The favorite motto of the athlete is that pain is just weakness leaving the body. However, blindly following this advice can lead you to permanent injury, so it’s important for every fitness buff to learn which pains you should never ignore in order to remain safe and fit.

1. You should never ignore a severe headache that occurs during a workout, especially if its strength training. Strenuous lifting can often cause blood vessels in your head to bulge and damage venal and arterial walls. A severe headache in the middle of lifting is grounds for stopping your workout and going to see a doctor to prevent the bursting of blood vessels in your skull.

2. Severe abdominal or groin pain during a workout can point to a hernia. If you experience a sudden sharp pain in your lower abdomen or groin during a workout you should stop the workout and see if it goes away on its own. If it does, it was likely only a muscle strain. Otherwise, you’ll probably need to go see a doctor,

3. Sudden back pain is the most dangerous pain to experience during a workout. It’s common for people who are lifting to accidentally shift their position while having extra weight applied to their vertebrae, which can result in slipped discs. The back pain caused by this can be incredibly persistent, so it’s important to keep good form while lifting and to stop and see a professional if you have sharp back pain while exercising,

4. Shin splints is a common form of injury for runners; if you begin experiencing sharp pains in the shin area while running or walking, you have likely developed micro-fractures in your shin bones. These micro-fractures will only heal if you avoid putting any weight on your feet for a period of time determined by how serious they are. Therefore, if you have shin pain that doesn’t go away it’s important to go to a doctor and discuss being fitted for crutches or some other option that will allow you to keep weight off the affected area.

5. Runners should be wary of their ankles; most ankle sprains come from sudden twisting motion, but it’s always possible to get them from running over time and having the connective tissue involved become more and more inflamed, which feeds into itself and exacerbates the problem. If you feel your ankle becoming very sore after a run, you may want to forgo running for a few days and let it recover to avoid spraining your ankle from overuse.