The blended word is "telethon".
walkathon by JAYSON CARL L. GABALES
Yes, a person can walk in the Phoenix marathon. In addition to runners, people walk and even get pushed in wheelchairs.
Blended word
The blended word for lecture demonstration could be "lecturation."
The blended word of fan and magazine is "fanzine."
walk + marathon
Marathon is a place in Greece.
He was late for the marathon.
Yes. The Marathon is second at 42.195 km and the 20 km walk is third.
marathon
No word for it. A Swahili speaker would simply say "marathon.": Nimeshindania marathon, I competed in a marathon.