My rules of thumb: if the cold is in your chest, don’t run. But help body circulation with light stretching/yoga.

If it’s ‘just’ in your head/nose, it’s ok to do easy distance – nothing that will drive it into your lungs. And blowing your nose onto the side of the road saves tissues. Just be sure no one is running behind you.

Start keeping a log of your morning heartrate. Establish a baseline. When it rises 5 or more beats for a few days in a row, you’re probably fighting something/a cold is coming on. After an illness, you can start training when your heartrate is back to normal. However, long your illness (example: 5 days), start training at the point you were (double the illness time) 10 days ago. Don’t try to make up lost training hours or workouts.

That’s my two cents.

Blanket rule: rest from aerobic or strenuous strength training. Especially if you have a sore throat, fever, chest congestion, or nausea.

I know it’s frustrating to miss training, but look at it this way: healthily executing our planned training and recovery is going forward; training when ill or under-recovered is going backwards; resting when ill or under-recovered is staying in the same place (roughly, as long as this doesn’t go on for weeks.) No, it’s not as good as training healthy, but you can’t change the fact that you’re sick or tired so you might as well make the most of it. And encourage speedy healing.

Some athletes who know their bodies very well may be able to decide it’s okay to train lightly through a cold. Or if you are very familiar with your heart rate data you may also be able to make this call. To get into the weeds briefly, if you measure your resting heart rate or your heart rate variability, and both are relatively unimpacted by a minor cold, it’s probably okay to train lightly (no intervals, no races) throughout.

Restorative exercises may have their place throughout illness, and the increased circulation may even speed your recovery. If you follow a prehab or injury prevention routine, for example, which includes easy mobility exercises, you can continue these as long as they don’t exacerbate symptoms. Same for yoga, stretching, foam rolling, etc. Take this time while you’re sick to take care of the little details that might get overlooked when you’re busy training. During extreme weather conditions, doing these easy exercises indoors can help protect your body from the additional strain of heat/cold/air quality, etc.

So how do you know when to get back into training? This one follows a pretty basic rule. Once you start to feel like you’re on the upswing, and symptoms have diminished to the point where exercise sounds good (and/or you have heart rate data that indicates things are getting back to normal), go for an EASY jog. If that makes you feel better (energized, clears your head, etc.) then keep building slowly from there as you approach full health. If it makes you feel worse, take another couple days off.

Regarding coming back to training and “making up” for missed workouts: generally, don’t try to make up workouts you missed. Don’t ever try to make up the missed miles (i.e; if you missed 20 miles and next week is scheduled to be 30 miles, don’t run 50!) If you are preparing for a specific event, depending on your training schedule, a coach might change your upcoming workouts to accommodate one specific workout you missed, but if you’re calling your own shots just keep going with whatever plan you are on. If you are in an aggressive mileage or volume-building plan, in preparation for a marathon for example, consider whether you are ready to jump to the next week’s mileage. You might be, or you might want to redistribute your mileage increase over the next few weeks to effectively pick up where you left off when you got sick. A good training plan will be long term-enough that you have time to readjust if training gets temporarily derailed by something like a cold.

Of course it goes without saying that if you’re sick enough to need a doctor’s input, anything an endurance coach has to say goes out the window. Take care of yourself, first and foremost!