Working Out While Sick: These Symptoms Mean You Should Skip Your Workout Today

Learn how training, recovery, and immune resilience are connected. Understand the role of exercise in immune function and explore more about working out when feeling sick for lasting health benefits.

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By Staff Writer
Lucia Gcingca
Edited by Lucia Gcingca

Published March 6, 2024.

A woman taking a break on a running trail - Feeling Sick? These Symptoms Mean You Should Skip Your Workout Today

We've all weighed the costs and benefits of working out when sickMy throat hurts, so I'll stick to weights and avoid heavy breathing. Or, maybe a good sweat will break this fever. Oftentimes, it just boils down to, yeah, I feel like crap, but I have a plan I have to stick to. So we compromise and try to push through our workouts, even though we’re suffering (more than usual). After all, what doesn't kill you makes you stronger, right?

Well, sometimes, it can do more harm than good. Here's some advice to help you decide whether skipping your workout is a good call.

*Check with your healthcare practitioner if you have specific questions or concerns. 

Working out when feeling sick: Exercise and your immune system

First, let’s go over how your immune system relates to training and recovery

Impact of exercise-induced stress

Exercise puts different types of stress on our bodies, typically physical. Take weight training, for example; when you perform heavy squats, you exert physical stress on your muscles, which damages them at the cellular level. Your body then mounts an inflammatory response, which routes oxygen, nutrients, and immune cells to your muscles to kick off the repair process.

Understanding Biomarkers: hs-CRP and Creatine Kinase

It's this process that can cause elevated levels of hs-CRPa biomarker for total body inflammation, and creatine kinase, an indicator of muscle breakdown, after an especially tough workout.

» See how beetroot juice can enhance your athletic performance

White Blood Cells and Exercise: Boosting Your Body's Defenses

In addition to mobilizing immune cells to our muscles, exercise has also been shown to affect our overall levels of white blood cells (WBC). Certain types of interval training increase WBC in the body, and moderate-to-intense training can help optimize types of WBC known to fight viral and bacterial infections. [1, 2]

So don't be too alarmed if you see increases in this biomarker after a change in your training routine. Think of it as immune system training; it's through this mechanism that exercise can help build a strong immune system.

Did you know?

There’s evidence that those who exercise regularly have lower chances of catching the common cold than those who don't. [3]

A blue poster with a bunch of food on it  - Feeling Sick? These Symptoms Mean You Should Skip Your Workout Today

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Should I work out if I feel sick?

Well, now you know that exercise can induce elevated inflammation levels and, in turn, WBC numbers. But, if we’re sick on top of this, our bodies might not be able to respond to both exercise-induced inflammation and that caused by a sickness. Therefore, our ability to mount a proper immune response to fight infections is severely inhibited.

Of course, we know it can be hard for some people to weigh a day of training with a day in bed. So, by following some simple guidelines about training when sick, you can still get in your workout and get rid of the runny nose at the same time.

Guidelines for exercising when sick

When it's ok to exercise if you're feeling sick

Generally, if you’re experiencing symptoms “above the neck,” taking part in mild exercise is okay. These include:

  • Light cold
  • Runny nose
  • Sneezing
  • Minor sore throat

Modifications for working out while feeling sick

In my experience, a light training day can help open nasal passages and clear out congestion—but do consider some modifications:

  • Reduce training intensity and duration: Long and intense workouts can suppress the immune system and make symptoms worse. [4]
  • Avoid inverted movements: Handstand, pushups, or GHD sit-ups, which can put more unwanted pressure on your head.
  • Scale back on lifting heavy weights: Even though heavy weightlifting doesn’t get you out of breath, it requires a lot of your body's recovery resources – which you should conserve for fighting whatever is making you ill. 

» Uncover the importance of eating before a workout

When it's best to skip the workout if you're feeling sick

If you’re feeling worse than described above, consider putting the sneakers away. It’s best that you rest and allow your body the recovery it needs to start feeling better if your symptoms are “below the neck,” such as:

  • Chest congestion
  • Heavy coughing
  • Upset stomach

Exercising with a fever can be risky

If you have a fever or flu-like symptoms, participating in any exercise can be very dangerous. Fevers can decrease muscle strength, impair coordination, and increase dehydration. [5] On top of this, intense exercise can raise your internal body temperature, which can cause serious problems if you already have a fever.

Tips to boost your immune system to get you back in the game faster

If you do find yourself sick this winter, there are some immune-boosting tricks you can use to get back on your feet faster:

1. Get at least 7-8 hours of quality sleep

Not sleeping well is associated with a suppressed immune system and an increased risk of catching a cold. [6] Getting enough sleep will allow your body to recover and give your immune system a chance to win the battle.

» Using coffee to stay awake? Discover how caffeine affects your workout

2. Don’t forget to hydrate

Especially if you are still participating in light exercise, your immune system needs fuel—including fluids—so it’s important to rehydrate and replenish the electrolytes you lose through sweat.

3. Supplement with immune-boosting vitamins and minerals

Adding vitamin D, magnesium, and possibly a garlic supplement can boost your body’s response to infection, increase the production of your immune cells, and fend off unwanted inflammation. [7, 8, 9]

Smart rest: Maximize training benefits during illness

When trying not to let your sickness slow your training, remember: you know your body best. If you think you need rest, then rest! In the grand scheme, a few days off will have very little impact on your training. On the flip side, trying to push through a bad cold will only prolong the time it takes to get healthy again. It's better to rest up and come back stronger!

a green background with the words 'connecting to InsideTracker'.

Want to be proactive about your immune health? The InsideTracker Immunity Plan measures 10 key biomarkers that support and play a role in the body's natural defenses (including glucose, hemoglobin A1c, cortisol, and vitamin D).

Two screens showing the different stages of a vitamin drink

If these biomarkers are unoptimized, InsideTracker will provide food, supplements, and lifestyle recommendations to help you optimize them and strengthen your immunity. For example, if you're low in vitamin D, you may see a recommendation to increase your eggs, fish, or mushrooms intake. This plan allows you to select the Immunity goal as well as goals like Stress, Sleep, Energy, and Strength & power.


 [1] Jamurtas AZ, Fatouros IG, Deli CK et al. (2018) The Effects of Acute Low-Volume HIIT and Aerobic Exercise on Leukocyte Count and Redox StatusJ Sports Sci Med.17(3):501-508.

[2] Martin SA,  Pence BD and Woods JA. (2009) Exercise and Respiratory Tract Viral InfectionsExerc Sport Sci Rev. 37(4): 157–164.

[3] Lee HK, Hwang IH, Kim SY, and Pyo SY. (2014) The Effect of Exercise on Prevention of the Common Cold: A Meta-Analysis of Randomized Controlled Trial Studies. Korean J Fam Med. 35(3): 119–126.

[4] Gleeson M and Williams C. (2013) Intense exercise training and immune functionNestle Nutr Inst Workshop Ser. 76:39-50.

[5] Natalie A. Dick NA and Diehl JJ. (2014) Febrile Illness in the AthleteSports Health. 6(3): 225–231.

[6] Prather AA et al. (2015) Behaviorally Assessed Sleep and Susceptibility to the Common ColdSleep. 38(9): 1353-9.

[7] Martineau AR et al. (2017) Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant dataBmj. 356: I6583.

[8] Laires MJ and Monteiro C. (2008). Exercise, magnesium and immune functionMagnesium research21(2): 92-96.

[9] Josling P. (2001) Preventing the common cold with a garlic supplement: a double-blind, placebo-controlled surveyAdv Ther. 18(4): 189-93.