Download presentation
Presentation is loading. Please wait.
Published byLucas Fletcher Modified over 8 years ago
1
Ex Nutr c3-energy1 Measuring energy expenditure Direct calorimetry Indirect calorimetry Douglas bag Breath-by-breath systems
2
Ex Nutr c3-energy2 Bomb calorimeter
3
Ex Nutr c3-energy3 Bomb calorimeter
4
Ex Nutr c3-energy4
5
5
6
6 Direct calorimetry chamber
7
Ex Nutr c3-energy7 Direct calorimetry chamber
8
Ex Nutr c3-energy8 Closed circuit method
9
Ex Nutr c3-energy9 Closed circuit method
10
Ex Nutr c3-energy10
11
Ex Nutr c3-energy11
12
Ex Nutr c3-energy12 Douglas bags
13
Ex Nutr c3-energy13
14
Ex Nutr c3-energy14 Indirect calorimetry and substrate utilization Assume protein is not important energy source In some extreme conditions, protein may provide up to 15% energy expenditure Correction for protein oxidation Protein oxidation estimated from nitrogen content in urine
15
Ex Nutr c3-energy15 Calculate CHO and fat oxidation rate using VO2 and VCO2 Assume protein oxidation is zero
16
Ex Nutr c3-energy16 Adjusted for protein oxidation
17
Ex Nutr c3-energy17 RER vs RQ Respiratory exchange ratio (RER, or R) measured at mouth does not always reflect oxidation process in cells (respiratory quotient, RQ) Hyperventilation: excess CO 2 expired Extra excretion of body CO 2 stores (HCO 3 - in extracellular fluid) Buffering of H+ H + + HCO 3 - > H 2 CO 3 < H 2 O + CO 2
18
Ex Nutr c3-energy18 Doubly labeled water Administration of bolus dose of 2 stable isotopes of water: 2 H 2 O, H 2 18 O 18 O lost in water and as C 18 O 2 2 H (deuterium 氘 ), 3 H(tritium 氚 ) lost in water alone Difference between 2 tracer excretion rates represents CO 2 production rate Unbiased measurement of free-living situation Relatively long-term (days, weeks) estimation of energy expenditure Also use H 13 CO 3 Equilibrium with body’s CO 2 pool
19
Ex Nutr c3-energy19
20
Ex Nutr c3-energy20 Muscle biopsy
21
Ex Nutr c3-energy21 Other methods in estimating EE Heart rate monitoring Require individual relationship between HR, VO2, EE Accelerometer 1, 2, or 3 axes Combine HR monitoring and accelerometer Activity records 24 hr, 1 week, or 1 month recall
22
Ex Nutr c3-energy22 Components of Energy Expenditure Total energy expenditure = Basal Metabolic Rate (BMR) + TEA+TEF+AT Basal metabolism: energy expanded during nonactive rest (just waking) Thermal Effect of Activity (TEA) Thermal Effect of Food (TEF): associated with consumption of food, digestive, absorption, metabolism Adaptive Thermogenesis (AT): in response to change in environmental temperature, increase blood flow to skin, shivering BMR (kcal/kg) varied by %FFM Highest in infancy, decline with age Can be estimated by equations
23
Ex Nutr c3-energy23 Components of total energy expenditure
24
Ex Nutr c3-energy24
25
Ex Nutr c3-energy25
26
Ex Nutr c3-energy26
27
Ex Nutr c3-energy27
28
Ex Nutr c3-energy28
29
Ex Nutr c3-energy29 Energy costs of different activities
30
Ex Nutr c3-energy30 Energy costs of different activities
31
Ex Nutr c3-energy31 Energy costs of different activities
32
Ex Nutr c3-energy32 Upper limits of energy expenditure Well-trained athletes can expend ~1000 kcal/h for prolonged periods of time Up to 9000 kcal/d in Tour de France More than 10000 kcal/d in extreme long- distance running Energy requirements can be met by most athletes, if well-planned (e.g. 20% CHO solution during exercise)
33
Ex Nutr c3-energy33 Energy balance in Tour de France
34
Ex Nutr c3-energy34
35
Ex Nutr c3-energy35
36
Ex Nutr c3-energy36 Components of energy expenditure Resting metabolic rate, basal metabolic rate Diet-induced thermogenesis, thermic effect of food Thermic effect of exercise
37
Ex Nutr c3-energy37 International physical activity questionnaire, IPAQ
38
Ex Nutr c3-energy38
39
Ex Nutr c3-energy39
40
Ex Nutr c3-energy40
41
Ex Nutr c3-energy41 Popular fat-buring tricks - 1 May not useful, depend on exercise type/intensity/duration and individual needs Carbohydrate tapering: eat high CHO in morning after ex, low CHO remaining the day Promote recovery of glycogen after exercise Burn more fat at night and during sleep Glycogen recovery may take several hours or longer after ex, may insufficient recovery Cardiomorning: perform endurance ex in morning Low glycogen before breakfast, more fat burning during ex Can only perform morning exercise at lower intensity May not reach maximal fat oxidation
42
Ex Nutr c3-energy42 Energy from fat in exercise with different intensities
43
Ex Nutr c3-energy43 Fat expenditure in exercise with different intensities
44
Ex Nutr c3-energy44 Popular fat-buring tricks - 2 Afterburn: not eating for several hours after endurance ex Increase fat oxidation after ex May induce protein breakdown after strenuous ex Light ex may not elicit sufficient fat oxidation Iron the cardio: weight training before endurance ex Decrease muscle glycogen during weight training, force higher fat oxidation during subsequent endurance ex Must involve the same muscle groups Higher intensity of endurance ex may negatively influence effect of resistance training on protein turnover Heavy endurance training should separate from weight training with the same muscle groups
45
Ex Nutr c3-energy45 A bout of endurance ex on protein turnover: post-ex supplementation
46
Ex Nutr c3-energy46 Designing optimal training diet for sport performance Determine energy expenditure Set goals for body weight and composition Set practical goals for distribution of diet energy into CHO, protein, fat In g/kg BW and en% Endurance athletes focus more on CHO, power athletes focus more on protein Distribute energy intake throughout meals and snacks during a day Timing is important Special attention to the first meal of the day Consider time of workout/training/work/class
47
Ex Nutr c3-energy47 Example: 75 kg male runner maintain weight, 4300 kcal/day
48
Ex Nutr c3-energy48 Example - continued
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.