The Idea of an Essay, Volume 2

145 this time from theta waves to delta waves (Epstein and Mardon 15). Delta waves are even larger, slower brain waves. Their rate usually ranges from 0.1 to 3.5 cycles per second (Pressman and Orr 17). Succession into this stage usually involves a reduction in breathing rate, blood pressure, and pulse, and the entrance to a level of sleep from which waking is more difficult (Epstein and Mardon 15). Finally, the nature of the last stage in this pattern, REM, distinguishes it as a unique process in itself. Epstein describes this stage as an “active brain in a paralyzed body” (17). During REM, many seemingly unusual occurrences take place: darting eyes; increased body temperature, blood pressure, heart rate, and breathing rate; a highly active sympathetic nervous system; and a temporary paralysis of the majority of the body’s muscles (Epstein and Mardon 17). One of the most notable characteristics of this stage lies in its facilitation of both memory and learning. Overall, REM occurs about every 90 minutes throughout a night of sleep, with its duration increasing as the night progresses. While the duration and frequency of each of the five stages differ, a single night of sleep usually involves several cycles. Each cycle, in turn, consists of multiple transitions between the different stages. Progression through these stages enables the body to carry out several psychological and physiological processes. The consideration of these effects places crucial emphasis on levels of adequate and inadequate sleep. On one hand, adequate amounts of sleep enable the body to restore and revive itself. Modern studies reveal such processing time as an essential aspect to formulating new, long-term memories: “Memory consolidation takes place during sleep through the strengthening of the neural connections that form our memories” (Harvard Medical). This reveals the association between sleep and memory improvement. However, sleep not only aids in memory formation, but it is also shown in several studies to affect physical performance. In the article “Sleep: The Athlete’s Steroid,” published in the IDEA Fitness Journal, Mike Bracko discusses several studies conducted concerning the effects of varying amounts of sleep on an athlete’s performance. One such study noted that when researchers increased the length of sleep for members of a swim team to “10 hours per day for 6-7 weeks . . . results showed that the swimmers swam the 15-meter sprint 0.51 seconds faster, reacted 0.15 seconds sooner off the start blocks . .