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Can exercise affect immune function to increase susceptibility to infection?
Richard J. Simpson, Richard J. Simpson, Maree Gleeson, Maree Gleeson, Karsten Kruger, David B. Pyne, David B. Pyne, Neil P. Walsh. Exercise immunology review, 2020-01-01
Topic: Brain proteins, microglia and lab models
Multiple studies in humans and animals have demonstrated the profound impact that exercise can have on the immune system. There is a general consensus that regular bouts of short-lasting (i.e. up to 45 minutes) moderate intensity exercise is beneficial for host immune defense, particularly in older adults and people with chronic diseases. In contrast, infection burden is reported to be high among high performance athletes and second only to injury for the number of training days lost during preparation for major sporting events. This has shaped the common view that arduous exercise (i.e. those activities practiced by high performance athletes/ military personnel that greatly exceed recommended physical activity guidelines) can suppress immunity and increase infection risk. However, the idea that exercise per se can suppress immunity and increase infection risk independently of the many other factors (e.g. anxiety, sleep disruption, travel, exposure, nutritional deficits, environmental extremes, etc.) experienced by these populations has recently been challenged. The purpose of this debate article was to solicit opposing arguments centered around this fundamental question in the exercise immunology field: can exercise affect immune function to increase susceptibility to infection. Issues that were contested between the debating groups include: (i) whether or not athletes are more susceptible to infection (mainly of the upper respiratory tract) than the general population; (ii) whether exercise per se is capable of altering immunity to increase infection risk independently of the multiple factors that activate shared immune pathways and are unique to the study populations involved; (iii) the usefulness of certain biomarkers and the interpretation of in vitro and in vivo data to monitor immune health in those who perform arduous exercise; and (iv) the quality of scientific evidence that has been used to substantiate claims for and against the potential negative effects of arduous exercise on immunity and infection risk. A key point of agreement between the groups is that infection susceptibility has a multifactorial underpinning. An issue that remains to be resolved is whether exercise per se is a causative factor of increased infection risk in athletes. This article should provide impetus for more empirical research to unravel the complex questions that surround this contentious issue in the field of exercise immunology.
Key findings
- Multiple studies in humans and animals have demonstrated the profound impact that exercise can have on the immune system.
Why it matters
This debate article asks whether exercise itself can weaken immune function and raise infection risk, and it notes that this idea has recently been challenged because athletes also face anxiety, sleep disruption, travel, exposure and nutritional deficits. It does not address treating, curing or preventing Alzheimer's disease.
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Study details
- Evidence strengthLow
How this study scored 47/100
Published in a peer-reviewed journal. Scored zero for study design, sample size, effect reported, studied in people and randomised / blinded because the record does not state it. We have no data on journal's citation record, so that was left out: it earned 45 of the 96 points we could judge it on, which is 47 out of 100.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (Exercise immunology review) |
| Journal's citation record | — / 4 | No journal record from OpenAlex — left out of this score |
| Study design | 0 / 12 | No study design recorded — scores zero, not guessed (not stated in the record — scored 0) |
| Strength of evidence | 1 / 5 | Rated “low” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 2 / 5 | 2020 — within 10 year(s) of the newest study here |
| Sample size | 0 / 4 | Participant count not stated — scores zero (not stated in the record — scored 0) |
| Effect reported | 0 / 3 | No effect size reported — scores zero (not stated in the record — scored 0) |
| Studied in people | 0 / 3 | Not stated whether this was studied in people — scores zero (not stated in the record — scored 0) |
| Randomised / blinded | 0 / 2 | No randomisation or blinding stated — scores zero (not stated in the record — scored 0) |
| Times cited | 6 / 7 | Cited 367 times (OpenAlex, 2026-10-10) |
| Citations per year | 4 / 5 | 45.9 citations a year over 8 year(s) since 2020 |
| Impact for its field and year | 3 / 6 | Cited 5.2× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 0 / 6 | No other study in this library cites it |
| Still being cited | 3 / 4 | Cited 67 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 2 / 4 | Last-listed author Neil P. Walsh: h-index 48 (OpenAlex, whole career) |
| Institution's track record | 1 / 3 | University of Arizona: institution h-index 1,336 (OpenAlex) |
| Multi-centre collaboration | 2 / 3 | OpenAlex lists 7 institution(s) in 4 countries |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 32139352) |
| Free to read | 2 / 2 | Free to read |
| Points | 45 / 96 | Scored on 19 of 20 parts. We have no data for the rest, so they are left out: 45 of the 96 points we could judge it on is 47 out of 100. |
| Total | 47 / 100 | — |
What each of these 20 components measures, and what this score is not →
Read the original
- DOI: 10.22029/eir.2020.1730
- PubMed: 32139352
- Original source →
- Free full text: Griffith Research Online →
Full text: free to read — OpenAlex lists this copy as free to read: the link above (checked 6 Feb 1020).
Cite this study APA, Vancouver, BibTeX · download .bib or .ris
Built from the record alzhub holds for this paper, not looked up. Volume, issue and page numbers are not held in the record. Check the citation against the original before you use it.
APA 7th
Simpson, R. J., Gleeson, M., Kruger, K., Pyne, D. B., & Walsh, N. P. (2020). Can exercise affect immune function to increase susceptibility to infection? Exercise immunology review. https://doi.org/10.22029/eir.2020.1730
Vancouver
Simpson RJ, Gleeson M, Kruger K, Pyne DB, Walsh NP. Can exercise affect immune function to increase susceptibility to infection? Exercise immunology review. 2020. doi:10.22029/eir.2020.1730. PMID: 32139352.
BibTeX
@article{simpson2020-32139352,
author = {Simpson, Richard J. and Gleeson, Maree and Kruger, Karsten and Pyne, David B. and Walsh, Neil P.},
title = {{Can exercise affect immune function to increase susceptibility to infection?}},
journal = {Exercise immunology review},
year = {2020},
doi = {10.22029/eir.2020.1730},
pmid = {32139352},
url = {https://doi.org/10.22029/eir.2020.1730}
}