ABSTRACT
Dietary protein and specific amino acids have been investigated for their effects on improving exercise performance. Due to the fact that dietary protein is not a primary source of energy, as carbohydrates and fats are, the effects that dietary protein intake imparts on exercise performance are usually chronic in nature. What this means is that dietary protein is not simply ingested prior to or following a single training bout
6.1 Introduction .................................................................................................. 155 6.2 Daily Protein Intake Recommendations ....................................................... 157
6.2.1 Factors Influencing Daily Protein Intakes ........................................ 159 6.2.1.1 Protein Quality ................................................................... 159 6.2.1.2 Energy Intake ..................................................................... 160
6.3 How Much Protein Should Be Ingested at Each Meal? ................................ 160 6.3.1 The Refractory Response of Skeletal Muscle to Elevated Plasma
Amino Acid Concentrations ............................................................. 162 6.3.2 The Role of Leucine ......................................................................... 163
6.4 Protein Timing-How Often Should Protein Be Ingested during the Course of the Day? ....................................................................................... 164
6.5 Safety Issues with Elevated Protein Intakes ................................................. 165 6.6 Protein and Exercise Performance ............................................................... 167
6.6.1 Endurance Exercise .......................................................................... 168 6.6.1.1 Central Fatigue Hypothesis ................................................ 170
6.6.2 Resistance Exercise .......................................................................... 171 6.6.2.1 Protein and Net Muscle Protein Balance ........................... 171 6.6.2.2 Comparison of High-Quality Proteins ............................... 172
6.7 Conclusion .................................................................................................... 176 Acknowledgment ................................................................................................... 177 References .............................................................................................................. 177
and improvements in exercise performance/body composition are realized by the next day. In contrast, the effect that dietary protein has on enhancing performance or body composition is a process. In short, the process can be summarized as the following:
• The training session imparts a stimulus to the body. • The body adapts to the stimulus over time, resulting in adaptations that are
favorable for improving performance/body composition.
