The Biology Behind Stamina

The Biology Behind Stamina

Stamina, according to the Oxford dictionary, is the physical or mental strength that enables you to do something difficult for long periods of time. In the context of sports, it refers to the ability to bear continual physical activity without succumbing to fatigue, injury, or trauma. 

Developing stamina involves exercising to a higher level of intensity so that your body gets used to it and thus gradually adapts to endure it. The more physically active one gets the more advantages they reap. 

The biology behind stamina can be explained through the following three categories:-

• Cardiac output- The heart is the organ that provides oxygen-rich blood to the muscle groups utilised during exercise. So, your endurance largely depends on the amount of blood your heart can pump each time it beats. The more the merrier. The part of the heart that pumps out blood through the aortic arch to the tissues in the rest of the body is called the left ventricle. Studies show that a condition referred to as the athlete’s heart is caused by long-term endurance training and is characterised by a larger left ventricle.

• Muscles – Oxygen is essential to generate the energy required to fuel muscle movement. The VO2max of a person which refers to the maximum (max) rate (V) 0f Oxygen (O2) that is distributed to and used by the muscles is the best measure of their aerobic endurance. Oxygen, which is absorbed into the bloodstream is further turned into energy molecules called Adenosine Triphosphate (ATP). Thus, the logic is simple- the higher the VO2 max of a person, the more oxygen they can absorb and utilise it to generate ATP energy molecules. This indicator of fitness isn’t fixed and can vary depending on the person’s training and their level of physical fitness. 

• Metabolic Mechanisms – Strenuous exercise often leads to metabolic acidosis or acid buildup. This happens due to the body’s inability to remove other metabolites and lactate quickly which ultimately leads to fatigue. Endurance is also fueled by some key metabolic factors like the body’s ability to remove lactate from the muscle tissue to avoid metabolic acidosis. The longer a body performs under high levels of stress, while simultaneously disposing of lactate, the longer it can endure that physical activity. 

Stamina also largely depends on one’s diet and this is where the proverbial saying, “You are what you eat” stands true. A person’s stamina and physical performance most certainly are affected by the food they consume. While the energy and specific diet required to be followed by a person largely differs from one sport to another there do exist some food groups that help build basic stamina. What these food groups have in common is that they all are large sources of complex carbohydrates, protein, iron, caffeine, and nutrients and minerals. 

• Complex carbohydrates- Carbohydrates are what mainly fuel our brain and muscles for physical activity and provide us with energy. Without carbs, one is often left feeling fatigued and dull during workouts. Bread, pasta, rice, etc are a few carbohydrate-rich food items that keep us energetic throughout the day.

• Vitamin C- This vitamin is what strengthens our immune system and protects us from viral fever, cough and cold. Illness often weakens us physically and lowers our stamina and endurance. The consumption of foods rich in vitamin C like oranges, lemons, broccoli, cauliflower, etc can prevent this eventuality of an infection weakening our endurance.  

• Iron- Iron is another important element of energy production as it is the iron in haemoglobin that transports oxygen to the rest of the body after its absorption by the lungs. The lesser the iron in one’s blood, the lesser the oxygen that reaches their cells and thus lesser ATP molecules are produced. Anaemia can be prevented by having iron-rich food like nuts, bananas, green leafy vegetables, beans, meat, etc.

• Proteins- Proteins are vital for the development, growth and repair of body tissues. It is an extremely vital component of increasing one’s stamina as it helps repair the muscles after engaging in intense physical activity. Protein-rich foods also prevent a person from overeating by increasing satiety.

Some protein-rich foods include Tofu, eggs, meat, lentils, etc.

• Oatmeal- Oatmeal is a food item that gets digested very slowly and thus makes the person feel full for a long time. It prevents the person from overeating, a habit that can disrupt one’s workouts and stamina. 

Stamina can further be divided into basic and advanced stamina.

Basic stamina forms the base for endurance performance which includes all forms of sports and the development of general fitness. In addition, basic stamina also acts as a stepping stone for the development of a high level of endurance. Solid basic stamina can usually be acquired through jogging, running, swimming or cycling.

Specific stamina is where things start to get a bit intense. It basically refers to the stamina levels required to perform in a particular sport- be it tennis, football, handball, basketball, or swimming. Since different sports possess different levels of intensity and utilise different muscle groups, the stamina level required for each is also very different. Depending on the sport in question, training to improve special stamina is in turn divided into short-term endurance, medium-term endurance and long-term endurance.

Now how exactly does one develop said stamina? Higher endurance is an ability that proves to be useful in many ways and developing it requires more than just consistency and a steady pace. High endurance development calls for higher intensity of physical activity and effort. Be it engaging in short high-intensity intervals of exercise or sustained high effort activities, a gradual increase in the difficulty of one’s workouts is what eventually will lead to an increase in stamina. Another important thing to remember while embarking on your fitness journey is to rest and recuperate whenever your body requires it. If one starts to feel that their energy and output levels are falling during a workout because of physical exhaustion, it may be a good idea to indulge in a rest day consisting of light activities like cycling, walking, yoga, etc. 

The most important aspect of increasing stamina is one’s mindset. It’s a well-known fact that the mind is more powerful than we give it credit for, especially when it comes to achieving difficult tasks. Hence, determination and the willingness to push ourselves forward are great qualities to possess while on your fitness journey.

While the psychological and physiological benefits of stamina are many, it also helps one focus on the physical activity they are engaging in without getting distracted by fatigue. It is an important prerequisite for a professional career in sports and proves to be helpful in many ways. Even if it is tough, developing stamina, without a doubt, is the key to achieving prime physical fitness.

-Shruti Reddy

FY BSc