I received an excellent question via email this week about working out when you are sick. As always with complicated questions, the answer is: it depends. I know that’s not too useful, so I’ll go into it a little more deeply.
The first thing to consider is what type of illness you have. My rule of thumb is to consider how much of your body the illness is affecting. If it’s a simple head cold, you’ll be able to do more than if it was in your head and chest. If you’re fighting something more systemic, like the flu, you won’t be able to do nearly as much or anything at all.
Assuming I am dealing with something fairly local, I typically start a light warmup to see how I’m really feeling. Often, after 10 minutes of moving around lightly, I start feeling better and better and can actually get a productive session in that feels pretty good. The rest of the time I still feel awful. Those days, I never push it. If nothing is going right after the warmup, you probably need the rest.
I do tend to keep workouts light even if I do feel pretty good when I’m sick. The body is still fighting something off and it doesn’t need you burning through all its resources on one of the hundreds of training sessions you’ll have this year. Keep everything at a conversational pace and take plenty of rest between sets. You aren’t aiming for gains here. You’re keeping the body moving and avoiding major losses.
There are two more things I’d like you to consider on this topic. First, ask yourself if extra rest will be helpful or harmful to your training overall. It’s been my experience that the people that want to train while they are sick are usually the most committed and haven’t missed a workout in a year. The time off, won’t hurt that individual. In fact, after they get back to 100%, they might find they start hitting personal bests because they’ve had some much needed time off.
The last thing I want you to think about is how you will affect the people around you. If you’re sick and going to workout, make sure you don’t put anyone else at risk of catching whatever you’ve got. Do your workout at home, in private or someplace where people rarely are. Nobody wants the guy that’s obviously sick setting up next to them at the gym. Be sure to keep everyone around you safe.
This entire process will be very individual to you and will likely change depending on your illness. Sometimes I’ll get sick and I can work right through it. Other times, something that seems simple and easy will keep me from training for a week. In the end, I never worry about it either way. We all have years to catch up!