Headaches after or during a session of pushups are so common, it may surprise you. That's the bad news. The good news is that any problem as common as that generally has a solution. In the case of pushup-induced headaches, the best solution depends on what's causing the problem.
Forgetting to Breathe
Lack of oxygen can cause headaches. If you hold your breath or forget to breathe while doing pushups, you can suffer from a lack of oxygen. When you're only doing 10 to 20, it's usually not a problem. By the time you're up to 50, it's a headache waiting to happen. Hyperventilating during your pushup session can have the same results. If your headache is buzzing rather than sharp or throbbing, and if it seems general rather than in a specific area, improper breathing is a likely culprit. Mild dizziness and shortness of breath is another sign that improper breathing while performing pushups is the cause of your headache. To fix this, focus on your breathing throughout your set. It helps to time your breathing with your pushups -- breathe in on the way up, out on the way down.
Hanging Your Head Down
Tightened or injured muscles in your neck can cause tension that results in a headache. You can identify these by headaches localized in the lower back of the head, or with pain that shoots in a line down your neck. These are caused by poor form that puts too much stress on your neck. To fix this, focus on keeping your neck straight and aligned with your spine throughout your sets. Keep your eyes focused on a point midway between your hands, rather than looking forward or letting your head hang.
Clenching Your Jaw
Many athletes clench their jaws as the repetitions get harder. This is normal, even unavoidable. If you clench too hard, it can cause muscle tension and pain in your jaw, orbital sockets and temples. If you experience this kind of pain, try breathing through an open mouth as you do your repetitions. This keeps your jaw slack. Another option is to wear a mouthpiece -- it won't stop you from clenching, but it will reduce the tension in the muscles of your face and neck.
Although often a sign of something minor, headaches could also be a sign of a serious problem. If you experience severe pain, dizziness or lightheadedness, you should consult with a doctor. If your symptoms are debilitating, or accompanied by numbness and pain -- especially to the left arm or chest -- get medical help immediately. In a worst-case scenario, this can save your life. In a false alarm, it can get you valuable doctor's advice about what's causing the headaches.