It’s unrealistic to think you’ll never skip a workout. In fact, there are times when forgoing exercise is downright healthy, says Marty Lillystone, an exercise physiologist at Beaumont Hospital Weight Control Center in Royal Oak, Mich. Here are five occasions when you can give yourself a pass – for a day or two.

You’re in pain. Being a little sore from a workout or arthritis is normal. But if you’re so uncomfortable you can’t perform daily activities, easily (such as getting in and out of your car), take a day or two off. “If you’re still in pain after the break, see a doctor,” advises Lillystone. You should seek professional help anytime you experience extreme or sharp pain in any part of your body, either during exercise or after; tightness (like a crushing feeling) in your chest, abdomen or back; or tingling in your arms, leg, chest or face.

You’re worn out, either mentally or physically. “When your gut tells you to sit it out, listen,” says Lillystone. Specifically? If you’ve been doing the same activity for two weeks and can’t bear the thought of doing it one more day, cut yourself some slack or find another activity to try.” Ditto for really strenuous workouts – if you’re exhausted after your last sweat session, rest for a day before picking up again.

You worked out with weights yesterday. When strength training, it’s best to wait at least 48 hours before working the same muscle group again; this gives your muscle fibers a chance to repair. (You can continue doing cardiovascular and flexibility exercises in between weight workouts without hindering recovery.)

You have a chest cold or the flu. A rule of thumb doctors and exercise professionals use: If you have congestion above the neck (like a stuffy nose), you still can work out – but if it’s in your chest, or you have a fever or more than 99.5 degrees, stay home. Exercise may make your condition worse.

The weather is unbearably hot or cold. If you’re exercising outdoors and temperatures are dangerously high or low, take the day off, advises Lillystone. Or do a modified workout indoors – stretch or walk in place for a few minutes.