There's nothing like an intense, sweaty workout to make you feel like a million bucks—calmer, happier, and more comfortable in your skin (and your jeans). But anytime you push yourself physically, especially if it's a tougher-than-normal class or you're getting back into a routine after a hiatus, you may experience a few mild symptoms, especially if you're not properly hydrated. When should you be concerned?
"I tell my clients that the one symptom they should seek immediate attention for is any kind of chest pain or tension in the chest, arm, neck, or even back that persists for more than 20 minutes—it could indicate a heart attack," cautions Tommy Boone, PhD, MPH, board member of the American Society of Exercise Physiologists and Editor in Chief of The Journal of Exercise Physiology. Otherwise, here are a five exercise side effects that are okay to experience from time to time, and when to seek medical help.