Sleep patterns and exercise
Sleep can be broken down into 5 stages. It takes us between 5 & 10 mins for the mind and body to relax and be ready for Stage one. Stage one lasts between 10 secs & 10 mins. Our breathing is shallow and our muscles will rapidly relax. (sometimes we feel a sense of falling which results in a physical reflex)
Stage 2 lasts between 10 & 20 mins. This marks the beginning of actual sleep and we are blind and deaf to external stimuli. Stages 3 & 4 are the deepest part of sleep – closest to hibernation. It is during this stage that our recovery processes peak. Metabolic activity decreases and the hormonal system increases the release of growth hormone. After 30 – 40 mins of stage 4 we return to stage 3 then 2. From here we move into rapid eye movement (REM) sleep.
During REM sleep, blood flow, pulse, breathing, temperature and blood pressure all increase and our eyes move rapidly. Dreams may occur during REM.
Throughout our sleep we may repeat the above cycle 4 to 6 times.
On average adults require 7 to 8 hours of sleep per night. If we are deprived of sleep research shows our cardiovascular performance drops. Some studies indicate this can be more than 10%, a significant handicap for those sports men/women looking to maximise their performance. Also, our mental functioning decreases even more significantly. So, even if you still feel physically fit you may find it harder to recall tactical information or make rapid decisions e.g. on the football field. Even minimal sleep loss will affect emotional well being, leaving us feeling down and depressed.
The amount of sleep we need varies from person to person. Next week we will look at how to determine exactly how much sleep we each need – and for those not getting enough sleep what practical steps can be taken to help.