What Are the Causes of Arm Muscle Fatigue?

Tired arms and hands, tired legs and tired shoulders: These may be the consequence of a number of physical conditions and lifestyle choices. Pregnancy and overuse are among several factors that could be causing your muscles to feel weak.

The risks of arm fatigue can be classified with risks for all muscle fatigue. According to a May 2013 article published by ‌Frontiers in Physiology,‌ in a healthy individual, muscle fatigue can be temporary and recovery may occur quickly. However, when muscle fatigue stems from certain factors, such as chronic disease, lifestyle choices or injury, it may persist.

When muscle weakness is persistent, this may lead to risks and perpetuate a cycle of inactivity and muscle wasting that exacerbates certain diseases and conditions, such as hypertension and metabolic syndrome. There are several factors that can cause muscle fatigue, including pregnancy, age, overuse, lack of use and disease.

‌Read more:‌ How to Recover From Muscle Fatigue After Exercise

It's not uncommon to experience tired arms and legs during pregnancy. In a 2016 article by Patient.info, general practitioner and medical author Dr. Mary Harding suggests that high levels of steroids in the blood combined with a lack of iron can cause muscle weakness. Despite muscle tiredness, you may still do some light exercises. Just be particularly careful while exercising and consult your doctor about which physical activities you can do.

Age is another factor when it comes to muscle fatigue. As we age, our muscles tend to weaken. That said, exercise is still essential as we get older, as it helps increase muscle power and strength. Just be sure to exercise carefully and it can even be advisable to have supervision in certain cases.

According to Dr. Harding, "lack of use" may also be a cause of muscle fatigue. Lack of muscle use, or deconditioning, can happen as a result of a sedentary lifestyle. When muscles go unused, the muscle fibers are partly replaced with fat.

Consequently, muscles lose bulk and tire more easily during physical activity. For example, if your muscles are inactive, you may experience arm fatigue or forearm fatigue when lifting a heavy box or bag that may not have felt as heavy when your muscles were fit.

On the other side of lack of use, there's overuse. Overusing your muscles during physical activity or over-training, is yet another reason why you may be fatigued after a workout. The Mayo Clinic points out that overuse can be caused by errors in training, such as taking on too much physical activity too quickly, or technique errors, which would involve using poor form.

You can avoid overuse by pacing yourself, using the proper form and gear, and slowly increasing your level of activity.

‌Read more:‌ The Dangers of Working Out Too Much

Dr. Harding describes several chronic diseases associated with muscle weakness, which in some conditions can be attributed to reduced blood and nutrient supply to your muscles.

Examples of these diseases include anemia, which reduces the ability of blood to carry oxygen to the muscles; diabetes, which lowers the blood supply to the small nerves; peripheral arterial disease, which is related to the build-up of cholesterol; and heart disease, which reduces blood supply at times of high demand.

Other diseases that may cause tired muscles are chronic kidney disease and chronic lung disease. Muscles can also be affected by certain sleep disorders or syndromes, such as chronic fatigue syndrome, fibromyalgia, underactive thyroid and muscle inflammation.