For me, the gold standard is what I call a "proper trudge", which is a six mile walk with 1000 ft of elevation gain.

I credit myself with 100 calories/mile with a bonus of 50 calories per 100 feet of climbing. A proper trudge (PT) burns 600 calories for moving forward, and an additional 500 for moving up.

I lived in Placentia for 2007-2013, and my favorite PT was in Chino Hills State Park. I would hike three miles up the North Ridge Trail and get my 1000 feet of climbing in, and then turn around. I could do it generally in under 2 hours when I am in shape.

These days it is Portuguese Bend. I park at the end of Forrestal at the Ladera Linda park office and then hike to Del Cerro Park. Just under 3 miles up and about 1100 feet, so the round trip is a PT and an easy 2 hours.