When you're feeling sick, exercise comes last on your list. Yet, you don’t want to ruin months of hard work and lie in bed all day. So, what should you do? Is it safe to work out when you're sick? Or is it better to get some rest?

Squeezing some exercise into your schedule isn't necessarily a bad idea. It can actually boost your immune function and speed up recovery. However, you won't be able to perform at your peak. Thus, it's important to adjust your workouts accordingly.

Exercise or Rest While Sick?
A simple cold or flu can ruin your best intentions to keep fit. Hitting the gym seems the worst thing you can do. Health experts disagree. Unless you have a fever or a really bad flu, exercise can help.

The cold season creates a perfect environment for common cold and flu. Throat and ear infections, tonsillitis, sinusitis, and coughs are common in the winter months.

Seasonal flu spreads easily from one person to the next, and can cause mild to severe symptoms. You may experience muscle and joint pain, chills, fever, runny nose, dry cough, migraines, and low energy. Even though these issues go away within a week or so, their impact can be devastating.

Exercise may seem counterproductive when you're sick. Yet, it can actually help you recover faster. Moderate intensity cardio, for instance, improves immunity. Strength training helps your immune system produce antibodies that fight microbes. Being sedentary, on the other hand, can weaken immune function.

Physical activity can help you in more than one way. First of all, it relieves stress and increases endorphin production in the brain. Even if you're sick, you'll feel better - at least mentally - after hitting the gym.

Secondly, exercise boosts your energy and stamina. This is particularly beneficial when you're feeling sick. Lying in bed can make things worse.

Working out will also lift your mood, improve the innate and adaptive immune response, and strengthen your natural defenses. The key is to listen to your body and refrain from going overboard. The stress of a challenging workout can be more than your body can handle in times of sickness.

Do's and Don'ts of Working Out When You're Sick
Before starting your workout, keep some things in mind. First of all, do not exercise if your symptoms are below the neck. For instance, if you're dealing with body aches, severe cough, chest congestion, or vomiting, get some rest. Working out can worsen your symptoms.

Feel free to exercise if your symptoms are above the neck. A runny nose, sore throat, or sneezing shouldn't stop you from hitting the gym. However, if you're feeling really sick, take a break for a day or two. As your condition improves, resume your workouts gradually.

Ideally, opt for strength training and low or moderate intensity cardio. Weight training stimulates innate immunity, while moderate cardio boosts adaptive immunity response. Sweating from exercise accelerates recovery by killing germs.

In a 10-day study conducted on subjects with rhinovirus-caused upper respiratory illness, those who worked out for 40 minutes every other day reported significant improvements in their symptoms compared to those who didn’t exercise. They have recovered faster and experienced less discomfort.

As a rule of thumb, avoid HIIT and other intense or prolonged workouts. According to science, these activities suppress the immune system, making your symptoms worse. Moderate intensity exercise has the opposite effect. It's particularly effective for those with respiratory viral infections.
Considering these facts, it's no doubt that exercise is safe when you're sick. As long as you don’t overdo it, you can stick to your workouts.

Summary

• Strength training and moderate intensity exercise are safe when you're sick. 
• Don't work out if your symptoms are below the neck. 
• Keep the intensity low or moderate, and avoid challenging activities. 
• Working out when you're sick can boost your immune system and speed up recovery.