Exercise and the Immune System

What are the two main components of the immune system?

• The innate immune system

  • Physical, cellular system, complement system

• acquired immune system.

  • Adaptive or specific immune system

What physical barriers are part of the innate immune system?

Skin and mucus membranes.

• Complement proteins

Which cells are key components of the innate immune system?

Neutrophils and macrophages

• release cytokines

What are cytokines?

Cytokines are signaling proteins that mediate and regulate immunity, inflammation, and hematopoiesis.

What are B cells (B lymphocytes) responsible for in the acquired immune system?

They secrete antibodies to fight against foreign antigens.

• Best Cells → B Cells

What are the different types of antibodies produced by B cells?

IgG, IgA, IgM, IgD, IgE.

• Antibodies called immunoglobulins

• Fight against foreign antigens

What are the three types of T cells?

T cells are a subtype of white blood cells that are pivotal in the immune system. They originate in the bone marrow but mature in the thymus. There are several types of T cells, including:

• Helper T cells (CD4+ T cells): They assist other immune cells by releasing cytokines, which help orchestrate the immune response.

• Killer T cells (Cytotoxic T cells): They directly kill infected cells, cancer cells, and sometimes cells that are damaged in other ways.

• Regulatory T cells (Tregs): They help maintain immune tolerance, preventing immune system from attacking normal body antigens

What is the impact of moderate aerobic exercise on the risk of upper respiratory tract infections (URTI)?

Moderate aerobic exercise protects against infections and may reduce the risk of URTI

• Reduces risk of URTI 18-67%

• 20-40mins

• @ 40-60% VO2 max

• Resistance training may also help

What is the mechanism behind regular exercise reducing the risk of upper respiratory tract infections (URTI)?

Regular exercise decreases the risk of upper respiratory tract infections (URTIs) by:

• enhancing circulation of immune cells throughout the body

• reducing chronic inflammation

• regulating stress hormones like cortisol

• improving sleep quality

• promoting lymphatic flow to transport immune cells.

Exercise and resistance to infection?

• Regular, moderate exercise decreases risk of URTI

• Increased risk of URTI w/ intense and/or long duration exercise

• Exhaustive exercise triggers illnesses

  • Causes IMMUNOSUPPRESSION and provide an opportunity for infections

What is immunosuppression?

Immunosuppression is the reduction of the immune system's ability to fight infections and diseases, often induced by medications.

What are factors that affect susceptibility to infection in atheletes?

• Increased exposure to pathogens

• Exercise-induced immune suppression

• Inadequate diet

• mental stress

• lack of sleep

What happens to the risk of URTI with high intensity or long duration aerobic exercise?

It increases the risk of URTI due to the 'open window' effect.

• Decreases levels of:

  • B cells

  • T cells

  • natural killer cells

• Decreases natural killer cell and t cell function

• Decreased neutrophil phagocytosis

• decreased nasal and salivary IgA

• INCREASED cytokines

  • If Bad cytokines are released

    • exacerbates the infection itself

  • Induces immunsuppression

When is it safe to exercise if you have a cold?

It’s safe to exercise if symptoms are above the neck, such as a mild sore throat or runny nose.

What should you avoid if you have symptoms below the neck while having a cold?

You should not exercise if you have

• chest congestion

• cough

• stomach pain.

What effect does regular exercise have on natural killer cells and lymphocytes?

Exercise boosts the levels of natural killer cells and lymphocytes.

What factors contribute to increased susceptibility to infection in athletes?

• Increased exposure to pathogens

• exercise-induced immune suppression

• inadequate diet

• mental stress

• lack of sleep

What role do T cells play in the acquired immune system?

T cells, including killer T cells and helper T cells, combat virus-infected cells and enhance the immune response.

What was one finding about the effects of sedentary behavior on vaccine effectiveness?

Sedentary behavior decreases vaccination-induced immunogenicity.

According to WHO recommendations, how much exercise should healthy adults do per week?

At least 150 minutes of moderate exercise per week.

What is the importance of exercise for individuals with pre-existing comorbidities during the COVID-19 pandemic?

Exercise may improve outcomes like reduced mortality from pneumonia and enhanced immune response.