1. National Diploma Sport (Performance & Excellence)
Sport Nutrition

2. Aims and Objectives
Know energy intake and expenditure in sports performance
Energy:
measures (calories, joules, kilocalories, kilojoules)
sources, eg fats, carbohydrates, proteins
measuring requirements, eg body composition, lean body mass, percentage body fat (skinfold analyses, bioelectrical impedance analysis, hydrodensitometry); body weight
calorimetry (direct, indirect)
Energy balance:
Basal metabolism
Age
Gender
Climate
Physical activity

3. Assessment Criteria
P4 describe energy balance and its importance in relation to sports performance
M2 explain the importance of energy balance in relation to sports performance
D1 analyse the effects of energy balance on sports performance

4. Units of energy measurement
1 calorie = energy (heat) required to raise the temperature of 1g of water by 1oC (from oC).
Very small unit
Converted to kcal (1000 calories).
Energy required to raise 1kg water 1oC
1 kcal = 4.2 kJ
1oC
1 g E
1 joule (J) = energy expended when 1 kg is moved 1 m by a 1 N force (work done).
Usually measured in kJ or MJ.

5. Burn those calories!! Mars bar ~ 295 Kcal
How long would it take to use up this calorie content?
For every 1 litre of O2 used we expend ~ 5 kcal energy
Rest :
(VO2 = 0.25 l/min) = 1.25 kcal/min
= 3 hrs 56 min!!
High intensity exercise (~80% VO2max)
(VO2 = 3 l/min) = 15 kcal/min
= 20 mins!!

6. Components of Daily Energy Expenditure
Thermic effect of feeding
Energy expenditure of physical activity
Resting energy expenditure
17% 8% 8%
32%
75%
60%
Sedentary Person (1800 kcal/d)
Physically Active Person (2200 kcal/d)
Segal KR et al. Am J Clin Nutr. 1984;40:
Slide Source:

7. Estimating Energy Requirements
BMR (Basal Metabolic Rate) – this is the minimal calorie requirement needed to sustain life in a resting individual
You would burn this amount of energy if you slept all day or rested in bed for 24 hours
A number of factors can affect BMR
Some factors speed your BMR up so you are burning more calories per day to stay alive
Others slow your metabolism down so you need to eat fewer calories to stay alive
Make a list of what you think the different factors are, giving reasons.

8. Factors affecting BMR Age Body size Growth Body Composition Fever
Stress
Environmental temperature
Fasting
Thyroxin

9. Estimating energy and macronutrient requirements
To estimate energy requirements you need to calculate your Basal Metabolic Requirements (BMR)
This is measured in kilocalories per day
for a 10-17yr old male BMR = 17.7W(weight in Kg’s) + 657

10. BMR Males 10-17yrs BMR=17.7W+657 18-29yrs BMR=15.1W+692
Females
10-17yrs BMR=13.4W+692
18-29yrs BMR=14.8W+487
30-59yrs BMR= 8.3W+846
Schofield etal, 1985

11. Estimating energy and macronutrient requirements
You also need to consider your level of physical activity and training
Simplest method of estimating your total energy requirements:
Multiplying BMR by PAL (physical activity level)

12. PAL
To calculate PAL you have to make assumptions about the energy demands of your occupational and non-occupational activity levels

13. Occupational Activity
Pal for three levels each of occupational and non-occupational activity
Occupational Activity
Non-occupational activity
Light
Moderate
Heavy M F
Non-active
1.4
1.6
1.5
1.7
Moderately active
1.8
Very active
1.9

14. Alcohol Concentrated source of energy Produces 7kilocalories per gram
This energy is not available to the working muscles
Excess energy from alcohol is stored as fat
Current safe limits recommended by Health Education Authority – 3-4 units/day for men, up to 2-3 units /day for women

15. Energy needs and energy balance
Energy balance is when the amount of energy taken in = the amount of energy used (output)
4 major components to energy output
Resting metabolic rate
Dietary thermogenesis
Physical activity
Adaptive thermogenesis

16. Energy needs and energy balance
Basal Metabolic Rate (BMR) account for 60-75% of total energy output
BMR will depend on body composition e.g. gains in muscle mass will increase BMR
Sex, age and genetic background also have a bearing
Dieting (low energy intake) can lead to a reduced BMR

17. Energy needs and energy balance
Dietary Thermogenesis (DT) – energy expended above BMR – digestion, absorption, transportation and storage of food
Influenced by calorie content and composition of meals eaten
High energy intake and regular eating pattern help maintain higher rates of DT

18. Energy needs and energy balance
Physical Activity (PA) – most variable component of energy expenditure
This is additional expenditure above BMR and DT
How much will depend on level of activity, lifestyle, how often and how energetically and for how long we participate in sport and exercise

19. Energy needs and energy balance
Adaptive Thermogenesis (AT) is energy expenditure due to environmental or physiological stresses placed on the body
Changes in temperature - shivering
Stress that causes anxiety or fidgeting

20. Energy needs and energy balance
When energy intake is greater than output
this is known as
Positive Energy Balance –
Weight is gained
When energy intake is less than output, we
use up fat stores, this is known as
Negative Energy Balance
Weight is lost

21. Energy needs and energy balance
Sportspeople are concerned about maintaining or attaining an optimal body weight
Some sports set weight restrictions e.g.
Body building
Boxing
Horse racing
Martial arts
Rowing

22. Energy needs and energy balance
Some sports benefit from increased body size e.g. rugby or American football
Other sports need a low body weight which may be below natural weight – weight-controlled sports e.g.
Distance running
Gymnastics
Diving

23. Energy needs and energy balance
To maintain a low body weight or reduce weight whilst also maintaining a nutritionally suitable diet inappropriate weight loss practices can be found e.g.
Fasting
Skipping meals
Laxative abuse
Binging
Purging
Intentional dehydration – use of sweat-suits or saunas

24. International Consensus Conference, Lausanne, 1991
Diet significantly influences athletic performance. An adequate diet in terms of quantity and quality, before, during and after training and competition will maximise performance
International Consensus Conference, Lausanne, 1991

25. Nutrition for athletic performance
Daily eating- the training diet
Special practices- competition diet
The competition diet may include nutrition in the days prior to competition and also during the event

26. Different sports have different nutritional requirements
Endurance Intermittent Sprint!

27. All the essential nutrients are contained in the foods that make up a varied diet
Carbohydrate
Fat
Protein
Vitamins
Minerals
Water
Fibre

28. Recommended Balance of Nutrients
w 55% to 60% carbohydrate (CHO)
Less than 30% fat (less than 10% saturated)
10% to 15% protein (RDA 0.8 g/kg body mass)
Energy needs:
e.g. woman of 58 kg with total energy need per day of 2000 kcal (Total MR = BMR + activity)
As much as 1400 kcal are required for BMR supporting vital body processes (70% of total energy needs)
Assuming she consumes 2000 kcal per day. At ~4 Kcal per g of CHO (55% of kcal intake) or protein (15% kcal intake) how many g of each nutrient will she consume
Is she consuming the required RDA for protein?

30. Requirement for some nutrients is increased by heavy exercise
BUT
High nutrient intakes can be achieved from the diet if:
Energy intake is moderate to high
A variety of foods make up the base of the diet

31. Special nutritional needs for training
Athletes think?
Extra protein?
Extra vitamins?

32. Research evidence Major concerns are Appropriate energy intake
High carbohydrate intake
High water intake
Moderate concerns are
Adequate protein
Adequate vitamins and minerals

33. Energy intake- How much is enough?
Depends upon
Body mass
Training/competition load- FITT principle
Growth needs
Individual characteristics
Need to lose body fat
Need to gain weight

34. Energy requirements in extreme endurance events
Limited reports on dietary intake and expenditure in elite athletes during endurance events
Marathon runners during a 20 d road race averaging 28 km/d. Estimated energy intake was 20.2 MJ/d (4844 kcal!). 61% CHO, 27% fat, 12% protein
(Dressendorfer et al JAMA, 247, )

35. Energy requirements in Parachute Regiment Recruits
Daily energy expenditure averaged 19 MJ.d-1 (4500 kcal. d-1) during the 20 week training course.
Only a small energy deficit was found (~0.1 MJ.d-1) in troops who completed the course
(Wilkinson et al MSSE, 36, S261)

36. Energy requirements in Elite Swimmers
N=5 females, swimming ~17.5 km.d-1 (5-6 h.d-1)
Energy expenditure on rest day was 7.7 MJ.d-1 (1840 kcal. d-1)
Energy expenditure on training day was 23.4 MJ.d-1 (5600 kcal. d-1)
Energy intake averaged 13 MJ.d-1 (3100 kcal. d-1)
-ve energy balance of 43% on training days
(Trappe et al MSSE, 29, 950-4)

37. Tour De France 4000 km racing 21 stages ~120 h total time One rest day
Mountain passes
Reaching altitude of 2700 m

38. Flat stages 8-10 flat stages ~200 km, average 45-50 km/h
In peleton ~ 200 riders
Reduction of air resistance ~40% saving in energy!

39. 30 Mountain Passes

40. Time Trials
Normally 3 TT ranging from km
Individual and team TT

41. Food intake and energy expenditure during Tour de France (n =4)
Energy Intake
Overall mean
MJ/day
25.4 ± 1.4
(~6100 Kcal)
24.7 ± 2.4
Highest
32.7 ± 1.6
(~7850 Kcal)
32.4 ± 4.4
Resting day
12.9 ± 0.9
(~3100 Kcal)
16.1 ± 3.9
NB. RDA young adults doing light work is MJ/day
Saris et al Int J Sports Med, 10, S26-31

42. Characteristics of 4 cyclists before and after Tour de France
Subject
Maximal O2 uptake
(ml/kg/min
Mass
Before
(kg)
After
Body fat
(%) 1
75.2
71.6
71.5
13.2 2
79.0
74.0
11.1
10.6 3
80.8
61.4
61.9
9.8
10.0 4
82.4
68.7
68.3
12.1
11.8
Mean
79.4
69.2
68.9
11.6
11.4
Saris et al Int J Sports Med, 10, S26-31

43. Saris et al. 1989. Int J Sports Med, 10, S26-31
Mean daily intake of energy and nutrients from food and supplements and relative % intake on and off the bike during Tour de France (n =5)
Mean
% on the bike
Energy (MJ)
24.3 49
CHO simple (g)
463 61
CHO complex (g)
386 55
Fat (g)
147 39
Protein (g)
217 35
Water (l)
6.7
Saris et al Int J Sports Med, 10, S26-31

44. HHHHHhhhhmmm CAKE!