Run marathon regularly, whether it is harmful to the body?
It depends on the individual. Some (few) people can do it regularly. Others, who are capable of that distance, train for months and don't do it more than once or twice a year, if that. As with any physical exercise, it can be harmful to the body if the person isn't fit enough, trained properly, and fueling properly. Running long runs regularly does increase risk of various repetitive motion injuries which includes strains on the joints and bone fractures. What you mean by "regularly" is also important. Is that running a marathon distance (all at one time) weekly or monthly or less than that? What's regular to you, may be irregular to someone else.
Some bodies are built for endurance, others are not. To me, "regular" means daily. There's no reason to run 26.2 miles daily even if you can. Take care of your body, you only get one!
A couple of years ago, some researchers reported it is OK to run a few marathons. But, those who ran regular marathons had scar tissue in their heart muscles.
all exercise puts wear on the joints, todays's marathon sports medicine has done a lot to decrese exercise-injuries. find a healthy schedule to train with, and maybe do cross-training so as exercise the entire body and not just one area of muscles and joints. i thing it tis the long term health benefits of exercise to the heart and lungs, the cardio-vascular pulmonary systems, which are healthiest; that is if you follow protocol and do not strain the heart muscle with over exertion. a training rate is 75% of the maximum heart rate minus one's age.
It can be bad for your knees- over time,
Nausea vomiting, tired teeth, uncomfortable facial muscles, chronic joint sports injuries
Heartbeat speeding, sweating, gasping, muscle aches, body fatigue