“Look at these muscles, looking all big and strong” “Hey, can I stay next to the mirror? I would love to see my pumps”, “Ronaldo is insanely fit for his age; look at his packs.” When you hear athletes speak or others speak about how fit athletes are, they usually focus on their physical attributes like muscle mass and structure. After all, an athlete with 6 packs is fitter than a pot-bellied man.

Muscles are essential organs for every athlete and bodybuilder. Physical activity trains the muscles to be stronger and more defined. In turn, stronger muscles enhance athleticism. However, there’s more to an athlete than just muscles. Many other organ systems play essential roles in physical performance and are trained during exercise. Here, we look at some of these vital organ systems and their benefits to athletes.

Muscles and Physical Activity

Muscles benefit the most from physical activity. Workouts engage muscles, helping to build and strengthen them in the process. A more robust and more developed muscle structure benefits the body. Enhanced muscle mass protects bones and joints from injury, improves balance and coordination during movement, and enhances circulatory supply to other organs.

Regular exercise results in the following muscular changes;

  • Enlargement of muscle fibers and change in shape and size of muscles
  • Improvement of muscle tone
  • Increase in muscle strength in the long term
  • Increase in muscle protein stores
  • Increase in muscle blood and oxygen supply
  • Enhanced efficiency of ligaments and tendons that results in improved muscle movement and better stress tolerance.
  • Enhanced adaptability to stress and delay in muscle fatigue
  • Improved muscle structure that supports an improved skeletal structure, resulting in better physique and posture

The benefits of exercise on muscles and physical form are numerous. However, other organs also play essential roles in exercise performance and efficiency. Likewise, consistent workouts affect the physiology and performance of these systems.

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Other Systems involved in Exercise

Cardiovascular and Circulatory System

The cardiovascular and circulatory system consists of the heart and blood vessels. This system pumps and transports oxygenated blood to every organ, tissue, and cell in the body. This system also carries waste products away from these cells, helping to detoxify them.

Circulatory System and Exercise

During exercise, muscle fibers have increased oxygen and glucose requirements. The circulatory system, through blood, transports these required elements to the muscles to maintain exercise performance and efficiency.

Because muscles demand more oxygen and nutrients during workouts, the heart has to pump faster and harder than baseline to meet this increased demand. Thus, heart rate and blood pressure rise drastically during exercise. Measuring these parameters through monitors allows athletes to judge how intense their workout is. The heart rate and blood pressure must not go beyond a specific limit where it becomes dangerous to the athlete. Likewise, very low values during workouts may imply less efficiency and a need to pick up the pace.

Reduced circulatory functionality reduces exercise efficiency. Exercise routines must be tailored to their conditions in persons with heart problems like hypertension, hypotension, or arrhythmias. Overworking the heart in these conditions may cause more harm than good.

Effect of Exercise on the CIrculatory/Cardiovascular Systems

Prolonged exercise results in some permanent changes in cardiovascular morphology and functionality. The first observable (well, through a chest X-ray) change is an increase in the size of the heart. When you exercise, you also exercise the heart, which is itself a muscle. Prolonged exercise leads to an increase in heart size. Because the heart is enlarged and its walls thicker, smaller contractions produce greater pumping force, leading to larger blood output (stroke volume).

Thus, baseline heart rate and force of contractions reduce over time. For a non-athletic human, the heart beats an average of 72 times per minute (range: 60-100 bpm). However, for an athlete, the heart rate may be well below 60 beats per minute.

An athlete’s heart is more efficient and suffers less drastic changes in activity during workouts.

Digestive System

The digestive system consists of the mouth, esophagus, stomach, and small and large intestines that receive and process food and deliver nutrients to the systemic circulation. The digestive system is as important as any other system in the body. It plays a major role in determining exercise efficiency in athletes.

The Digestive System and Exercise

Food is necessary for life. However, the food we eat does not play any direct role in the body. When food is eaten, the digestive system breaks down macromolecules into easily absorbable forms. The digestive system also transports the products of the breakdown across the small intestine and into the bloodstream. The blood then carries the nutrients to all the organs and tissues where they are required.

Without the digestive system functioning optimally, there will be no glucose stores in the muscle for muscle fibers to burn during exercise. The digestive system ensures that all the cells in the body receive the nutrients necessary for optimal functioning.

Muscles are made up of proteins. Protein digestion is needed for larger and stronger muscles involved in workouts. During exercise, these muscles also require more glucose for energy production. It is the work of the digestive system to provide this glucose. In the absence of glucose, muscles and other cells in the body will break down fat for energy production. The digestive system is required for this process.

Digestive diseases like malabsorption syndrome can present with features of malnutrition. Without digestion, cells in the body will lack the nutrients required to function.

Effect of Exercise on the Digestive System

Consistent physical activity improves circulation to all body parts, including the digestive organs. Improved blood flow to the digestive walls enhances peristalsis and food movement down the gut. Enhanced peristalsis results in faster and healthier food digestion.

Besides its effect on digestive blood flow, exercise has also been shown to improve gut bacteria which is needed for food digestion and maintaining health overall. Studies show that patients with different digestive diseases like irritable bowel syndrome benefit immensely from aerobic exercises. Physical activity also relieves symptoms of constipation.

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Respiratory System

The respiratory system controls the intake of oxygen necessary for cellular metabolism. This system consists of the nose, pharynx, bronchi, alveolar, lungs, and blood.

Every cell in the body requires oxygen for its various processes. Breathing is an involuntary action that results in the intake of oxygen and carbon dioxide output. Air moves from the nostrils to the trachea during breathing, where tiny hair-like cells known as cilia trap dirt and mucus. From the trachea, decontaminated air then moves to the lungs.

In the lungs, oxygen is delivered to deoxygenated coming from the heart. The lungs then send the now oxygenated blood back to the heart to distribute to every cell that needs it, including cells of the lung.

Respiratory System and Exercise

Workouts are impossible without a functioning respiratory system. During physical activity, where muscle cells are engaged, their oxygen demand increases. To meet this increased oxygen demand, the respiratory system has to work more efficiently to collect and deliver oxygen to the blood, then supplied to the muscle cells for glucose breakdown.

Effect of Exercise on the Respiratory System

Consistent physical activity causes long-term changes to the structure and physiology of the respiratory system.

The lungs, chest, and other respiratory organs must work harder to meet the increased oxygen demand in exercise. The increased push exercises the lungs and chest, resulting in structural enlargement and efficiency. The diaphragm (the muscle that controls breathing action) and ribs also strengthen to accommodate the enlarged lung and chest.

Lung efficiency in prolonged exercise improves because inactive alveoli become activated, thus enhancing oxygen and carbon dioxide exchange between the lungs and blood. Workouts cause faster and deeper breaths, thus increasing residual air volume, tidal volume, and vital capacity. Increased vital capacity is needed to keep the body healthy.

Immune System

The immune system consists of the bone marrow, lymph, thymus, white blood cells, and complement system involved in protecting the body against various diseases.

The Immune System and Exercise

After a hard day of workouts, you feel sore all over – your muscles and joints hurt, and some parts feel inflamed. This is because the muscles get injured at a cellular level during physical activity.

In such a state, the immune system actively recruits immune cells to these injury sites to rapidly resolve the inflammation. A functioning immune system is thus needed for quick post-workout recovery. Besides, the immune system primarily protects against various pathogenic bacteria, fungi, and viruses. A functional Therefore, a functioning immune system ensures that an athlete maintains the good health necessary to engage in any routine in the first place.

Effect of Exercise on the Immune System

Immune cells circulate the body constantly. During exercise, lymph circulation increases, resulting in enhanced transport of these immune cells around the body. The enhanced circulation of immune cells means that they can navigate to locations where bacteria, viruses, and other disease-causing pathogens reside.

Exercise also influences the microbiome, notably the gut microbiome, an essential immune system component. Thus, physical activity helps to ensure that the body maintains optimal health.

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Physical activity primarily engages the muscles, resulting in larger and stronger muscles. However, many other organs and systems play essential roles in determining how efficient an athlete is in their routines. The heart and other components of the cardiovascular system, lungs and other components of the respiratory system, the organs of the digestive system, and all components of the immune system are super crucial for an athlete. Other systems such as the endocrine and nervous systems also play essential roles in an athlete’s life.

As an athlete, judging your progress through muscle growth is fine. However, you must remember that several other organs are essential in your journey. You must not neglect the organs that comprise these systems.


The Effects of Exercise on the Body Systems