Another flu season has arrived and there are few things more frustrating than missing training due to illness. That’s why many of us often train despite feeling under the weather.
While it is important to take it easy when our bodies are fighting an infection, there are instances when we could keep exercising.
Above the neck
This decision often boils down to the ‘neck test’. This commonly used indicator stipulates that if you experience symptoms above the neck associated with an upper respiratory tract infection (URTI), such as a runny nose, nasal congestion, sneezing, or a minor sore throat, you should be okay to exercise.
If you choose to train, keep the intensity, duration and volume below your normal levels. It’s also important to listen to your body and make rational choices based on how you feel before, during and after training.
Physical activity can sometimes help to alleviate minor symptoms like nasal congestion and lethargy when you are suffering from a mild URTI.
This happens as your respiratory tract and blood vessels dilate, which delivers more oxygen and nutrients throughout the body for energy.
Getting out for a gentle pedal or run can also make you feel better due to the endorphins the activity releases.
Stop exercising immediately if you experience:
- Chest tightness or pressure
- Trouble breathing or excessive shortness of breath
- Light-headedness or dizziness
- Difficulty with balance
Don’t make matters worse
Of course, training with a head cold could compromise your immune system or cause the infection to spread to your lungs.
That’s why it is often best to rest and seek treatment early on in the infection, otherwise, you could prolong your time off from training.
A beneficial metric to monitor to pre-empt an infection is your resting heart rate. Measuring your heart rate (manually or with a wearable device) when you wake up each morning can provide an early indication of an infection. Any reading that is 7-10 beats per minute higher than your normal resting heart rate could suggest that it is better to rest rather than train.
Below the neck
However, if you have a tight chest, experience coughing or have a fever (your body temperature is 38.3°C or above), you should avoid all exercise until your symptoms pass.
Other ‘below the neck’ symptoms to look out for include chest congestion, chills, an upset stomach, muscle or joint pain, or general fatigue. These symptoms generally indicate that you’re infected with a cold or flu virus.
Studies conducted on animals that were infected with a systemic virus found that engaging in physical activity while experiencing fever and pain exacerbated and prolonged symptoms.
An infection can also become life-threatening in some cases because certain virus strains can cause myocarditis (inflammation of the heart wall), which can damage heart tissue.
As such, the worst thing you can do when battling a severe illness or cold or flu virus is trying to sweat it out with exercise.
Do not exercise if your symptoms include:
- Chest congestion
- Coughing and/or wheezing
- Muscle aches
- Joint pain
- General fatigue
Medication and your body
And training while taking medication to treat a secondary bacterial infection caused by a cold or the flu might cause additional complications.
Research studies link certain antibiotic use with soft tissue injuries, specifically in tendons. Other potential issues may include gastrointestinal distress, including nausea and diarrhoea, decreased athletic performance due to fatigue (remember, your body is still fighting off an infection), and photosensitivity, which can increase your risk of sunburn.
For these reasons, and to allow your body time to recover, doctors generally recommend that you stop exercising until your course of antibiotics is over.