Roberto N. Barbosa and James M. Gregory
Sleep is essential for human life and gives the body the opportunity to repair itself. Bodily functions change during sleep: hormones are secreted, blood pressure is lowered, kidney function changes, and memory is consolidated. Good sleep is more than just a good feeling; it is an issue of health, wellness and safety.
Farming is a profession that involves long hours of work. Producing crops and securing a family’s financial survival translate into long hours in the field. And long hours of tough, physically demanding labor may come at a high price. Lack of proper sleep and the associated loss of alertness are common ingredients in work-related accidents. Computer simulations with a sleep model indicate that a middle-aged farmer reducing his sleep by one hour per day during planting season will increase his risk of accidents by 20 times. The National Sleep Foundation estimates that sleep deprivation and sleep disorders cost Americans $100 billion dollars in lost productivity, medical expenses and property damages. Also, approximately 70 million Americans are affected by sleep problems.
Sleep is a brain-operated process. Restorative or homeostatic control regulates the drive to sleep in response to how long we have been awake. The longer we are awake, the stronger the drive to sleep. Caffeine disrupts this process and temporarily alters the need for sleep. A second process controls the timing part of the brain that controls this timing is influenced by bedtime and light, making us naturally sleepy at night and active during the day. Adequate quantity and quality sleep refreshes the body and brain for the next day.
The exact amount of sleep a person needs depends on several factors. In general, the older we are, the less sleep we need. Infants and children need the most sleep. Infants less than 12 months of age may sleep more than 14 hours a day. A 12-year-old child needs nine to 11 hours of quality sleep. Physical exercise, such as labor-intensive fieldwork, increases the need for sleep. A physically active 60-year-old farmer may need between seven and eight hours of sleep every night after days of hard work, compared to only six to seven hours of sleep on days of less physical activity. Children often want to follow an adult schedule for sleep, but research indicates that adolescents sleeping less than 9 hours per day have elevated risks of injuries.
Sleep is cyclical and involves two states defined by brainwave patterns that alternate every 90 to 110 minutes. This process is repeated four to six times per night. The first state – called NREM (nonrapid eye movement) – is composed of four stages. Stage 1 starts as light sleep, which becomes increasingly deeper and of better quality as the stages progress. Stages 3 and 4 of NREM sleep are also known as delta sleep.
The second state of sleep is known as REM or rapid eye movement. The brainwaves in this state are similar to that of being awake. The brain is actively dreaming, and the eyes are rapidly moving back and forth.
The time spent in each sleep state and stage varies throughout life. As aging occurs, both REM and delta sleep decrease. Many inactive, older people have little or no delta sleep.
Researchers have found that sleep loss may have harmful consequences to the immune and endocrine systems – systems that are responsible for protection against diseases and the regulation of hormone secretion – and contribute to serious illnesses such as obesity, diabetes, hypertension and heart disease. Sleep apnea is a disorder in which breathing stops periodically during sleep. People with mild to moderate sleep apnea performed as badly or even worse in reaction-time tests as people with above-the-limit alcohol levels in their systems.
Mood disorders are probably the most recognizable symptom of lack of sleep. A growing number of medical tests link lack of sleep with anger, anxiety and sadness. Cardiovascular diseases – including increased blood pressure and the risk of a stroke – are associated with both long- and short-term sleep losses.
Improve sleep management by doing the following:
- Avoid caffeine, alcohol and nicotine close to bedtime.
- Exercise regularly but at least three hours before bed time. Exercise helps us to fall asleep and contributes to a deeper sleep.
- Create a sleep-conducive environment that is dark, quiet and preferably cool and comfortable.
- Maintain a regular bed and wake time, even on weekends.
- Don’t eat before going to bed. Overeating and the consumption of spicy food before sleep can cause discomfort and contribute to poor sleep quality.
- Treat pain to minimize interference with sleep.
- Make up for lost sleep whenever you can, such as sleeping an extra hour on a rainy day.
Roberto N. Barbosa, Assistant Professor, and James M. Gregory, Adjunct Professor, Department of Biological & Agricultural Engineering, LSU AgCenter, Baton Rouge, La.
(This article was published in the fall 2008 issue of Louisiana Agriculture.)