SC Marathon 42km Run?

Hello, I just had some random inspirations ~ It has always been a dream for me to complete a 42km SC Marathon Run, the most I did was army half marathon 21km 11 years ago. Wanted to do a 42km next but life happened and everything went down hill lol.

A little about me : 38 years old. Damn fat, 178cm / 105kg, it is definitely impossible to even do a 10km within an hour at my current state, but I think one goal i want to set for 2026 will be to complete a 42km next year.

I started exercising again since July, a bit sporadic, doing 2 threadmill cardio a week and only recently November increased to 3-4 times a week. So far i'm able to do a 1 hour 12.5 incline speed 3.6 easily on every alternate day, I will try to push for higher incline/speed. Here's a record of my recent exercises - https://imgur.com/a/3VvVC3y - my last jog was in May, 40mins 4.18km.

Anyone have any tips / advice on whether is it feasible/possible for me to complete a 42km run by next year? Below are my plans :

• I am trying to be consistent to go to gyms so I'm doing things at a comfortable pace, right now my target is to gym 5-6 times a week alternating between threadmill walks and cycling
• When the new year starts I'm thinking to drop a few days to go outdoor jogs at 1 hour to see what is my pace like, then gradually push for longer distance/jogs and alternate between incline walks
• Will be on the lookout for marathons / cycling events next year and join them
• Will probably aim for some 10km runs Marathon in first half of 2026 - aiming for below 1 hour before i go for 21km
• Then if all is good, 21km half marathon in Q2/Q3 2026 - aiming for less 2 hour 15mins
• Followed by SC Marathon 2026 - if i am dying for the 21 km prior to this, then I'll go for 21km in 2026 and try 42km in 2027

Anyone think it is feasible/possible for me to train to complete a 42km next year? Is there anything i should lookout for or do - like some kind of checkup or something or just bite the bullet and push for it?

*I did chatgpt and they gave me some advices, will likely try to blend them into what I'm currently doing