I was prompted to share this information for 2 reasons: 1) the cold and flu season is around the corner 2) I was sick recently and tried to get back into exercise too early. I ended up feeling horrendous the following day and it set my recovery back significantly. This even happened when I thought I was starting to feel better. If you work out too soon, you take away your immune system helper cells that are trying to heal you by getting them to repair your muscles. This makes you sicker as your body needs all of those immune system cells to get you better!
It applies as well if you injure yourself, eg damage your meniscus or cruciate in your knee. It is tempting to still train and work on your upper body but, it stresses your whole body which takes away from healing your knee. This article gives some great insight into what happens during this time.
Use your extra time to focus on eating nourishing foods to help you heal. Try bulk meal prepping ahead of time so you have nutritious food that is ready to eat in your fridge or freezer.
So, if you are unsure whether to exercise or not, it is usually best to rest or just go for a walk or light bike ride and consider the following:
- Consistent, moderate exercise and resistance training can strengthen the immune system over time. So, go for it and train hard whilst you’re well.
- But single high intensity or long duration exercise sessions can interfere with immune function. So, ease off when you are unwell.
Interestingly, people who never exercise get sick regularly, those who exercise between once/month and 3/week had the most immune strengthening effect and people who exercised more than 4 times per week got sick the most.(a)