Crew Health Advice：メンタルヘルスを向上させる運動

船上での生活は平凡とは程遠いものです。乗船中は長期間家を離れ、狭い居住空間や職場で過ごし、SNSへのアクセスも限られた日常生活となります。これらの環境は、孤独感やストレスにつながり、対処しなければうつ病や不安症など、より深刻な精神疾患に発展する可能性があります。本稿では運動がメンタルヘルスに与える影響と船上で運動を取り入れる方法について説明しています。

Understanding the Seafaring Lifestyle

The life of a seafarer is far from ordinary. Long durations away from home, confined living and working spaces, and the absence of usual social networks are commonplace. These factors can lead to feelings of isolation and stress, which, if not addressed, can escalate into more serious mental health issues such as depression or anxiety.

The Science of Exercise and Mental Health

Exercise as a Stress Reliever

Physical activity is a proven stress-buster. It stimulates the release of endorphins, often dubbed 'feel-good' hormones, which act as natural painkillers and mood enhancers. For seafarers, incorporating regular physical activity into their routines can be an effective strategy to manage stress, combat fatigue, and maintain mental alertness.

Mood Enhancement

Studies consistently show that exercise can elevate mood and decrease symptoms of depression and anxiety. The repetitive motions of exercise can create a form of meditation-in-motion, helping to break the cycle of negative thoughts that often dominate in depression. A simple regimen of daily exercise can be a proactive approach for seafarers to maintain a positive mood and stave off the blues.

Cognitive Benefits

Regular physical activity doesn't just strengthen the body; it also enhances the brain. Exercise increases heart rate, which pumps more oxygen to the brain and aids the release of hormones that provide an excellent environment for the growth of brain cells. For seafarers, whose jobs require constant alertness and quick decision-making, exercise can sharpen mental acuity and enhance cognitive flexibility.

Lack of physical activity has been extensively researched and linked to a variety of mental health disorders. Below are some of the mental health conditions associated with insufficient exercise, supported by research findings:

1. Depression

Numerous studies have established a strong link between physical inactivity and depression. The lack of exercise can contribute to the onset and severity of depressive symptoms. A meta-analysis published in the American Journal of Epidemiology found that even low levels of physical activity, including walking and gardening, could reduce the risk of depression. Another systematic review suggested that physical activity could be as effective as antidepressants or psychological therapies for some individuals, although it should ideally be used as a complementary therapy rather than a standalone treatment.

2. Anxiety

Anxiety disorders also correlate with low levels of physical activity. Research indicates that exercise can reduce symptoms of anxiety in a number of ways, including the reduction of stress hormones like adrenaline and cortisol, as well as the increase in endorphins, the body's natural mood lifters. A study from the Journal of Neuroscience has shown that regular exercise leads to changes in the parts of the brain that control stress and anxiety. Furthermore, physical activity provides a distraction, allowing people to find some relief from negative thoughts.

3. Dementia and Cognitive Decline

Lack of exercise is associated with an increased risk of cognitive decline and dementia, including Alzheimer's disease. Physical activity is believed to stimulate brain regions involved in memory function, such as the hippocampus, which is often one of the first regions to suffer damage in cognitive decline. Research published in the Neurology journal found that older adults who engage in regular physical activity are less likely to develop dementia compared to those who do not.

4. Stress

Chronic stress can be exacerbated by a lack of physical activity. Exercise is a proven stress reliever that decreases overall levels of tension, elevates and stabilizes mood, and improves sleep. Studies have shown that physically active people have lower rates of anxiety and depression than sedentary people. Exercise also increases concentrations of norepinephrine, a chemical that can moderate the brain's response to stress.

5. Sleep Disorders

Physical inactivity is linked to poorer sleep quality and changes in sleep patterns, which can lead to or exacerbate mental health issues. Regular exercise has been shown to improve sleep quality by helping to regulate the body's sleep-wake cycle, and by reducing feelings of anxiety and depressive symptoms which often interfere with sleep. A research study from the Journal of Clinical Sleep Medicine indicates that moderate to vigorous exercise provides significant improvements in the quality of sleep for individuals with sleep disorders.

6. Addiction

Exercise can also play a role in recovery from addiction by acting on neurotransmitter systems that are involved in mood and dependence, providing a natural and healthy way to stimulate dopamine pathways, which might otherwise be stimulated by drug use. Furthermore, a systematic review noted that exercise may help prevent substance use disorders from developing in the first place and serve as a beneficial element of addiction treatment programs.

7. Eating Disorders

Physical activity can be both beneficial and detrimental in the context of eating disorders, depending on how it is approached. While excessive exercise can sometimes be a part of eating disorder behavior, appropriate and moderated physical activity can play an important role in the recovery and management of conditions like anorexia and bulimia. Exercise in a controlled, healthy manner can help improve body image and reduce the symptoms of depression and anxiety that often accompany eating disorders.

Physical Health Benefits:

1. Cardiovascular health improves through regular physical activity, which is crucial given the limited medical help at sea.
2. Muscle strength and endurance are maintained, helping seafarers perform their duties effectively, which can be physically demanding.
3. Reduces the risk of chronic diseases such as obesity, heart disease, and diabetes, which are significant concerns given the sedentary aspects of long voyages.

Implementing Exercise Programs on Ships

Implementing a structured exercise program on ships can be challenging due to space constraints and the nature of the work. However, there are creative and effective ways to incorporate physical activity into a seafarer’s daily routine:

• Structured Exercise Programs: Ship management can integrate structured exercise programs that are designed to be performed in small spaces. Resistance bands, small hand weights, and yoga mats can be used effectively within limited spaces.
• Encouraging Active Breaks: Encouraging seafarers to take active breaks during their workday can help increase physical activity. Simple stretching exercises or quick walks around the ship can be integrated into their schedules.
• Use of Technology: Technology such as fitness trackers and apps can motivate seafarers by allowing them to monitor their progress and stay committed to their fitness goals.
• Mental Health Workshops: Combining exercise programs with mental health workshops can educate seafarers on the importance of mental health, further encouraging them to engage in regular physical activity.