Hormone production is dependent on your sleep. For testosterone production, you need at least 3 hours of uninterrupted sleep, which is about the time of your first R.E.M. episode. Waking up throughout the night could affect hormone production.

This interruption can also affect growth hormone production , especially in children and adolescents. These hormones help the body build muscle mass and repair cells and tissues, in addition to other growth functions.

The pituitary gland releases growth hormone throughout each day, but adequate sleep and exercise also help the release of this hormone.