Levels of growth hormone and testosterone are reduced by sleep loss, which could result in optimized motor learning and skills development among children. greater speed and accuracy on cognitive tasks among students. decreased muscle repair and energy among athletes.

The correct answer is **decreased muscle repair and energy among athletes.**<br /><br />Growth hormone and testosterone play vital roles in muscle growth, repair, and energy production. Sleep deprivation reduces these hormones, leading to:<br /><br />* **Impaired muscle repair:** Growth hormone is crucial for repairing muscle tissue damaged during exercise. Reduced levels mean slower recovery and increased risk of injury.<br />* **Reduced energy levels:** Testosterone contributes to energy levels and metabolism. Lower testosterone can lead to fatigue and reduced athletic performance.<br /><br /><br />The other options are incorrect:<br /><br />* **Optimized motor learning and skills development:** Sleep is essential for motor learning and skill development, but *lack* of sleep hinders these processes, not optimizes them.<br />* **Greater speed and accuracy on cognitive tasks:** Sleep deprivation negatively impacts cognitive function, leading to *decreased* speed and accuracy, not increased.<br />