

 Total daily energy expenditure (kcal·day-1) Total daily energy intake (kcal·day-1) Energy difference (kcal·day-1) Energy balance

Questions

• Why might your food diary be an inaccurate representation of you daily energy intake?

• What are the implications of your energy balance for your body weight, health and athletic performance?

This is an extra task, in addition to the Energy Balance Workshop task, which will allow you to estimate an athlete’s energy availability (kcal·kg FFM-1·day-1).

The first stage of this assessment would include a measurement of the athlete’s body composition. This is because energy availability is expressed in kcal·kg FFM-1. For the purpose of today, we will assume a body fat of 15% for males, and 20% for females (this should be measured in practice!). With these assumptions, calculate the following variables:

• Your fat-free mass (FFM, kg) – This is calculated as:

(body mass/100) x 85 or 80

(the 85 or 80 here refers to the percentage of the body that is FFM. So, if we assume you have 15% body fat, then 85% is FFM)

• Your energy intake per kg FFM (kcal·FFM·day-1) – This is calculated as (energy intake/FFM)
• Your energy expenditure in physical activity per kg FFM (kcal·FFM·day-1) – This is calculated as (energy expenditure in physical activity/FFM)
• Your energy availability (kcal·FFM·day-1) – This is calculated as (energy intake per kg FFM – Your energy expenditure in physical activity per kg FFM).

Table 6. Energy availability

 FFM (kg) Energy intake (kcal·FFM·day-1) Energy expenditure in physical activity (kcal·FFM·day-1) Energy availability (kcal·FFM·day-1)

Questions

• What is your energy availability in comparison to recommended guidelines? What are the implications of low energy availability?