Can I Exercise if I am Sick?

This is a question I get all the time, especially in the pharmacy! Now that the weather is getting cooler, head colds and other viruses become more frequent. It is important to know when it’s ok to exercise and when you should rest in order to speed your recovery.

We know that exercise improves our overall fitness, which can help boost our immune system and defend our bodies against infections. Performing a structured workout routine where you’re breathing heavily, sweating, working hard, and feeling some discomfort triggers a stress response in the body. A normal, healthy body can easily adapt to this stress and over time, this progressive adaptation is exactly what improves our fitness and strength. However, when our health is compromised due to sickness, the stress of a tough workout can be too much for our immune systems. Strenuous or high intensity workouts can reduce the number of infection-fighting white blood cells in our bodies. At the same time, our stress hormone cortisol increases, which may interfere with the ability of certain immune cells to work efficiently, affecting our recovery.

Activities to consider when you are sick include: walking, light jogging, swimming, cycling and yoga. These should be done at a low intensity, and have actually been proven to improve recovery. I highly recommend avoiding strenuous activities such as heavy strength training, endurance training, high intensity interval training, sprinting or other power activities and exercise in extreme temperatures as the stress that these place on the immune system can impact recovery and potentially cause your illness to worsen.

Another thing to consider is the health of others around you if you are training in a gym or group fitness. A cold is caused by a virus which can be easily spread by contact with surfaces infected with germs and then touching your eyes, mouth or nose or by breathing the air near people that are sick and close personal contact. For everyone’s sake it can be better if you stay home! If you have a cold, you should follow these tips to prevent spreading it to other people:

  • Avoid close contact with others, such as holding or shaking hands, hugging and kissing
  • Move away from others if you need to cough or sneeze
  • Cough and sneeze into a tissue, completely covering your mouth and nose and then throw it away
  • Wash your hands immediately after coughing, sneezing, or blowing your nose
  • Disinfect any surfaces and equipment you have touched.


The best way to determine whether you should work out or not is to let your symptoms be your guide. I recommend performing a ‘neck check’. If your symptoms are only above the neck, such as a sore throat, nasal congestion, sneezing, and watering eyes, then it is generally fine to exercise. If your symptoms extend below the neck, such as coughing, body aches, fever, fatigue, vomiting or diarrhoea then it is best to avoid exercise and focus on rest and recovery. It is important to consider all of the stresses you are dealing with in your life at the moment – not just physical – emotional, psychological, environmental stresses all play a role in the rate at which you recover.

If you do decide to exercise with a cold and you experience any of the following symptoms, then you should stop your activity immediately and seek emergency medical help:

  • Chest tightness or pressure
  • Trouble breathing or shortness of breath
  • Light-headedness or dizziness
  • Balance problems

If you have any further questions about exercising while unwell, feel free to contact me!