It’s not necessarily bad to work out when you’re sick, but it can be in some circumstances. It depends on what’s causing your sickness. The general rule for exercising is different for the common cold and allergies than it is for the flu, fever and nausea, for example. It also depends on how you feel. You might not have the energy for even a moderate workout, in which case you may want to skip exercise altogether.
Cold, Allergies and Head Symptoms
You can do a moderate workout if you’re ailing from the common cold, allergies or have other symptoms that affect your head, as long as the symptoms don’t include a fever. If you feel up to exercise, it’s not bad to work out if you have a stuffy nose, watery eyes or other cold or allergy-induced symptoms. Although working out won’t make your cold or allergies disappear any quicker, it won’t make them worse or prolong your sickness. Stick to moderate activity, such as walking, and reduce your weight training load by 25 percent to give your body a break during its illness.
If you’re sick from symptoms that resemble the flu or otherwise hit below your neck, you’re better off skipping your workout. Your immune system is already weak, so your body needs all your energy to recover. Working out could slow that process. Symptoms that require rest include aching muscles, fever, fatigue, swollen glands and nausea. Particularly avoid strength training if you have the flu, because your body is using all its energy to fight off the virus. Lifting weights can make your immune system less efficient and even make you sicker than you already are.
The common cold is highly contagious, a consideration if you decide to take yours to the gym. A cold virus, which infects your body after entering your nose or mouth, can spread when you sneeze, cough or even talk. It also spreads germs by hand when you touch someone or something -- like a weight bench or machine. The germs linger and infect others if they touch their eyes, mouth or nose after touching the germy machine. Warn people that you have a cold, and refrain from sneezing and coughing on fellow gym members.
Your overall fitness level is not going to nosedive just because you miss a few days, or even weeks, of working out. As long as you were consistent in your workouts, missing sessions to recover from sickness won’t make too much of a difference. When you are well enough to resume your workouts, do so slowly and gently to get back into the routine. Keep your first week of exercise at a moderate level when you resume, and slowly increase to your usual intensity over the next week or two. Never work out if you have a fever, as doing so can result in heatstroke and kidney failure, especially if your fever is higher than 100 degrees Fahrenheit.