BS371 NUTRITION AND DRUGS IN SPORT AND EXERCISE Anna Wittekind.

BS371 BS371 NUTRITION AND DRUGSNUTRITION AND DRUGSIN IN SPORT AND EXERCISE SPORT AND EXERCISE

Anna WittekindAnna Wittekind

OverviewOverview

How the lectures are organised How the lectures are organised Read relevant lecture in BS153Read relevant lecture in BS153

Module GuideModule Guide Reading listReading list Assignment – next lectureAssignment – next lecture ExamsExams

The athlete’s dietThe athlete’s diet What are the special nutritional needs What are the special nutritional needs

of athletes in training?of athletes in training?• CarbohydrateCarbohydrate 60-70%60-70%• LipidLipid 20-25%20-25% • ProteinProtein 10-15%10-15%

What should they be eating?What should they be eating?

• ACSM Position Stand (2000) - Nutrition and ACSM Position Stand (2000) - Nutrition and athletic performance. athletic performance. http://www.acsm-msse.org/pt/pt-core/tehttp://www.acsm-msse.org/pt/pt-core/te

mplate-journal/msse/media/1200.pdfmplate-journal/msse/media/1200.pdf

Burke, L. (2007) IAAf Concensus on Burke, L. (2007) IAAf Concensus on Nutrition for Athletes: Updated Guidelines. Nutrition for Athletes: Updated Guidelines. IJSNEM IJSNEM 17 (4): 17 (4):

Energy requirementsEnergy requirements During times of high-intensity training, adequate During times of high-intensity training, adequate

energy needs to be consumed toenergy needs to be consumed to maintain body weight, maintain body weight, maximize the training effects, and maximize the training effects, and maintain health. maintain health.

Low-energy intakes can result in Low-energy intakes can result in loss of muscle mass, loss of muscle mass, menstrual dysfunction, menstrual dysfunction, loss or failure to gain bone density, and loss or failure to gain bone density, and increased risk of fatigue, injury, and illness. increased risk of fatigue, injury, and illness.

(ACSM Position Stand)(ACSM Position Stand)

Do athletes achieve the Do athletes achieve the guidelines?guidelines?

QuestionsQuestions

Measuring energy Measuring energy expenditureexpenditure

TDEE = RMR (REE) + TEF + TEA TDEE = RMR (REE) + TEF + TEA + any additional costs (growth, pregnancy, + any additional costs (growth, pregnancy,

lactation)lactation) e.g. 70 kg male runner e.g. 70 kg male runner

runs 10 miles per day at a 6-min/mile runs 10 miles per day at a 6-min/mile Requires ~ 1,074 kcal per day for running (17.9 Requires ~ 1,074 kcal per day for running (17.9

kcal/min) +kcal/min) + energy cost of normal daily activities (2900 kcals)energy cost of normal daily activities (2900 kcals) Thus, this athlete would need approximately 3,974 Thus, this athlete would need approximately 3,974

kcal.dkcal.d-1-1.. Tour de France ~7,000 kcal.dTour de France ~7,000 kcal.d-1-1

But….But….

Energy in vs Energy outEnergy in vs Energy out

These foods provide 400kJ of energy:

Energy in vs Energy outNumber of

minutes to use up 400kJ of energy:

How do we measure energy How do we measure energy expenditure?expenditure?

Indirect calorimetryIndirect calorimetry DLWDLW Factorial method using prediction equations Factorial method using prediction equations

based on rmr + energy cost of daily based on rmr + energy cost of daily activitiesactivities e.g.e.g. Cunningham (1980) Cunningham (1980)

RMR = 500 + 22(lbm)RMR = 500 + 22(lbm)

Harris Benedict (1919)Harris Benedict (1919) E.g. Males RMR = 66.47 + 13.75 (bm) + 5(ht) – 6.76 E.g. Males RMR = 66.47 + 13.75 (bm) + 5(ht) – 6.76

(age)(age)

How do we measure energy How do we measure energy expenditure?expenditure?

RMR x activity factor (Manore and RMR x activity factor (Manore and Thompson, 2006)Thompson, 2006) e.g.e.g. Resting – RMR x 1Resting – RMR x 1 Moderate – walking 3.5 – 4 mph, slow Moderate – walking 3.5 – 4 mph, slow

cycling…. RMR x 4cycling…. RMR x 4 Very strenuous – race pace swimming, Very strenuous – race pace swimming,

cycling …… RMR x 10cycling …… RMR x 10

Measuring dietary intakeMeasuring dietary intake

Dietary historyDietary history Dietary recallDietary recall FFQFFQ Food record/diaryFood record/diary

Energy balance?Energy balance?

Many situations of apparent energy Many situations of apparent energy imbalanceimbalance Body mass/compositionBody mass/composition Does energy deficit reflectDoes energy deficit reflect

Undereating and/orUndereating and/or Underrecording Underrecording

Energy availabilityEnergy availability

Can energy intake support health and Can energy intake support health and performance?performance?

= dietary energy available to the body = dietary energy available to the body after energy cost of daily exercise taken after energy cost of daily exercise taken into account (Loucks 2004)into account (Loucks 2004) 45 kcal.kg45 kcal.kg-1-1 lbm.d lbm.d-1-1

<30 kcal.kg<30 kcal.kg-1-1 lbm.d lbm.d-1-1 -ve effects on metabolism and menstrual function -ve effects on metabolism and menstrual function

(Loucks and Thuma, 2003), (Loucks and Thuma, 2003), ↓ ↓ resorption/formation bone (Ihle and Loucks, 2004)resorption/formation bone (Ihle and Loucks, 2004) ↓↓ metabolic/sexual hormones metabolic/sexual hormones ♂(Friedl et al., 2000)♂(Friedl et al., 2000)