I am looking to build myself up by this time next year so I can go mountain hiking.

[Neonatal RRT]

Knowing the terrain up there...you'll be climbing rocky trails at high altitude...and you'll have to go back down. For your training, I might suggest farmers walks (dumbells in each hand), and up/down stairs...you'll be using those sorts of muscles. I might also suggest getting yourself a 40-50lb kettlebell and do squats every other day, or so. Work yourself up, over time, to multiple sets of 20-30. The weights don't have to be particularly heavy, but you will have to develop strength and endurance. You can do the walks on alternate days...weighted vest if you can find one.

 

[Aspychata]

Great post, getting me motivated to get back to exercise, haven't had motivation.

 

[Shevek]

In the first week, I work up to a distance and speed that leaves me a bit tired and achey for a few hours, but not overnight. I do that every day the next week. Then, I do 10% more each week afterwards until I'm about as fit as genes allow without special attention.
BTW, I used to be able to see Rainier from the trail to my house. Snowiest place on Earth.

 

[Coxhere]

10,000 steps on flat land is easy. On an incline is more difficult.

If 10,000 steps on flat land is easy, then give yourself some credit. You're evidently not as "sedentary" as you've been thinking you are.

 

[Metalhead]

If 10,000 steps on flat land is easy, then give yourself some credit. You're evidently not as "sedentary" as you've been thinking you are.

It turned out to be less easy than I thought it was. It was easier for me to do that before COVIF, but now I am way out of shape. I did 12,000 steps yesterday and I want to do 10,000 steps today but my body is demanding a day of rest.

 

[Coxhere]

It turned out to be less easy than I thought it was. It was easier for me to do that before COVIF, but now I am way out of shape. I did 12,000 steps yesterday and I want to do 10,000 steps today but my body is demanding a day of rest.

It turned out to be less easy than I thought it was. It was easier for me to do that before COVIF, but now I am way out of shape. I did 12,000 steps yesterday and I want to do 10,000 steps today but my body is demanding a day of rest.

Many don't know how to "listen to" their bodies. You are one of the fortunate ones who knows how and this is a positive for you.

 

[Metalhead]

I slept all afternoon long, now I am awake and alert and the weather outside is cooler, I might go for a short walk around the block a couple of times.

 

[Coxhere]

I slept all afternoon long, now I am awake and alert and the weather outside is cooler, I might go for a short walk around the block a couple of times.

Sounds like a winner as well as a walker!