To complete a marathon you need to train. Finding the time and the commitment to train is often the biggest challenge. You need to gradually increase mileage to get to this distance and to stay healthy. We see lots of injury when the distance is pushed too fast. Both walkers and runners get injured, the injuries are different.
Walkers have more problems with their feet while runners have more knee problems.
The 12 pace groups of the Marathon Clinic provide support for runners of all paces from those racing a sub 3 hour marathon to those wishing to complete a marathon in 5 hours. I'm certain the conversation is different in groups with more males. Sometimes men learn more about female health problems and anatomy than they ever wanted to know. Women can ask advice or simply vent their frustrations while in a group situation. I hear conversations about work, relationships, children, travel, sports and the ever popular food as the distances get longer.