5 Signs Your Workout Is Bad For You

Feel the burn. No pain, no gain. Hurts so good. With fitness motivations like these, it's no wonder that many people think that gritting their teeth through workouts is to be expected.

"It's true that feeling a little sore after exercise is a good thing," says Jessica Matthews, an assistant professor of exercise science at Miramar College in San Diego and senior advisor of health and fitness education at the American Council on Exercise. "It means your muscles are getting stronger."

But Matthews warns that certain types of pain can signal a problem, such as an overuse injury. The key is telling the difference. To determine if your workout is doing your body more harm than good, pay attention to the following red flags.

1. Your muscles shake like crazy. 

"Some quaking isn't cause for concern," says Matthews. But if your arms start vibrating at a 7.0 on the Richter scale or start to give out, that's a sign of muscle failure. Not only do you run the risk of dropping a weight on your foot or falling, but you're setting the stage for damage. "When you're too fatigued, you won't be able to maintain proper form during an exercise," says Matthews. "That can lead to a muscle strain or tear."

2. You experience a sudden, sharp, or radiating pain. 

You can expect a general, growing ache in your muscles—that's a sign your workout is challenging. But an intense pain that appears quickly indicates that something's wrong. "Don't try to push through the movement," says Moira McCarthy, MD, an orthopedic surgeon specializing in sports medicine at the Hospital for Special Surgery in New York City. "That can lead to a muscle or joint injury."

3. After that jog, your foot or knee looks a little swollen.

Redness, swelling, or persistent pain suggests an overuse issue, such as runner's knee or a shin splint. (Prevent shin splints with these 4 simple tips.) "Take it easy for a few days," says McCarthy. You may need to spend more time warming up and stretching before pounding the pavement. But if it continues to hurt with each run, you may need to see a physical therapist. She can help you correct your form and strengthen any areas that may leave you susceptible to injuries.

4. That workout was 3 days ago—and you're still sore. 

You went hard in the weight room, and it still hurts to climb the stairs. Some stiffness is expected: Delayed onset muscle soreness (DOMS) is caused by tiny tears in the tissue, and when your body repairs those tears, it rebuilds your muscles stronger. But DOMS should resolve within 24 to 48 hours. If it doesn't, says Matthews, "it means that you pushed yourself too far, too soon." Wait until your muscles heal and the pain disappears before heading to the gym again. "If you try to exercise with a limited range of motion, you may wind up favoring one side or compromising the movement," says Matthews. "Over time, that can lead to an acute injury."

5. Your shoulder, knee, or hip gripes during a lift or press.

Having pain with one certain type of movement is a sign that something's wrong, says McCarthy. If the pain is sharp, have an orthopedic specialist check it out. If the pain isn't too bad, she recommends you take time to better prepare for your workouts. "Make sure that you're warming up and stretching properly, and hydrating during exercise," she says. You may need to bring exercise back to the basics. "Don't try to keep up with others," says McCarthy. Try lighter weights, slow your movements, and pay close attention to your form.