chapter  5
32 Pages

Laboratory Methods for Determining Energy Expenditure of Athletes

ByRobert G. McMurray

Determining energy expenditure for athletes can have a positive impact on their health and their ability to train and compete. Knowing the energy demands of practice can help the athlete maintain a positive energy balance (energy demands vs. energy intake), which optimizes the ability of the athlete to train and to increase muscle mass. For example, inadequate energy intake reduces the ability of the athlete to sustain training at high intensities or to exercise for extended periods, and has the potential to increase his or her risk of injury. Inadequate intake of energy also

5.1 Introduction .................................................................................................. 151 5.2 Methods for the Measurement of Metabolic Rate ........................................ 153

5.2.1 Direct Calorimetry ........................................................................... 153 5.2.2 Indirect Calorimetry ......................................................................... 154 5.2.3 Doubly-Labeled Water ...................................................................... 158 5.2.4 Indirect Methods of Estimating Energy Expenditure ...................... 159

5.3 Energy for Work and Sport ........................................................................... 161 5.4 Metabolic Measurements Specific to Athletes ............................................. 163

5.4.1 Aerobic Power or VO2max .................................................................. 163 5.4.2 Anaerobic Threshold ........................................................................ 166 5.4.3 Economy of Movement ..................................................................... 168

5.5 Resting Energy Expenditure ......................................................................... 169 5.5.1 Measurement of Resting Energy Expenditure .................................. 170 5.5.2 Estimating Resting Energy Expenditure .......................................... 170 5.5.3 Factors Influencing Resting Energy Expenditure ............................. 171

5.6 Estimating Daily Energy Expenditure.......................................................... 175 5.7 Future Research Concerns ............................................................................ 175 5.8 Conclusions ................................................................................................... 176 References .............................................................................................................. 177

reduces the anabolic muscle-building process. From another perspective, measuring maximal energy capacity can provide the athlete with information regarding the effects of the training program on metabolic adaptations. Also, knowing at what exercise intensity the athlete starts to produce significant lactic acid can assist the athlete in identifying the proper intensity at which to train to obtain maximal metabolic benefits. This chapter focuses on the present state of knowledge regarding the methods of measurement of energy use and provides some insights into how these measurements can benefit the athlete.