Probably close to a day while camping in the mountains. Wow, memories of fresh air and pine trees with little critters scampering about. Now just making it to my car is difficult.
Continuously means no sitting or resting. I'd say around 6 hours. From the freeway, around the valley, up to the top of the mountain and then back down to the car. I was in search of a shoe insert my dad left somewhere on the mountain on his hile the day before.
So are the custom-made ones you get from a podiatrist. My point is I wouldn't go looking for it for six hours. If he could hike he could hunt for his orthotic....that's how I would feel about that.