If you've ever spent the day after an intense workout soothing your sore legs with a foam roller, you know your muscles can give you plenty of feedback about how you're feeling. Usually the message is pretty straightforward—if your glutes are sore after doing a million squats, that's a no-brainer—but what do those weird muscle cramps, shakes, and serious aches mean? Here are a few things you can learn from your muscles. (Looking for more ways to live a happy, healthy life? Order Prevention magazine—and get a FREE Yoga DVD when you subscribe today.)

"You need a rest day."

When your muscles work harder than usual, it creates tiny micro-tears; that's why you feel so sore the day after a strenuous workout. As your body repairs those tears, you build muscle, which means recovery is a vital part of your fitness regimen. So if you're still aching after a day or two, listen to your muscles and go easy. "If you realize you may have pushed too hard, remain hydrated and do some light aerobic exercise such as walking or jogging," says Luga Podesta, MD, director of sports medicine at St. Charles Orthopedics in New York. (Here's how to start walking when you have 50 pounds or more to lose.)

"You pulled a muscle."

If you're in a world of hurt after a workout, (these 7 common workout mistakes are setting you up for a world of hip pain) you may wonder if you've actually injured something. To tell the difference between a sore muscle and a pulled muscle, pay attention to timing and symmetry. "A muscle strain often involves the sudden onset of pain during certain movements in one muscle, whereas post-workout soreness begins up to 72 hours after exercise," says Vijay Jotwani, MD, a primary care sports medicine physician at Houston Methodist. "Post-workout soreness will often occur on both sides of the body, whereas soreness from a pulled muscle will typically only occur on one side."

Most pulled muscles can be treated at home with RICE (rest, ice, compression, and elevation) and OTC anti-inflammatory meds. If that doesn't help or the pain is downright excruciating, see a doctor.

"You're not drinking enough water."

Cramps happen when a muscle contracts involuntarily. While researchers haven't pinpointed exactly what causes these spasms, dehydration seems to increase the risk, says Brian Schulz, MD, orthopedic surgeon and sports medicine specialist at Kerlan-Jobe Orthopaedic Clinic in Los Angeles. "Avoidingexercises in extreme heat and taking frequent breaks to rehydrate can prevent cramping or more serious injury."

"You need electrolytes."

After a particularly intense workout, it's not enough to just sip water—you also need to replenish minerals like sodium, potassium, and magnesium that help your body maintain proper fluid balance. "The depletion of these important salts and water result in restricted blood flow and lead to muscle injury, pain, and cramping," Podesta says. Not a fan of sugary sports drinks? Foods like bananas, salted peanut butter, seaweed, and milk can also help replace electrolytes. (You absolutely need these 13 power foods that lower blood pressure naturally.)

"You're under the weather."

If you're feeling achy for no apparent reason, your muscles may be warning you that you're getting sick—especially if you're also a bit nauseous or lethargic. "The inflammatory process the body uses to fight viruses is what causes muscle aches when you have the flu," Jotwani says. (Feel better ASAP: Here's exactly what to eat when you have a cold or flu.) Another possibility: A medication you're taking is making you feel lousy. Some prescription meds can cause inflammation, so if you've recently started a new drug and are feeling achy be sure to tell your doctor.

"You partied too hard."

After a few too many glasses of wine, your muscles may feel like you ran a marathon. Alcohol activates your body's immune system—the inflammatory effects start to kick in within minutes—plus it's a diuretic, which can make it harder to stay hydrated. "The combination of dehydration and inflammatory response both lead to muscle soreness," Schulz says. To help stave off the aches and pains of a hangover, sip a glass of water after each cocktail.

"You're pushing your limits."

Exercise should never be painful, but if your muscles shake a little during aworkout that's actually a good thing; it's sign that you're working hard enough to make progress and avoid hitting a plateau. As you get stronger and build stamina, Jotwani says, the shakiness will subside—at least until the next time you ramp up your workout.

This article originally appeared on Prevention.com.