It’s the time of year when every other person I meet seems to be coughing or sneezing and having a sensible strategy up your sleeve when the inevitable happens could save you a lot of problems.
Many doctor’s advise the ‘neck check’. Anything below the neck including a sore throat, cough, aches and pains, elevated pulse then you shouldn’t train. If you just have a runny nose or sneezing with no other symptoms, then light exercise should be OK though you should not train long/hard or race because that will supress your immune system further and leave you wide open to more serious illness.
Once your symptoms have passed then make sure to spend a few days gradually increasing your training load before attempting anything hard.
I’ve found with years of experience that a few days off beats trying to muddle though and getting properly sick, which can mess up your training for weeks. Re-frame those few days off as an opportunity to let your body super-compensate from previous training.