Doomsday Survival: Give Zombies a Treadmill at the Beginning

Zombies massacred the city, and my girlfriend ran away with the zombies! Zombies want to get in? However, my home has titanium alloy walls and ultra-high-strength glass! Don't want to go out at all? Since I have memories of my previous life, of course I have hoarded a lot of supplies! What about energy? This is not simple! There is a lot of energy outside the door! Hey, zombie, come here, this treadmill is for you! Don't think I'm such a homebody, I'm all here to save you! This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.