As sickness can be a broad term for a multitude of symptoms that are causing someone to feel less than their best, it is difficult to determine when you should actually exercise and when you should rest if feeling unwell.
A general guideline is to let your symptoms decide for you and if you are feeling worse after any physical exercise then it may be an indication to rest.
A lower level intensity and shorter duration of exercise can still be carried out if symptoms are 'above the neck' and include;
Runny nose/nasal congestion
A scratchy or mild sore throat
Activities such as jogging, yoga, walking and biking can be carried out at a lower intensity and could be done at home or away from the gym in order to contain the spread of any illness-causing germs.
Studies have shown that mild exercise during a common cold does not affect the duration or the intensity of the symptoms experienced and can actually ease some symptoms such as nasal congestion by opening up the nasal passages.
Exercise is NOT recommended if symptoms are ‘below the neck’ and include;
Widespread Sore muscles/Deep Aches
Gastrointestinal Disturbances/Stomach Upsets
Resuming any exercise routine, especially one of high intensity, after illness should be gradual as the body takes time to recover completely.
This is a general guideline so if you feel miserable from any symptoms a small break may be beneficial and if there are any concerns then consult a general practitioner on whether it is safe for exercise.