Then you should see the pictures of my hikes on Facebook :>)
I am an old (56) overweight (245) hiker! Went to the 8600 ft level on Mt Rainier in July.
What is the elevation you started out at on Mt. Rainier? I find that elevation gain is the main determinant of how strenous a hike is. Also, 8600' is higher than anything in this part of the country, and the air is thinner, making any exercise harder.