When the worst illness that could affect us was the common cold in winter, exercising while sick was a lot easier to tackle.

Covid-19 has changed all that. By introducing a new set of post-illness symptoms and conditions to deal with it has changed the approach to getting back to fitness after contracting the disease. At the same time, it has created an opportunity to re-examine the protocols that apply when getting back into fitness after a long lay-off and getting back into fitness after illness that isn’t Covid-19.

There are some overlaps. There are a lot of differences too. So, let’s start with what are the easiest ones to tackle first.

Getting Back Into Fitness After A Long Lay-off or Illness

Provided the illness in question is not Covid-19 the approach to getting back into fitness afterwards is virtually identical with the approach to getting back into fitness after a long lay-off.

• Continue to exercise but reduce the duration and intensity. Consider that coming back from illness or a long lay-off from training creates a mental disconnect. In your mind’s eye you see yourself performing just as you did before you got ill or stopped training. Now you want to just get back in and pick-up where you left off. Unfortunately, that’s a recipe for disaster. The Dallas Study ^[1] in 1966 showed that three weeks of inactivity in bed was enough to make fit, healthy, 20-year-olds physically age 40 years. This is no different. Getting back after illness or lay-off is a process that needs to gradually help your body recover the skills and strength it had before you stopped.
• Be your own coach. If you were an elite athlete getting back to fitness after some time you would have a coach devise a training program for you that would be designed to help you strengthen muscles that have been de-strengthened by your absence from training, and help you re-acquire your aerobic and cardiovascular fitness. Usually, when you do get back to fitness there is no coach. This means you need to be your own best counselor and advocate. Contain your impatience and plan to get back into shape in a gradual progression of exercise intensity and duration that’s safe for you.
• Give yourself adequate recovery time. It doesn’t matter what you could do before you became ill or stopped training. Now that you are back into training you are feeling better and naturally you will experience impatience in getting back where you were before. This is where you need to be smart. Listen to your body and make sure you have enough time to recover between training sessions and you’re getting enough sleep to help you repair tissue damage and build muscle.
• Devise small tests to gauge your progress. As you progress, devise small tests by upping the intensity of your training in short 2-3 minute long bursts to help you see where you are in relation to where your past fitness level was. This will give you a clear idea of how to better structure your training for a safe return to fitness.

Coming Back To Training After Covid-19

By all accounts Covid-19 is not just a respiratory disease^[3] it is also a multi-organ inflammatory one. ^[4] To add to this it seems to affect different people differently^[5] based upon such a wide variety of factors like sex, age, genetic background, past health history and environmental conditions.

This makes it difficult to recover from quickly and requires a much more gradual return to physical activity than most other forms of disease. Everything we know so far about athletes recovering from Covid-19^[6] suggests that recovery has to take place in a rigorously structured way that stretches over months rather than weeks and closely monitors performance.

If you had Covid-19 and are now getting back to fitness the general guidelines are:

• Reduce exercise intensity and duration. The suggestion is that if you had Covid-19 lightly you should start at less than 50% of your usual physical exercise intensity and duration. A quarter or less if you had it badly. 
• Get your heart checked. Because the heart muscle is affected after contracting Covid-19^[7] getting your heart checked before you start to exercise again is a really good idea. 
• If symptoms return stop exercising. If you experience unusual levels of fatigue, have breathing difficulties or feel confused, stop exercising. Wait for the symptoms to subside before you can start your return to physical fitness from the beginning. 
• Focus on your breathing. Covid-19 affects many key parts of the body but the lungs, arguably, are affected the most. Work on breathing deeply and evenly, even when you’re not exercising, to give your cardiovascular system the best possible chance to recover. 
• Adjust your training to your condition. Closely monitor your body and its responses. Adjust everything you do depending on the feedback your body gives you. Professional athletes who came back from Covid-19 infection have taken anywhere between one and six months to get back to normal. Patience and perseverance are key here but so are caution and vigilance. 
• Keep a training diary. Don’t rely on memory. To better help you plan your progression and strategize your training keep a detailed diary of days, dates, exercises you did and the outcome.

Summary

Getting back to fitness after illness or lay-off or even after Covid-19 requires a structured approach that eases you back into physical training and helps you make small gains, constantly. Never rush. Never take shortcuts. Always listen to your body.

References

1. TimeMcGavock JM, Hastings JL, Snell PG, et al. A forty-year follow-up of the Dallas Bed Rest and Training study: the effect of age on the cardiovascular response to exercise in men. J Gerontol A Biol Sci Med Sci. 2009;64(2):293-299. doi:10.1093/gerona/gln025 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2655009/
2. McGuire DK, Levine BD, Williamson JW, Snell PG, Blomqvist CG, Saltin B, Mitchell JH. A 30-year follow-up of the Dallas Bedrest and Training Study: I. Effect of age on the cardiovascular response to exercise. Circulation. 2001 Sep 18;104(12):1350-7. PMID: 11560849. https://pubmed.ncbi.nlm.nih.gov/11560849/
3. Kathleen Murphy, MD . SARS CoV-2 Detection From Upper and Lower Respiratory Tract Specimens. Chest Journal, VOLUME 158, ISSUE 5, P1804-1805, NOVEMBER 01, 2020. https://doi.org/10.1016/j.chest.2020.07.061
4. COVID-19: Pediatric Research Immune Network on SARS-CoV-2 and MIS-C (PRISM) https://clinicaltrials.gov/ct2/show/NCT04588363
5. Sette, A., Crotty, S. Pre-existing immunity to SARS-CoV-2: the knowns and unknowns. Nat Rev Immunol 20, 457–458 (2020). https://doi.org/10.1038/s41577-020-0389-z
6. Metzl, J.D., McElheny, K., Robinson, J.N. et al. Considerations for Return to Exercise Following Mild-to-Moderate COVID-19 in the Recreational Athlete. HSS Jrnl 16, 102–107 (2020). https://doi.org/10.1007/s11420-020-09777-1
7. Puntmann VO, Carerj ML, Wieters I, et al. Outcomes of Cardiovascular Magnetic Resonance Imaging in Patients Recently Recovered From Coronavirus Disease 2019 (COVID-19). JAMA Cardiol. 2020;5(11):1265–1273. doi:10.1001/jamacardio.2020.3557 https://jamanetwork.com/journals/jamacardiology/fullarticle/2768916