Future directions in exercise and immunology: regulation and integration.
Mackinnon, L T · International journal of sports medicine · 1998 · DOI
Quick Summary
This editorial discusses how exercise affects the immune system and raises important questions for future research. It explores whether athletes' bodies are actually fighting infections less effectively, whether reducing certain immune responses might sometimes be helpful, and how exercise training might help people with conditions like chronic fatigue syndrome improve their immune function.
Why It Matters
For ME/CFS patients and researchers, this editorial is significant because it explicitly identifies chronic fatigue syndrome as a condition where exercise training may have immunotherapeutic potential, and it highlights the need to understand how exercise influences immune communication and tolerance. It suggests that moderate, carefully-calibrated exercise might help restore immune function in ME/CFS, though it also raises cautionary questions about inflammation and immunosuppression.
Observed Findings
Endurance athletes show increased illness risk despite absence of clinical immunodeficiency
Neutrophil downregulation occurs in athletes and may reflect adaptation to limit chronic inflammation
Exercise increases cytokine levels in damaged skeletal muscle and increases adhesion molecule expression
Mild immunosuppression in athletes may represent a balance between limiting inflammation and maintaining immune function
Inferred Conclusions
Moderate exercise training may stimulate immune function in certain disease states including chronic fatigue syndrome
The relationship between infection, training variables, and immune parameters requires systematic long-term investigation
Cytokines and adhesion molecules likely mediate communication between skeletal muscle and the immune system during and after exercise
Molecular biology techniques are needed to elucidate the mechanisms by which exercise influences immune function
Remaining Questions
Are athletes truly immunocompromised, or do they experience a transient, beneficial shift in immune regulation?
Is neutrophil downregulation in athletes protective against chronic inflammation or harmful to infection resistance?
What This Study Does Not Prove
This editorial does not provide empirical data and therefore does not prove that exercise training is beneficial or safe for ME/CFS patients. It raises hypothetical questions rather than answering them, and it does not account for post-exertional malaise or the distinct pathophysiology of ME/CFS, which may differ fundamentally from exercise-induced immune changes in healthy athletes.
About the PEM badge: “PEM required” means post-exertional malaise was an explicit required diagnostic criterion for participant inclusion in this study — not that PEM was studied, observed, or discussed. Studies using criteria that do not require PEM (e.g. Fukuda, Oxford) are tagged “PEM not required”. How the atlas works →