How to remain calm before a marathon?

Whether you remain calm or not, will depend on you and each individual reacts differently to a situation like that. Of course every one will experience some level of nervousness before the start of a race and you must be mentally prepared to stay calm. Breathing always helps and you take long deep breaths and exhale through your mouth. This is a form of yoga that will increase blood circulation and create a sense of calmness before the marathon. Many athletes use this technique to stay focused and calm. You can also reduce the stress by doing some basic exercises and stretches. This might help to an extent.