Top
Introduction
Physical Inactivity
Results
Exclusions
Conclusion
Study Notes
Methods and Data
Supplementary
References

All studies
Mortality
Ventilation
ICU admission
Hospitalization
Progression
Recovery
COVID-19 cases
Peer reviewed
Exclusions

Feedback
Home
Show Outline
Top   Intro   Inactivity   Results   Exc.   Conclusion   StudyNotes   Appendix   SupplementarySupp.   ReferencesRef.
Home   COVID-19 treatment studies for Exercise  COVID-19 treatment studies for Exercise  C19 studies: Exercise  Exercise   Select treatmentSelect treatmentTreatmentsTreatments
Alkalinization Meta Lactoferrin Meta
Melatonin Meta
Bromhexine Meta Metformin Meta
Budesonide Meta Molnupiravir Meta
Cannabidiol Meta
Colchicine Meta Nigella Sativa Meta
Conv. Plasma Meta Nitazoxanide Meta
Curcumin Meta Nitric Oxide Meta
Ensovibep Meta Paxlovid Meta
Famotidine Meta Peg.. Lambda Meta
Favipiravir Meta Povidone-Iod.. Meta
Fluvoxamine Meta Quercetin Meta
Hydroxychlor.. Meta Remdesivir Meta
Iota-carragee.. Meta
Ivermectin Meta Zinc Meta

Other Treatments Global Adoption
Loading...
Exercise for COVID-19: real-time meta analysis of 55 studies
Covid Analysis, June 2023
https://c19early.org/exmeta.html
 
0 0.5 1 1.5+ All studies 41% 55 1,791,863 Improvement, Studies, Patients Relative Risk Mortality 50% 17 1,483,440 Ventilation 46% 2 43,773 ICU admission 41% 4 708,149 Hospitalization 36% 16 893,621 Cases 22% 20 209,306 Peer-reviewed 41% 53 1,785,184 Prophylaxis 41% 54 1,791,424 Late 47% 1 439 Exercise for COVID-19 c19early.org/ex Jun 2023 Favorsexercise Favorsinactivity after exclusions
Statistically significant improvements are seen for mortality, ventilation, ICU admission, hospitalization, progression, recovery, and cases. 41 studies from 41 independent teams in 20 different countries show statistically significant improvements in isolation (31 for the most serious outcome).
Meta analysis using the most serious outcome reported shows 41% [34‑47%] improvement. Results are similar after exclusions and similar for peer-reviewed studies.
Results are robust — in exclusion sensitivity analysis 41 of 55 studies must be excluded to avoid finding statistically significant efficacy in pooled analysis.
Results are consistent with the overall risk of all cause mortality based on cardiorespiratory fitness — [Laukkanen] show RR 0.55 [0.50-0.61] for the top vs. bottom tertiles.
0 0.5 1 1.5+ All studies 41% 55 1,791,863 Improvement, Studies, Patients Relative Risk Mortality 50% 17 1,483,440 Ventilation 46% 2 43,773 ICU admission 41% 4 708,149 Hospitalization 36% 16 893,621 Cases 22% 20 209,306 Peer-reviewed 41% 53 1,785,184 Prophylaxis 41% 54 1,791,424 Late 47% 1 439 Exercise for COVID-19 c19early.org/ex Jun 2023 Favorsexercise Favorsinactivity after exclusions
Most studies analyze exercise/physical activity levels before infection, comparing regular/moderate exercise and lower/no exercise. Risk may increase with more extreme activity levels.
No treatment, vaccine, or intervention is 100% effective and available. All practical, effective, and safe means should be used based on risk/benefit analysis.
All data to reproduce this paper and sources are in the appendix. Other meta analyses for exercise can be found in [Ezzatvar, Li, Liu, Rahmati, Sittichai], showing significant improvements for mortality, ICU admission, hospitalization, severity, and cases.
Evolution of COVID-19 clinical evidence Exercise p<0.0000000001 Acetaminophen p=0.0000018 2020 2021 2022 2023 Effective Harmful c19early.org June 2023 meta analysis results (pooled effects) 100% 50% 0% -50%
Percentage improvement with increased activity levels (more)
All studies Studies Patients Authors
All studies41% [34‑47%]
****
55 1,791,863 495
Mortality50% [39‑60%]
****
17 1,483,440 161
HospitalizationHosp.36% [28‑43%]
****
16 893,621 116
Cases22% [11‑32%]
***
20 209,306 230
Highlights
Exercise reduces risk for COVID-19 with very high confidence for mortality, ICU admission, hospitalization, cases, and in pooled analysis, and low confidence for ventilation, progression, and recovery.
We show traditional outcome specific analyses and combined evidence from all studies.
Real-time updates and corrections, transparent analysis with all results in the same format, consistent protocol for 51 treatments.
A
0 0.25 0.5 0.75 1 1.25 1.5 1.75 2+ Fernandez 47% 0.53 [0.29-0.90] death 16/201 62/238 Improvement, RR [CI] Treatment Control Tau​2 = 0.00, I​2 = 0.0%, p = 0.014 Late treatment 47% 0.53 [0.29-0.90] 16/201 62/238 47% improvement Hamer 28% 0.72 [0.61-0.87] hosp. n/a n/a Improvement, RR [CI] Treatment Control Brawner 74% 0.26 [0.11-0.58] hosp. n/a n/a Tret'yakov 98% 0.02 [0.00-0.27] severe case 0/27 53/266 Gao -105% 2.05 [1.39-3.02] cases case control Ho 35% 0.65 [0.48-0.89] hosp. 213/123,588 59/14,887 Halabchi 89% 0.11 [0.01-1.46] death 0/249 79/4,445 Zhang 26% 0.74 [0.48-1.14] death n/a n/a Li 81% 0.19 [0.05-0.74] severe case n/a n/a per SD increase Tavakol 69% 0.31 [0.10-1.02] severe case 3/64 19/124 Yates 45% 0.55 [0.38-0.79] death 72/163,912 62/30,119 COVIDENCE UK Holt 17% 0.83 [0.63-1.09] cases 15,227 (all patients) Cho 53% 0.47 [0.26-0.87] death case control Sallis 59% 0.41 [0.22-0.76] death 11/3,118 170/6,984 Christensen 63% 0.37 [0.16-0.85] death 543 (n) 529 (n) Latorre-Román 76% 0.24 [0.05-1.04] hosp. n/a n/a Marcus 42% 0.58 [0.48-0.71] symp. case 240/10,627 134/3,708 Yuan 91% 0.09 [0.01-1.65] death 0/61 6/103 Brandenburg -6% 1.06 [0.23-4.79] hosp. 102 (n) 39 (n) Bielik 30% 0.70 [0.40-1.21] mod. case 775 (n) 365 (n) af Geijerstam 50% 0.50 [0.31-0.81] death 318,902 (n) 336,271 (n) Lee 74% 0.26 [0.07-0.99] death 2/11,072 32/41,293 Maltagliati 52% 0.48 [0.25-0.87] hosp. n/a n/a Baynouna AlKetbi 98% 0.01 [0.00-0.44] death n/a n/a Ahmadi 30% 0.70 [0.54-0.89] death 160/232,613 112/95,221 Nguyen 20% 0.80 [0.72-0.88] symp. case 904/2,836 483/1,111 Lin 47% 0.53 [0.12-2.33] cases n/a n/a de Souza 73% 0.27 [0.07-1.06] ventilation 3/611 6/327 Mohsin 19% 0.81 [0.66-0.99] severe case 86/258 224/544 Ekblom-Bak 48% 0.52 [0.30-0.92] severe case n/a n/a Lengelé 74% 0.26 [0.07-0.80] cases 23/229 4/12 Saadeh 9% 0.91 [0.56-1.43] symp. case 362 (n) 225 (n) Hamrouni 29% 0.71 [0.55-0.92] death 138/106,006 109/47,827 Huang 47% 0.53 [0.23-1.22] severe case 7/74 16/90 Hamdan 16% 0.84 [0.49-1.39] hosp. 22/128 37/172 Steenkamp 42% 0.58 [0.50-0.68] death 29,469 (n) 13,366 (n) Gilley -42% 1.42 [0.60-3.35] cases 172/1,917 5/79 Almansour 6% 0.94 [0.40-1.47] cases 35/71 38/71 Beydoun 43% 0.57 [0.32-1.01] cases 1,710 (n) 448 (n) Salgado-Aranda 83% 0.17 [0.05-0.56] death 4/223 41/297 Paul 38% 0.62 [0.30-1.20] PASC 1,811 (all patients) LONG COVID Kontopoulou 66% 0.34 [0.24-0.47] recov. time 42 (n) 24 (n) Malisoux 63% 0.37 [0.14-0.98] progression 115 (n) 108 (n) Antunes 80% 0.20 [0.03-1.41] ICU 1/14 9/25 Tsuzuki 56% 0.44 [0.36-0.52] severe case 3,340 (n) 1,528 (n) Reis 41% 0.59 [0.26-1.26] hosp. 9/241 29/305 Pływaczewska-J.. 11% 0.89 [0.72-1.11] m/s case 490 (n) 1,357 (n) Pitanga 33% 0.67 [0.45-1.01] cases 1,469 (n) 1,552 (n) Green 42% 0.58 [0.53-0.63] cases 1,267/11,144 16,198/101,931 Kapusta 71% 0.29 [0.20-0.43] severe case 181 (n) 387 (n) Young 74% 0.26 [0.20-0.33] death 11,279 (n) 29,099 (n) Wang 11% 0.89 [0.75-1.06] PASC 274/691 283/594 LONG COVID Park 26% 0.74 [0.53-1.04] death n/a n/a Sanchez 54% 0.46 [0.38-0.55] symp. case n/a n/a Cardoso 73% 0.27 [0.17-0.45] severe case case control Tau​2 = 0.09, I​2 = 84.1%, p < 0.0001 Prophylaxis 41% 0.59 [0.53-0.66] 3,646/1,038,553 18,208/735,833 41% improvement All studies 41% 0.59 [0.53-0.66] 3,662/1,038,754 18,270/736,071 41% improvement 55 exercise COVID-19 studies c19early.org/ex Jun 2023 Tau​2 = 0.09, I​2 = 83.8%, p < 0.0001 Effect extraction pre-specified(most serious outcome, see appendix) Favors exercise Favors inactivity
0 0.25 0.5 0.75 1 1.25 1.5 1.75 2+ Fernandez 47% death Relative Risk [CI] Tau​2 = 0.00, I​2 = 0.0%, p = 0.014 Late treatment 47% 47% improvement Hamer 28% hospitalization Brawner 74% hospitalization Tret'yakov 98% severe case Gao -105% case Ho 35% hospitalization Halabchi 89% death Zhang 26% death Li 81% severe case per SD increase Tavakol 69% severe case Yates 45% death COVIDENCE UK Holt 17% case Cho 53% death Sallis 59% death Christensen 63% death Latorre-Román 76% hospitalization Marcus 42% symp. case Yuan 91% death Brandenburg -6% hospitalization Bielik 30% mod. case af Geijerstam 50% death Lee 74% death Maltagliati 52% hospitalization Baynouna AlKetbi 98% death Ahmadi 30% death Nguyen 20% symp. case Lin 47% case de Souza 73% ventilation Mohsin 19% severe case Ekblom-Bak 48% severe case Lengelé 74% case Saadeh 9% symp. case Hamrouni 29% death Huang 47% severe case Hamdan 16% hospitalization Steenkamp 42% death Gilley -42% case Almansour 6% case Beydoun 43% case Salgado-Aranda 83% death Paul 38% PASC LONG COVID Kontopoulou 66% recovery Malisoux 63% progression Antunes 80% ICU admission Tsuzuki 56% severe case Reis 41% hospitalization Pływaczewska-.. 11% mod./sev. case Pitanga 33% case Green 42% case Kapusta 71% severe case Young 74% death Wang 11% PASC LONG COVID Park 26% death Sanchez 54% symp. case Cardoso 73% severe case Tau​2 = 0.09, I​2 = 84.1%, p < 0.0001 Prophylaxis 41% 41% improvement All studies 41% 41% improvement 55 exercise COVID-19 studies c19early.org/ex Jun 2023 Tau​2 = 0.09, I​2 = 83.8%, p < 0.0001 Effect extraction pre-specifiedRotate device for details Favors exercise Favors inactivity
B
Loading..
C
Loading..
D
Loading..
Figure 1. A. Random effects meta-analysis. This plot shows pooled effects, see the specific outcome analyses for individual outcomes, and the heterogeneity section for discussion. Effect extraction is pre-specified, using the most serious outcome reported. For details of effect extraction see the appendix. B. Scatter plot showing the most serious outcome in all studies. The diamond shows the results of random effects meta-analysis. C. Results within the context of multiple COVID-19 treatments. 0.9% of 3,946 proposed treatments show efficacy [c19early.org]. D. Timeline of results in exercise studies. The marked dates indicate the time when efficacy was known with a statistically significant improvement of ≥10% from ≥3 studies for pooled outcomes and one or more specific outcome. Efficacy based on specific outcomes was delayed by 0.8 months, compared to using pooled outcomes.
We analyze all significant studies reporting COVID-19 outcomes as a function of physical activity levels. Search methods, inclusion criteria, effect extraction criteria (more serious outcomes have priority), all individual study data, PRISMA answers, and statistical methods are detailed in Appendix 1. We present random effects meta-analysis results for all studies, studies within each treatment stage, individual outcomes, peer-reviewed studies, and after exclusions.
Insufficient physical activity is a risk factor for many diseases and is common around the world [Guthold], as shown in Figure 2. [Guthold] found that prevalence in high-income countries was over twice as high, and has increased over time.
Figure 2. Low physical activity levels are common. Prevalence of insufficient physical activity around the world as of 2016, from [Guthold] (top: female, bottom: male).
For upper respiratory tract infections, research shows lower risk for moderate activity vs. a sedentary lifestyle, however risk may increase with more extreme activity levels [Nieman].
Table 1 summarizes the results for all studies, with different exclusions, and for specific outcomes. Figure 3, 4, 5, 6, 7, 8, 9, 10, and 11 show forest plots for random effects meta-analysis of all studies with pooled effects, mortality results, ventilation, ICU admission, hospitalization, progression, recovery, cases, and peer reviewed studies.
Table 1. Random effects meta-analysis for all studies, with different exclusions, and for specific outcomes. Results show the percentage improvement with increased activity levels and the 95% confidence interval. * p<0.05  *** p<0.001  **** p<0.0001.
Improvement Studies Patients Authors
All studies41% [34‑47%]
****
55 1,791,863 495
After exclusions40% [33‑46%]
****
51 1,790,538 463
Peer-reviewed studiesPeer-reviewed41% [34‑47%]
****
53 1,785,184 489
Mortality50% [39‑60%]
****
17 1,483,440 161
VentilationVent.46% [32‑57%]
****
2 43,773 18
ICU admissionICU41% [35‑47%]
****
4 708,149 32
HospitalizationHosp.36% [28‑43%]
****
16 893,621 116
Cases22% [11‑32%]
***
20 209,306 230
Loading..
Loading..
Figure 3. Random effects meta-analysis for all studies with pooled effects. This plot shows pooled effects, see the specific outcome analyses for individual outcomes, and the heterogeneity section for discussion. Effect extraction is pre-specified, using the most serious outcome reported. For details of effect extraction see the appendix.
Loading..
Loading..
Figure 4. Random effects meta-analysis for mortality results.
Loading..
Figure 5. Random effects meta-analysis for ventilation.
Loading..
Figure 6. Random effects meta-analysis for ICU admission.
Loading..
Figure 7. Random effects meta-analysis for hospitalization.
Loading..
Figure 8. Random effects meta-analysis for progression.
Loading..
Figure 9. Random effects meta-analysis for recovery.
Loading..
Figure 10. Random effects meta-analysis for cases.
Loading..
Figure 11. Random effects meta-analysis for peer reviewed studies. [Zeraatkar] analyze 356 COVID-19 trials, finding no significant evidence that preprint results are inconsistent with peer-reviewed studies. They also show extremely long peer-review delays, with a median of 6 months to journal publication. A six month delay was equivalent to around 1.5 million deaths during the first two years of the pandemic. Authors recommend using preprint evidence, with appropriate checks for potential falsified data, which provides higher certainty much earlier. Effect extraction is pre-specified, using the most serious outcome reported, see the appendix for details.
To avoid bias in the selection of studies, we analyze all non-retracted studies. Here we show the results after excluding studies with major issues likely to alter results, non-standard studies, and studies where very minimal detail is currently available. Our bias evaluation is based on analysis of each study and identifying when there is a significant chance that limitations will substantially change the outcome of the study. We believe this can be more valuable than checklist-based approaches such as Cochrane GRADE, which may underemphasize serious issues not captured in the checklists, overemphasize issues unlikely to alter outcomes in specific cases (for example, lack of blinding for an objective mortality outcome, or certain specifics of randomization with a very large effect size), or be easily influenced by potential bias. However, they can also be very high quality.
The studies excluded are as below. Figure 12 shows a forest plot for random effects meta-analysis of all studies after exclusions.
[Brawner], unadjusted results with no group details.
[de Souza], unadjusted results with no group details. Excluded results: mechanical ventilation.
[Huang], unadjusted results with no group details. Excluded results: severe case.
[Kontopoulou], unadjusted results with no group details.
[Mohsin], unadjusted results with no group details.
[Tret'yakov], unadjusted results with no group details.
[Yuan], excessive unadjusted differences between groups. Excluded results: death.
Loading..
Figure 12. Random effects meta-analysis for all studies after exclusions. This plot shows pooled effects, see the specific outcome analyses for individual outcomes, and the heterogeneity section for discussion. Effect extraction is pre-specified, using the most serious outcome reported. For details of effect extraction see the appendix.
More physically active people have reduced risk for COVID-19. Statistically significant improvements are seen for mortality, ventilation, ICU admission, hospitalization, progression, recovery, and cases. 41 studies from 41 independent teams in 20 different countries show statistically significant improvements in isolation (31 for the most serious outcome). Meta analysis using the most serious outcome reported shows 41% [34‑47%] improvement. Results are similar after exclusions and similar for peer-reviewed studies. Results are robust — in exclusion sensitivity analysis 41 of 55 studies must be excluded to avoid finding statistically significant efficacy in pooled analysis. Results are consistent with the overall risk of all cause mortality based on cardiorespiratory fitness — [Laukkanen] show RR 0.55 [0.50-0.61] for the top vs. bottom tertiles.
Most studies analyze exercise/physical activity levels before infection, comparing regular/moderate exercise and lower/no exercise. Risk may increase with more extreme activity levels.
0 0.5 1 1.5 2+ Mortality 50% Improvement Relative Risk ICU admission 40% Hospitalization 27% c19early.org/ex af Geijerstam et al. Exercise for COVID-19 Prophylaxis Does physical activity reduce risk for COVID-19? Prospective study of 1,559,187 patients in Sweden (Mar - Sep 2020) Lower mortality (p=0.0047) and ICU admission (p=0.00032) af Geijerstam et al., BMJ Open, doi:10.1136/bmjopen-2021-051316 Favors exercise Favors inactivity
[af Geijerstam] Prospective study of 1,559,187 men in Sweden with cardiorespiratory fitness levels measured on military conscription, showing high cardiorespiratory fitness associated with lower risk of COVID-19 hospitalization, ICU admission, and death.
0 0.5 1 1.5 2+ Mortality 30% Improvement Relative Risk c19early.org/ex Ahmadi et al. Exercise for COVID-19 Prophylaxis Does physical activity reduce risk for COVID-19? Retrospective 327,834 patients in the United Kingdom Lower mortality with higher activity levels (p=0.0052) Ahmadi et al., Brain, Behavior, and Immunity, doi:10.1016/j.bbi.2021.04.022 Favors exercise Favors inactivity
[Ahmadi] Retrospective 468,569 adults in the UK, showing no significant difference in COVID-19 mortality based on diet quality, however significantly lower mortality was seen with higher diet quality for pneumonia and infectious diseases.
0 0.5 1 1.5 2+ Case 6% Improvement Relative Risk c19early.org/ex Almansour et al. Exercise for COVID-19 Prophylaxis Does physical activity reduce risk for COVID-19? Retrospective 142 patients in Saudi Arabia (April - June 2020) No significant difference in cases Almansour et al., J. Multidisciplinary Healthcare, doi:10.2147/JMDH.S352753 Favors exercise Favors inactivity
[Almansour] Retrospective 142 patients in Saudi Arabia, showing no significant difference in cases with physical activity.
0 0.5 1 1.5 2+ ICU admission 80% Improvement Relative Risk CT >50% 40% CT 25-50% 73% Hospitalization time 43% Disease duration 26% c19early.org/ex Antunes et al. Exercise for COVID-19 Prophylaxis Does physical activity reduce risk for COVID-19? Retrospective 39 patients in Brazil (September - December 2020) Shorter hospitalization with higher activity levels (p=0.03) Antunes et al., Sport Sciences for Health, doi:10.1007/s11332-022-00948-7 Favors exercise Favors inactivity
[Antunes] Retrospective 39 hospitalized COVID-19 survivors >60 years old, showing shorter hospitalization for patients with active lifestyles before COVID-19 symptoms.
0 0.5 1 1.5 2+ Mortality 98% Improvement Relative Risk c19early.org/ex Baynouna AlKetbi et al. Exercise Prophylaxis Does physical activity reduce risk for COVID-19? Retrospective study in United Arab Emirates Lower mortality with higher activity levels (p=0.049) Baynouna AlKetbi et al., J. Epidemiology and Glo.., doi:10.1007/s44197-021-00006-4 Favors exercise Favors inactivity
[Baynouna AlKetbi] Retrospective 234 COVID-19 cases in the United Arab Emirates, showing lower risk of mortality with increased physical activity.
0 0.5 1 1.5 2+ Case, >1/week vs. none 43% Improvement Relative Risk Case, 1-4/mon vs. none 62% c19early.org/ex Beydoun et al. Exercise for COVID-19 Prophylaxis Does physical activity reduce risk for COVID-19? Retrospective 2,158 patients in the USA Fewer cases with higher activity levels (not stat. sig., p=0.055) Beydoun et al., American J. Infection Control, doi:10.1016/j.ajic.2022.02.021 Favors exercise Favors inactivity
[Beydoun] Retrospective 2,830 people in the USA, showing lower risk of COVID-19 with a history of moderate/vigorous exercise.
0 0.5 1 1.5 2+ Moderate case 30% Improvement Relative Risk Case -9% c19early.org/ex Bielik et al. Exercise for COVID-19 Prophylaxis Does physical activity reduce risk for COVID-19? Retrospective 1,140 patients in Slovakia (December - December 2020) Fewer moderate/severe cases with higher activity levels (not stat. sig., p=0.1) Bielik et al., Int. J. Environmental Research an.., doi:10.3390/ijerph18137158 Favors exercise Favors inactivity
[Bielik] Retrospective 1,544 participants in Slovakia, showing a lower risk of more severe COVID-19 for physically active participants, without statistical significance.
0 0.5 1 1.5 2+ Hospitalization, PA -6% Improvement Relative Risk Hospitalization, CRF 78% Hospitalization, CRF (b) 64% Severe case, PA 35% Severe case, CRF 24% c19early.org/ex Brandenburg et al. Exercise for COVID-19 Prophylaxis Does physical activity reduce risk for COVID-19? Retrospective 211 patients in multiple countries Lower severe cases with higher activity levels (not stat. sig., p=0.3) Brandenburg et al., J. Physical Activity and Hea.., doi:10.1123/jpah.2020-0817 Favors exercise Favors inactivity
[Brandenburg] Retrospective 263 COVID+ patients, showing lower hospitalization with higher self-reported cardiorespiratory fitness, but no significant differences for physical activity. Participants in the study were healthier and more fit than the general population.
0 0.5 1 1.5 2+ Hospitalization 74% unadjusted Improvement Relative Risk c19early.org/ex Brawner et al. Exercise for COVID-19 Prophylaxis Does physical activity reduce risk for COVID-19? Retrospective study in the USA (February - May 2020) Lower hospitalization with higher activity levels (p=0.0012) Brawner et al., Mayo Clinic Proceedings, doi:10.1016/j.mayocp.2020.10.003 Favors exercise Favors inactivity
[Brawner] Retrospective 246 COVID-19 patients in the USA, showing the risk of hospitalization inversely associated with maximal exercise capacity. Adjusted results are only provided for MET as a continuous variable.
0 0.5 1 1.5 2+ Severe case 73% Improvement Relative Risk c19early.org/ex Cardoso et al. Exercise for COVID-19 Prophylaxis Does physical activity reduce risk for COVID-19? Retrospective 614 patients in Brazil (April 2020 - February 2022) Lower severe cases with higher activity levels (p<0.000001) Cardoso et al., Medicina Clínica, doi:10.1016/j.medcli.2023.04.031 Favors exercise Favors inactivity
[Cardoso] Case control study with 307 severe COVID-19 ICU patients and 307 matched COVID-19 outpatients in Brazil, showing significantly higher risk of severe cases with low physical activity.
0 0.5 1 1.5 2+ Mortality 53% Improvement Relative Risk Case 10% c19early.org/ex Cho et al. Exercise for COVID-19 Prophylaxis Does physical activity reduce risk for COVID-19? Retrospective 97,123 patients in South Korea Lower mortality (p=0.014) and fewer cases (p<0.0001) Cho et al., J. Clinical Medicine, doi:10.3390/jcm10071539 Favors exercise Favors inactivity
[Cho] Retrospective 6,288 COVID+ patients and 125,772 matched controls in South Korea, showing significantly lower risk of COVID-19 infection and mortality with higher physical activity.
0 0.5 1 1.5 2+ Mortality 63% Improvement Relative Risk Case 23% c19early.org/ex Christensen et al. Exercise for COVID-19 Prophylaxis Does physical activity reduce risk for COVID-19? Prospective study of 1,072 patients in the United Kingdom (Mar - Jul 2020) Lower mortality with higher activity levels (p=0.019) Christensen et al., PLOS ONE, doi:10.1371/journal.pone.0250508 Favors exercise Favors inactivity
[Christensen] Prospective study of 2,690 adults in the UK Biobank showing lower cardiorespiritory fitness associated with COVID-19 mortality.
0 0.5 1 1.5 2+ Ventilation 73% unadjusted Improvement Relative Risk Hospitalization 34% c19early.org/ex de Souza et al. NCT04396353 Exercise Prophylaxis Does physical activity reduce risk for COVID-19? Retrospective 938 patients in Brazil (June - August 2020) Lower hospitalization with higher activity levels (p=0.046) de Souza et al., J. Science and Medicine in Sport, doi:10.1016/j.jsams.2021.05.011 Favors exercise Favors inactivity
[de Souza] Retrospective survey of 938 COVID-19 recovered patients in Brazil, showing lower hospitalization with physical activity. NCT04396353.
0 0.5 1 1.5 2+ Severe case 48% Improvement Relative Risk c19early.org/ex Ekblom-Bak et al. Exercise for COVID-19 Prophylaxis Does physical activity reduce risk for COVID-19? Retrospective study in Sweden Lower severe cases with higher activity levels (p=0.023) Ekblom-Bak et al., Int. J. Behavioral Nutrition .., doi:10.1186/s12966-021-01198-5 Favors exercise Favors inactivity
[Ekblom-Bak] Retrospective 857 severe COVID-19 cases and matched controls in Sweden, showing lower risk of severe COVID-19 with higher cardiorespiratory fitness.
0 0.5 1 1.5 2+ Mortality 47% Improvement Relative Risk c19early.org/ex Fernandez et al. Exercise for COVID-19 LATE TREATMENT Is late treatment with exercise beneficial for COVID-19? Retrospective 439 patients in Chile Lower mortality with exercise (p=0.018) Fernandez et al., J. Applied Physiology, doi:10.1152/japplphysiol.00544.2022 Favors exercise Favors inactivity
[Fernandez] Retrospective 439 severe COVID-19 hospitalized patients with hypertension, 201 receiving a supervised exercise program, showing significantly lower mortality with exercise. Exercise included of aerobic, breathing, and musculoskeletal exercises, 3 to 4 times per week. There were significantly more control patients on beta-adrenergic blockers and thiazide diuretics.

There are many possible mechanisms of action, including improved circulation, stress reduction, hormone regulation, improved sleep, increased antioxidant levels, and increased nitric oxide levels in the respiratory system. Over-exercising may be detrimental and lead to impaired immune function.
0 0.5 1 1.5 2+ Case -105% Improvement Relative Risk c19early.org/ex Gao et al. Exercise for COVID-19 Prophylaxis Does physical activity reduce risk for COVID-19? Retrospective 315 patients in China (February - March 2020) More cases with higher activity levels (p=0.00031) Gao et al., PLOS ONE, doi:10.1371/journal.pone.0241540 Favors exercise Favors inactivity
[Gao] Case control study in China with 105 cases and 210 matched controls, showing COVID-19 cases associated with physical activity ≥5 times per week. Authors note that people may choose gyms for exercise in winter, leading to higher exposure risk.
0 0.5 1 1.5 2+ Case -42% unadjusted Improvement Relative Risk c19early.org/ex Gilley et al. NCT04766788 Exercise Prophylaxis Does physical activity reduce risk for COVID-19? Retrospective 1,996 patients in the USA (September - December 2020) More cases with higher activity levels (not stat. sig., p=0.55) Gilley et al., JMIR Mental Health, doi:10.2196/34645 Favors exercise Favors inactivity
[Gilley] Retrospective survey of 1,997 college students in the USA, showing no significant difference in COVID-19 cases with exercise in unadjusted results.
0 0.5 1 1.5 2+ Case 42% Improvement Relative Risk c19early.org/ex Green et al. Exercise for COVID-19 Prophylaxis Does physical activity reduce risk for COVID-19? Retrospective 113,075 patients in Israel (February - December 2020) Fewer cases with higher activity levels (p<0.000001) Green et al., European J. General Practice, doi:10.1080/13814788.2022.2138855 Favors exercise Favors inactivity
[Green] Retrospective 113,075 people in Israel, showing lower risk of COVID-19 cases with physical activity and a dose dependent response.
0 0.5 1 1.5 2+ Mortality 89% Improvement Relative Risk Hospitalization 28% c19early.org/ex Halabchi et al. Exercise for COVID-19 Prophylaxis Does physical activity reduce risk for COVID-19? Retrospective 4,694 patients in Iran Lower hospitalization with higher activity levels (p=0.044) Halabchi et al., J. Physical Activity and Health, doi:10.1123/jpah.2020-0392 Favors exercise Favors inactivity
[Halabchi] Retrospective 4,694 COVID-19 patients in Iran, showing lower risk of hospitalization and mortality with regular sports participation.
0 0.5 1 1.5 2+ Hospitalization 16% Improvement Relative Risk c19early.org/ex Hamdan et al. Exercise for COVID-19 Prophylaxis Does physical activity reduce risk for COVID-19? Retrospective 300 patients in Palestine Lower hospitalization with higher activity levels (not stat. sig., p=0.53) Hamdan et al., J. Int. Medical Research, doi:10.1177/03000605211064405 Favors exercise Favors inactivity
[Hamdan] Retrospective 300 participants in Palestine, showing lower risk of hospitalization with physical activity, without statistical significance.
0 0.5 1 1.5 2+ Hospitalization 28% Improvement Relative Risk Hospitalization (b) 34% c19early.org/ex Hamer et al. Exercise for COVID-19 Prophylaxis Does physical activity reduce risk for COVID-19? Retrospective study in the United Kingdom Lower hospitalization with higher activity levels (p=0.0004) Hamer et al., Brain, Behavior, and Immunity, doi:10.1016/j.bbi.2020.05.059 Favors exercise Favors inactivity
[Hamer] UK Biobank retrospective analysis of 387,109 people, showing lower risk of COVID-19 hospitalization with physical activity.
0 0.5 1 1.5 2+ Mortality 29% Improvement Relative Risk c19early.org/ex Hamrouni et al. Exercise for COVID-19 Prophylaxis Does physical activity reduce risk for COVID-19? Prospective study of 153,833 patients in the United Kingdom Lower mortality with higher activity levels (p=0.0093) Hamrouni et al., BMJ Open, doi:10.1136/bmjopen-2021-055003 Favors exercise Favors inactivity
[Hamrouni] Prospective UK Biobank analysis, showing a history of low physical activity associated with COVID-19 mortality.
0 0.5 1 1.5 2+ Hospitalization 35% Improvement Relative Risk c19early.org/ex Ho et al. Exercise for COVID-19 Prophylaxis Does physical activity reduce risk for COVID-19? Retrospective 138,475 patients in the United Kingdom Lower hospitalization with higher activity levels (p=0.007) Ho et al., BMJ Open, doi:10.1136/bmjopen-2020-040402 Favors exercise Favors inactivity
[Ho] UK Biobank retrospective 235,928 participants using walking pace as a proxy for physical fitness, showing lower risk of COVID-19 hospitalization with an average vs. slow walking pace.
0 0.5 1 1.5 2+ Case 17% Improvement Relative Risk c19early.org/ex Holt et al. NCT04330599 COVIDENCE UK Exercise Prophylaxis Does physical activity reduce risk for COVID-19? Prospective study of 15,227 patients in the United Kingdom (May 2020 - Feb 2021) Fewer cases with higher activity levels (not stat. sig., p=0.18) Holt et al., Thorax, doi:10.1136/thoraxjnl-2021-217487 Favors exercise Favors inactivity
[Holt] Prospective survey-based study with 15,227 people in the UK, showing reduced risk of COVID-19 cases with lower impact physical activity. NCT04330599. COVIDENCE UK.
0 0.5 1 1.5 2+ Severe case 47% unadjusted Improvement Relative Risk Severe case (b) 8% unadjusted Case 66% c19early.org/ex Huang et al. Exercise for COVID-19 Prophylaxis Does physical activity reduce risk for COVID-19? Retrospective 164 patients in China (February - March 2020) Fewer cases with higher activity levels (p=0.0035) Huang et al., Nature and Science of Sleep, doi:10.2147/NSS.S263488 Favors exercise Favors inactivity
[Huang] Retrospective 164 COVID-19 patients and 188 controls in China, showing lower risk of cases with regular exercise.
0 0.5 1 1.5 2+ Severe case 71% Improvement Relative Risk c19early.org/ex Kapusta et al. NCT05018052 Exercise Prophylaxis Does physical activity reduce risk for COVID-19? Retrospective 568 patients in Poland (March - August 2020) Lower severe cases with higher activity levels (p=0.001) Kapusta et al., J. Infection and Public Health, doi:10.1016/j.jiph.2022.12.008 Favors exercise Favors inactivity
[Kapusta] Retrospective 568 convalescent COVID-19 patients in Poland, showing lower risk of severe cases with regular physical activity in the 3 months before COVID-19.
0 0.5 1 1.5 2+ Recovery time 66% Improvement Relative Risk Dyspnea after hospitalizat.. 67% c19early.org/ex Kontopoulou et al. Exercise for COVID-19 Prophylaxis Does physical activity reduce risk for COVID-19? Retrospective 66 patients in Greece (November - December 2020) Faster recovery with higher activity levels (p<0.000001) Kontopoulou et al., J. Personalized Medicine, doi:10.3390/jpm12040645 Favors exercise Favors inactivity
[Kontopoulou] Retrospective 66 hospitalized COVID-19 patients in Greece, showing significantly improved recovery with a history of exercise in unadjusted results. Exercise after hospitalization was also associated with lower levels of dyspnea one month post hospitalization.
0 0.5 1 1.5 2+ Hospitalization 76% Improvement Relative Risk Hospitalization (b) 87% c19early.org/ex Latorre-Román et al. Exercise for COVID-19 Prophylaxis Does physical activity reduce risk for COVID-19? Retrospective study in Spain Lower hospitalization with higher activity levels (not stat. sig., p=0.05) Latorre-Román et al., Research in Sports Medicine, doi:10.1080/15438627.2021.1937166 Favors exercise Favors inactivity
[Latorre-Román] Retrospective 420 people in Spain, showing lower risk of COVID-19 hospitalization with a history of physical activity.
0 0.5 1 1.5 2+ Mortality 74% Improvement Relative Risk Severe case 58% Case 16% c19early.org/ex Lee et al. Exercise for COVID-19 Prophylaxis Does physical activity reduce risk for COVID-19? Retrospective 52,365 patients in South Korea (Jan - Jul 2020) Lower mortality (p=0.046) and severe cases (p=0.03) Lee et al., British J. Sports Medicine, doi:10.1136/bjsports-2021-104203 Favors exercise Favors inactivity
[Lee] Retrospective 212,768 adults in South Korea, showing lower risk of COVID-19 cases, severity, and mortality with physical activity. Notably, results for aerobic and muscle strengthening activities combined were much better than results for either one in isolation.
0 0.5 1 1.5 2+ Case 74% Improvement Relative Risk c19early.org/ex Lengelé et al. Exercise for COVID-19 Prophylaxis Does physical activity reduce risk for COVID-19? Prospective study of 241 patients in Belgium (Mar 2020 - Apr 2021) Fewer cases with higher activity levels (p=0.028) Lengelé et al., Aging Clinical and Experimental .., doi:10.1007/s40520-021-01991-z Favors exercise Favors inactivity
[Lengelé] Analysis of 241 adults >65yo in Belgium, showing lower risk of COVID-19 with a history of physical activity.
0 0.5 1 1.5 2+ Severe case 81% Improvement Relative Risk Hospitalization 56% c19early.org/ex Li et al. Exercise for COVID-19 Prophylaxis Does physical activity reduce risk for COVID-19? Retrospective study in the United Kingdom Lower severe cases with higher activity levels (p=0.02) Li et al., BMC Medical Genomics, doi:10.1186/s12920-021-00887-1 Favors exercise Favors inactivity
[Li (B)] Mendelian randomization study showing lower risk of severe COVID-19 with physical activity.
0 0.5 1 1.5 2+