To understand why fitness is so important, it helps to understand how it helps you. What exactly is going on in your body when you work up a sweat?

Every time you work out, exercise sets in motion a cascade of events in your body that collaborate to help you lose weight and get healthier. When you exercise—whether it’s walking, biking, or lifting weights—your muscles contract. To contract, muscles need oxygen. “The benefit of exercise is it stimulates the body to deliver more oxygen to the muscles that are contracting,” explains Robert Robergs, PhD, FASEP, professor of exercise physiology at the University of New Mexico, Albuquerque.

The need for extra oxygen makes you breathe faster. Every time you inhale, a rush of oxygen-rich air flows into your lungs. Oxygen makes its way into red blood cells, where a molecule called hemoglobin transports it to the muscles—and everywhere else in your body it needs to go. Your heart must pump harder to send all that oxygen-rich blood to your muscles. The more the heart works, the more efficient it gets at its job. “Over several weeks the heart becomes a better pump,” Robergs says. Meanwhile, your body produces new blood vessels to help carry all the extra blood the heart is pumping. Those extra vessels take some of the work off your existing blood vessels, thus reducing your blood pressure.

That’s not all exercise does for you.

“Because exercise burns calories, it can help reduce body fat. It can raise the good cholesterol—the HDL cholesterol,” Robergs says. HDL—or high-density lipoprotein—cholesterol is the “healthy” form that helps sweep the low-density “bad” cholesterol to the liver for removal, before it can build up in the arteries and lead to coronary artery disease.

It’s hard to argue with the long list of the benefits of exercise.

“There’s evidence to show that exercise helps prevent and manage chronic illnesses like diabetes, obesity, and depression,” explains Rosalind Ramsey-Goldman, MD, DrPH, Solovy/Arthritis Research Society Professor of Medicine at the Northwestern University Feinberg School of Medicine in Chicago. This is important for people with lupus because these conditions can be side effects of corticosteroid use.

How exercise specifically benefits people with lupus

Working out when you have lupus might seem like an insurmountable obstacle, but it’s worth the effort. “Taking care of your body doesn’t come second. It’s the first thing you should be concerned about,” says Cassandra Corum, a California-based wellness expert and strength and fitness coach. Corum, who has a connective-tissue disorder, knows what it’s like to live with a chronic illness.

“When there’s something you have that you can’t control, it’s extremely frustrating. It can make you feel like your life is over,” she says. Exercise gives Corum the chance to work out some of those frustrations. “I feel like I can control my body, rather than my body controlling me.”

If exercise is a dirty word to you, just think of it as "movement"

Exercise can only help you if you do it. Ideally, you need at least 30 minutes of exercise a day, five days a week, to get the maximum health benefits, but that goal can be entirely unrealistic for many people with lupus. How can you even think about walking outside for 30 minutes when you can barely drag yourself out of bed and walk to the kitchen?

People with lupus need to change their perception of the word “exercise,” says Ramsey-Goldman. “Exercise can mean moving, which is OK. It doesn’t have to only mean that you have to work out hard at the gym.”

It doesn’t matter how or where you fit in this movement, just that you do it.

You will want to combine some type of cardiovascular exercise to get your heart pumping, weight training to strengthen your muscles, and stretching to improve your flexibility and range of motion—but all at a level that suits your abilities and is workable for you. Again, it’s important you speak with your physician about beginning a new workout routine.

“You can’t go from 0 to 100 overnight,” Ramsey-Goldman says. “Don’t try to do too much too quickly, because then you’ll hurt yourself and you won’t want to do any more.” If you can only exercise for five minutes at a time to start, or you can only do gentle slow stretches, that’s fine. Gradually build up the length and intensity of your routine when you feel ready.

While you’re redefining what it means to exercise, you also need to redefine your attitude about fitness. “If you don’t think you can exercise, that’s going to be a barrier to being able to do it,” Ramsey-Goldman says. “Cast off the mindset of, ‘I’m sick; I can’t do anything.’ When you move, you actually feel better.”

Best ways to exercise with lupus

• Go for a swim at your local pool or health club. Not only will the buoyancy of the water cushion your inflamed joints, but it will also keep you cool and comfortable while you exercise. Walking, bicycling, yoga, and Pilates are other good low-impact options.
• Avoid exercises that can aggravate your joints, like running or high-impact aerobics.
• Begin very slowly. If all you can do is lift your arms or legs at first, do that for a couple of minutes at a time. Then add light weights. Gradually increase the length and intensity of your workout and add in new exercises when you’re ready.
• Vary your routine so you don’t get bored, and change up your exercises so you’re always working different muscle groups.
• Wear sturdy sneakers or shoes when you work out, so you don’t fall.
• Never work out to the point of pain or exhaustion. You could injure yourself or make your condition worse.