Somebody mentioned squats, doing knee-bends with an Olympic bar with anywhere from 5 to multiple 45 pound plates on the back of your shoulders.
I do them, but I think doing them for repetition's might be better than trying to do a lot of weight one time?

I climb 353+ flights of 20 steps each month. 30-ish flights a day on the days I am in the office. Up and down.

Why 353 flights of 20 steps each month?

We measured it and 353 flights of 20 steps in our particular 11-storey office building is the equivalent of the height of Mount Wellington which stands behind Hobart.

A small group of us have been "climbing Mt Wellington" each month, most months. Some months we don't make it because we're on leave or something, but most months we do. And once in a while, we climb more. We've got several other "mountains" we can climb to if we're having a really good month. We also try to "Everest" once or twice a year (adding up several months).

In January, I climbed 380 flights. Last October, I climbed 516 flights.

Often people assume that we run the stairs, but of course not!! We're older people and would rather not twist a knee, ankle or hip. We walk at a steady pace. If we haven't done it for a little while because of leave or something, we'll walk slowly but if we have been doing it for a while, we'll pick up the pace.

I find that climbing up stairs helps me be a better hill climber on the bicycle.

Walking down stairs strengthens my calves. BTW, if you go a little faster down the stairs and stay on the balls of your feet, your knees don't feel it as much.

And since we lose weight by breathing out, it helps me maintain my weight or lose if I increase the number of flights of stairs.

I live in Tokyo, which is not an "accessible" city, and therefore has lots of stairs. People often wonder why obesity and diabetes are rare in Japan. It isn't the diet, it is the walking and stairs.

When I started working for a Japanese company, I lived in a company dormitory, on the 3rd floor. There was no elevator. I'd leave at 6 in the morning, walk 20 minutes to the train station. I had to take stairs and a walkway over the tracks to get to the station. Once inside I would have to take stairs and another walkway to get to my platform. The 6:30 train for Tokyo was an express, the only one from my area, so it was packed. I still had to change trains in Soga, which meant two more flights of stairs, then another crowded train to Tokyo Station. The train platform was 3 levels below the station, so 3 flights of stairs to get to the station proper. Then walk underground through the station to Otemachi, where my office was located. It was 4 floors up from the B1 level. I would be at my office by 7:45, giving me 45 minutes to relax with coffee and breakfast before the day began.

During the day I would often have to walk or take the train to the offices of clients and/or vendors. These were sometimes quite distant. The work day ended at 9:30 pm, then I would do the reverse of the commute described above, adding an extra train as there was no express at that hour. Each day meant at least 20 flights of stairs, and 2 or 3km of walking.

Yes, I'm talking about barbell squats, shooting for being able to squat one's bodyweight. For instance, I weigh 155 and I'm currently squatting about 120 lbs for 10 reps, and I'm 80, hoping to work back up to 155 over the next few months.

Of course, I have a history of working out, off and on all my life. I started doing mile runs when I was 12. I used the gym when I was in college and was on the Nordic XC varsity team. I could do over 200 one-legged squats on each leg. The month before I went in the Army at 20, I'd hiked 300 miles, sorta by accident. I then had a long period of no exercise other than being on my feet doing manual labor until I was 50 when I rediscovered cycling. After I got the hang of riding long distances, I started with the gym again, wanting to get stronger on the bike. That's just MY history. But that worked and the older I've become, the more I've realized how important that strength work has been for me.

One starts by doing stretches every morning and doing unloaded squats and pushups, trying to get loose enough and getting enough mobility in one's ankles to be able to do a full unloaded ass-to-grass squat, say 20 reps. That might take a few months, depending. One then starts squatting with just the bar, 3 sets of 12. When one no longer cramps after doing that, one gradually adds weight. Getting to squat one's bodyweight could easily take 3 years of once a week pushing exercise like squats, anything that involves moving the weight away from one or the floor and one day of pulling exercises. Using one's full range of motion is very important. And one doesn't have to start using only 10-12 reps. It's actually better to start with 30 reps and gradually taper down over the years. 3 sets of 30 is a great workout, keeping the heart rate up and not taking long rests between sets.

If you look at medical journals, there's always an article saying that the way to not get injured as one ages is to do strength work. Beyond avoiding injury, I want to be able to do anything I want to do with my body. I like freedom. I can ride, run, backpack, essentially being able to train myself up for anything. That's freedom. I'm really big on that. There's a very popular book out there, Freedom of the Hills. One can work up to doing quite amazing things. I've met folks in their 70's hiking the PCT end to end in a matter of months.

I certainly admit to being more active than the usual American. However, age does not have to mean defeat, becoming less active. Nah, it's true one doesn't have to do strength work, only do it if one is interested in staying active and not falling and breaking something due to age. That's basically The End, when on falls and breaks a hip. First one falls because one's balance isn't so good because one hasn't practiced balancing. Alway dress and undress while standing. One should be able to do everything while standing except tying one's shoes. Weakness and lack of balance sooner or later leads to stumbling, and stumbling leads to falling, and falling while not having strong bones and connective tissue leads to injury. This is not rocket science.

In fact, the reason my wife and I bought bikes when I was 50 was that I'd stumbled on the way to our mailbox. I thought, "I don't stumble!" IME, taking the stairs isn't going to be enough, though it certainly is a good start.

Agreed. Use it or lose it. That deterioration is avoidable. My wife and I still do 10-day backpacks in the Cascades, pain free, not counting being sore!. Neither of us is actually "athletic." We just work hard at it. This year I'll be 81 for our backpack. The only issue is conditioning. Everything works, we just get tired sooner because it's harder to get into and maintain fitness. A week off and it's gone. It's just strength work and conditioning. Never give up. That said, once it's gotten that far, it's probably too late. There was a way out of it.

BRAVO!

Did I read that correctly? Are you 80? That's outstanding. As for lifting weights and being active, there really is a benefit. I'm not like you, I'm just an average guy who has kept lifting weights since high school.

You're probably like me. I'm a duffer. I'm the guy who tripped over the basketball trying to dribble in HS PE. My talents are that I'm smart and I don't give up. Analysis and follow-through. Over time, that becomes more important than physical talent for some simple things. I still can't catch a baseball. Aerobically, my analysis talent turned out to be more important than talent, too. I figured out how to train. Oh, I do have a skiing talent. Don't know what that's about, I'm just good about weight placement and balance. I also had an odd talent with Nordic skiing - I have a good sense of how hard I can kick without slipping. It's weird and I don't understand it, it just is.

Might have something to do with growing up in rural Fairbanks, where when I was like 10-14 y.o., in winter I'd leave the house in the morning on skis and come back hours later. TG my parents never knew or seemed to care what I did and where I went. I did the same thing on my bike in summer. So my talent is desire - a love of freedom. I got that from my mom. There's a famous text, The Freedom of the Hills, which later became my bible. I was always terrified of heights. The third rung on a ladder was scary, so in college, I took up rock climbing. I have a good memory of bawling my head off when I was having trouble making a move with lots of exposure. Cured myself of that fear. Later climbed in Yosemite - I was lousy at it but I loved it. Kinda the same with cycling. If one does enough of something, one gets better at it. As a kid, my mom made herself a pair of wings and jumped off the barn. Broke her arm, but she did it.

Thinking more about the OP's question: My wife had an aunt who owned her two-story house. She lived on the second floor, rented out the first floor. She had a narrow winding staircase up to her door, quite tricky, but that was a good thing. She had to carry groceries, etc., up those stairs. Her husband was worthless. The stairs made a difference. However she got bad ankles, probably from not walking enough. She loved to shop, so she got a prescription for 6 weeks of therapy, fixed her right up, but she knew she'd deteriorate. We advised her to join a gym and she did. She hired a coach and went at it. She loved it, flipping truck tires, deadlifting 90#, etc. Fixed her right up again. We noticed how much help having stairs had been to her, so when we retired from boatbuilding, rather than sell the shop and buy a house, we kept the shop with our upstairs apartment, which had an upstairs bedroom and living room, etc. I bet we go up and down those stairs like 100 times a day. It's noticeable. So many of our friends made the mistake of moving into single level houses as they aged.

I went out for the football team back in school.decades ago. I was just a middling average guy, not a great athlete and not very big. Back then weightlifting wasn’t a big thing. I started doing it , and somehow I actually got strong . Suddenly I found myself 40 pounds heavier , and on the offensive Line, and I was driving people way off the line and could get off the snap quickly. To add to the comedy, I was actually the fastest lineman on the team. And being scholarly I picked up little things like how my opponents positioned their hands and feet and l could figure out what the scheme was. Guys who used to laugh at me were scared of me. Without lifting I would have been the water boy.
To this day it’s an habit, but I certainly use less weight now

Yes, for 3 reasons.

1970, 16 year old me has just delivered mom her daily fresh laundry. Mom was hospitalized with spine surgery.
Riding the elevator down, stupid thing got stuck, for Twenty-Freakin-Minutes! Thankfully, just me in the elevator.

1) I am never getting those 20 minutes back.
2) I firmly believe that running the motor that lifts and lowers that elevator car is a waste of electrical energy.
3) Stairs are part of my fitness plan.

There are stairs?

No elevator in our house and the steep driveway is a PITA.

This past week I skipped the elevator twice and took the stairs in my building where I live. I live on the 12th floor so I walked 12 flights of stairs, each flight of stairs has 14 steps. I also take two steps at a time and make it more like a walking lunge.

I'm 84 with a 3 year old Total Knee Replacement. When I go for a 1 hour walk in the park, just a quarter mile away, I do 300 to 400 steps.

Not if I am carrying my bike.

If stairs are readily available and not more than 5 floors, I always take the stairs. Very complimentary to cycling.

I live in an apartment building built in about 1917. It was a warehouse building, converted in 1976. The stairs are steep and treacherous so I don't walk up them often at all. But I choose stairs almost everywhere else. I always walk up stairs two at a time, and I think this has helped me stay relatively strong. I didn't cycle much at all when my kids were young, but I took the stairs a lot at work, sometimes racing the elevator. I think it helped me when I got back on the bike, as I was still fairly good at it.

Now I work on the 5th floor most of the day, and I go up and down a lot. My watch/phone say I climb 10 to 20 flights a day. They also say I descend more slowly than I climb, and it does seem that way. I should do some leg lifts or whatever it is that helps going down. The kids at the high school where I work might think I descend like an old man. And yes, I'm 65.

In recent years, until December, I was in college and grad school in a high rise building. I often climbed up to the 10th or 12th floor. It wasn't just for fitness; it was also because the elevators and escalators there are unreliable and slow. I'd rather go slowly at a predictable pace than waiting for an elevator and not knowing how long it will take.

So yes, I do like climbing, and I think it helps!

Yes. Can't understand all the young people at my university who take the elevator to go up 2 floors.

The next question: Do you place your whole foot on the step or just your toes? I was a toes only, than became a slacker until I climbed the circa 1900s very narrow tread stairs at my son’s house and converted back to toes only.

This 83-old lady could only walk for 30-seconds before starting strength training and now she can walk over 10-minutes, including walking uphill. And she's still improving.

This shows just how important muscle is, which we all start losing around the age of 30.

Very good question. I use my toes (and really the balls), as I know it adds work to the motion. Unless I'm feeling unsteady. And that leads to another important thing: balance. I tie my shoes by standing on one foot and holding my other foot up to my hands. It's good practice.

That is an excellent thing to do. A few years ago I rented ski equipment at a resort, and upon returning the boots was balancing on one leg tying my shoe when a woman commented something to the effect that, Wow you have excellent balance.

Meh - I take the elevator. I'm on the third floor at work - elevator.

I ride plenty, get plenty of cardio. I'm lucky to carry muscle and retain strength - for now, at 54, I have zero concerns in that department. So the elevator is a nice luxury that I enjoy.

I envy you guys. Fine balance is something I lost with my head injury. Never came fully back. Doing that exercise would have improved it; but at the cost of falls. My life quality decision - skip that and reserve falls for the bike.

And to the topic - using elevators. I hope to high heaven that next time I fly, the if the pilot chooses to bypass the elevators, he uses the rudder and ailerons, not the stairs!