How Does Physical Overwork Affect Immunity?


Overfatigue with high physical exertion leads to a sharp decrease in immunity. The situation is exacerbated by stress, lack of sleep and malnutrition.

Active sports and hard physical labour deplete the body’s resources. Energy is spent on working and muscle growth, increasing strength and repairing micro-fractures in muscle fibres. Other organs, including the immune system, suffer from a lack of energy and nutrients. For a while, immunity decreases, the ability to recognize pathogens of the disease and neutralize them deteriorates.

There is an open window theory. After long trainings that caused physical overwork, a “window” opens for infections to enter the body. During this period, the overall immunity and protective properties of the mucous membranes of the respiratory tract are reduced. The duration of the “window” is from 4 to 72 hours. Thus, even one hard training or one day of hard work is the cause of a short-term decrease in immunity.

Overtraining causes a prolonged decrease in immunity from 5 days to 3 weeks. Overtraining is a condition of the body caused by numerous heavy physical exertions. If you are a newbie you should not train over and should know about wrapping sprained ankles to avoid any injuries while working out. It is characterized by overwork, overstrain in individual organs (ligaments, muscles, bones), a decrease in hormone secretion, a decrease in the protective properties of the body, and a depletion of the nervous and immune system. The risk of viral and bacterial infections and exacerbation of existing diseases is increased 

Signs of overtraining:

  • Irritability
  • Fast fatiguability
  • Lack of appetite
  • Insomnia or drowsiness
  • Lack of coordination
  • Increased heart rate at rest for 12 or more beats
  • Menstrual irregularities in women
  • Decreased immunity

Categories of people at high risk of overwork:

  • Professional athletes, especially when preparing for competitions
  • People engaged in heavy physical labour – builders, machine operators, miners, agricultural workers, workers in enterprises where labour is not mechanized.

To avoid overtraining, follow these tips:

  • Rationally organize your work and training schedule;
  • Eat according to your gender, age, level of physical activity. Consume more protein, do not give up carbohydrates;
  • Enough rest – after heavy physical exertion 36-48 hours of rest are required. Light loads are allowed at this time.
  • Get enough sleep. Lack of sleep tends to accumulate. Sleep less than 7 hours a day for an active adult (8-9 for a child) leads to changes in the body.
  • Avoid stress.

How to determine the optimal level of physical activity?

The optimal level of physical activity depends on your age and state of health.

Types of physical activity. There is no ideal sport that would be useful to everyone, so your physical activity depends on your preferences and the presence of contraindications. For example, for health, swimming is one of the best sports, which hardens the body, gently strengthens muscles and joints, trains the heart and respiratory system. However, for some people, visiting the pool causes a runny nose, otitis media, or skin rash. Therefore, the choice must be approached individually, and people with chronic diseases should preferably consult a doctor.

All physical exercises can be divided into aerobic and anaerobic. It is believed that aerobic or cardio loads strengthen the heart and contribute to the burning of fat, while anaerobic or strength work on muscles and joints. Doctors say aerobic exercise is needed to extend life, and strength is needed to improve quality. For the harmonious development of the body, it is recommended to alternate both types of training.

A recommended heart rate means that 60-70% of your workout or walk time should go at the heart rate indicated for your age. If the whole activity is your heart rate of 90-100 beats per minute, then you are not training actively. The pulse above the indicated numbers over a long period of time says that the load is excessive and you are overtrained. The first and last 5-10 minutes of a lesson are a warm-up and a hitch. Exercises should be lighter, heart rate up to 100 beats per minute.

You can use the heart rate monitor or determine it yourself to determine your heart rate. During training there should be a feeling of slight difficulty breathing – you feel short of breath, but it does not interfere with speaking.

The number of workouts per week depends on your work schedule and physical abilities. To maintain good physical condition and normal immunity, you can choose one of the options.

People seeking to lose weight can increase their workout by 10-15 minutes without any risk to their health.

Before starting training, people older than 30 years who previously had not regularly been involved in sports are advised to have an ECG and consult their doctor.


To avoid reducing immunity during high physical exertion help:

  • A balanced diet rich in proteins, complex carbohydrates and vitamins;
  • Full sleep at least 7-8 hours a day;
  • Avoidance of psychological stress;
  • Rejection of bad habits;
  • Avoidance of overtraining.


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