Overview

There are diverse factors that can be related to the involuntary, continuous movements of the legs known as restless legs syndrome.¹ In this article, we will analyse the most common factors associated with the syndrome, the diagnostic criteria, and the general treatment. We will also analyse the role of different types of exercises that have been used as a complementary treatment in many cases.² 

What is restless legs syndrome?

Willis-Ekbom disease, more commonly known as restless legs syndrome, is a condition in which the person feels an uncomfortable and imminent necessity to move their legs. It usually starts while resting and can be worse during sleeping, affecting the quality of sleep.³ 

This syndrome can begin in different stages of life, but symptoms are more common in adults aged 40 years and decrease after 64 years of age. Additionally, it tends to affect people assigned as female at birth more, probably because of the influence of hormonal changes and/or pregnancy.⁴

Causes of restless legs syndrome

This is catalogued as a disorder, in which there are abnormal muscle movements caused by a dysfunction in the nervous system. Dopamine, which is a neurotransmitter related to the movements of the muscles, has been linked as one of its main causes. However, the specific cause behind restless legs syndrome is unknown.⁵

While this syndrome is not associated with a particular disease, it has been associated with the presence of diverse factors. Next, we will review some of the usual factors that are linked with this condition. 

Genetics

In between 25% to 75% of the cases, there is an antecedent of other persons in the family with the syndrome. Usually, in these cases, persons start with symptoms earlier in their lives, but these symptoms have a slower progression.

Pregnancy

In the third trimester of pregnancy, restless legs syndrome is very common, however, one month after delivery, the symptoms go away. Although there is no known specific cause, the deficiency of iron and the levels of hormones during pregnancy have been linked as factors that influence the presence of this syndrome.⁶

Iron deficiency

Low levels of iron in the body have been associated with this syndrome. It is because when there is iron deficiency in the brain, the transmission of dopamine has been found to be diminished and the symptoms of the syndrome have been worse.

Chronic conditions

Different conditions like diabetes, rheumatic arthritis, fibromyalgia and celiac disease have been linked with restless legs syndrome, but with a very vague association. In the case of end-stage renal disease and patients on hemodialysis, it has been estimated that between 20% to 30% of the persons have this syndrome and the symptoms diminish after a kidney transplant.⁷

Drugs

Alcohol, tobacco and caffeine have been linked with the presence of restless legs syndrome, this is because they can stimulate the movements of the muscles. In addition, medications such as tricyclic antidepressants (TCAs), serotonin-norepinephrine reuptake inhibitors (SNRIs), selective serotonin reuptake inhibitors (SSRIs), beta blockers, or diphenhydramine are related to causing or worsening this syndrome. 

Diagnosis of restless legs syndrome 

The International Restless Legs Syndrome Study Group (IRLSSG) made a revision of the different criteria for the diagnosis of the disease. The essential criteria are:

• The urgent necessity of moving the legs, it may or may not be linked with unpleasant sensations in the legs
• This imminent necessity of moving the legs starts, or it is worse while resting, sitting or lying down
• Depending on how strong the symptoms are, the person feels better, during and after, moving or stretching
• These movements and sensations can start during the day, but usually can get worse, during the evening or night
• The movements are not associated with another medical or behavioural condition

In addition, the symptoms are classified considering the continuity of their presence: 

• Persistent or chronic, when the symptoms occur twice a week in a year, without any treatment
• Intermittent, when the symptoms happen less than two times a week in a year, without treatment, and at least five times during lifetime^3,5

Although the next clinical features are not part of the diagnosis, they are taken into account to support the diagnosis: 

• The presence of Periodic Limb Movements of Sleep (PLMS), mainly when the movements are very intense
• The reduction of the symptoms after dopaminergic treatment, even if it is for a short period of time
• Other cases in first-degree relatives in the family
• Poor sleeping patterns

Finally, it is analysed if the presence of the syndrome is interfering or causing problems in daily activities of the individuals. For example, if it can be related to poor performance at school or work because of bad sleep quality, or altered behaviour.⁸ 

Treatment of restless legs syndrome

The treatment depends on the severity of the symptoms, as well as how much they interfere with the individual's daily life. Medications are not required in all of the cases, mainly when the symptoms are mild.

In general, some changes in the lifestyle that can be helpful: 

• To avoid drugs or substances that can generate or worsen the symptoms, such as alcohol, caffeine, tobacco
• To follow measures that can be useful to improve the quality of sleep, the set of these measures is known as sleep hygiene 
• If there is suspicion about some medication that could be causing the symptoms, it is crucial to go to your doctor and review your medications
• To exercise regularly⁹ 

How can exercise help restless legs syndrome?

Exercise is part of the general measures that can be helpful to improve the symptoms. Nevertheless, exercise cannot be used as the main treatment for this syndrome, it is an auxiliary treatment. For example, dopaminergic treatment in low doses, and aerobic exercise, which consists of cycling 3 days a week, were used in patients on hemodialysis for 6 months. These measures, together, were very helpful to reduce the symptoms of restless legs syndrome in the patients.¹⁰

Types of exercises that may help

There are diverse investigations that have tested the use of different types of exercise to reduce the symptoms of restless legs syndrome. We will analyse some of them below.

Stretching

These exercises were used in patients with hemodialysis that suffered moderate symptoms. The stretching exercises were done for 30 minutes, 3 times a week during 8 weeks. The patients felt an improvement in their symptoms.¹¹ 

Resistance, stretching and aerobic exercises

The combination of resistance, stretching and aerobic exercises were used in patients diagnosed with the syndrome. The program was followed for 4 weeks, in which the patients had to do resistance exercises, stretching exercises and the aerobic exercise was to walk for 30 minutes. Additionally, the participants were helped in making changes in their lifestyle, for example, to avoid coffee or alcohol. In the end, their symptoms improved. 

Yoga

Yoga was used in patients with moderate and severe symptoms. For 12 weeks, participants completed a yoga program. The first 4 weeks, patients did 2 sessions of 75 minutes. Then, next 8 weeks, with 1 session of 75 minutes per week, and a routine of 30 minutes to do as homework per 5 days a week. In the end of the intervention, patients improved their symptoms and their quality of sleep. Although this study suggests that yoga could be a substitute of the medications, it requires more studies, however, yoga could be used as an auxiliary treatment.¹²

When to seek help?

The restless legs syndrome is not a medical emergency by itself, but it is important to look for medical help if you think that you, or someone near to you, could have this syndrome. Even in cases with mild or moderate symptoms, these can worsen and start affecting your sleep quality and/or your daily activities. 

Summary 

The specific cause of this syndrome is not completely known, but many factors are associated with it. The diagnosis requires looking for specific criteria in the symptoms of the patients. Independently of the factors presented, the general treatment requires a change in the lifestyle.

There are different types of exercises that can be helpful to improve the symptoms, however, exercise cannot be used as a substitute for medical treatment when it is required. Therefore, it is crucial to go to the doctor to have a correct diagnosis and to start with a guided treatment that allows people to have a good quality of sleep that does not interfere with their daily routines.