There probably should be an "I don't" option. C'mon, I can't be the only person with dumbbells covered in cobwebs, right?

I have my road bike hooked up to a trainer right by my desk. Works super well for watching interviews and listening to podcasts.

(A bike trainer essentially converts your 'normal' bike into a stationary bike. http://www.amazon.com/b?ie=UTF8&node=3403551 )

Rock climbing is awesome! It's safe. It's a full body workout. You can do it both indoors and outdoors. No pressure, relaxed and noob friendly environment. You don't have to be very strong and the don't need gear to start. Renting gear at your local gym will do. Progress is measurable (as you get better, you'll find yourself doing higher grades of climbs).

All you need is a partner (guy/gal that you trust) and a local climbing gym. Go sign up for intro courses, that'll probably only take a day for the basics. It's really simple. The Boston area has metrorock.

Also, hackers will definitely make the connection between solving a "problem" in a route and regular problem solving. Most good routes (especially boulder problems) have a crux, where it's really difficult, but the way you get past is usually not by muscle-ing through but doing some unintuitive move that takes a leap of imagination and creativity. After some trials, you'll get the "aha" moment.

There's bouldering, which is low-height, and you fall on a map. A little more muscle strength required. There's also toproping, where you're climbing high walls but are protected by rope, and a partner belaying you from below. There are a few more styles that you can google if you really want to, that are not quite for beginners.

Tips (that you'll ignore anyway but then remember in the future):

- It's all about the fingers. After your first day, they will be very sore.

- Body positioning and movement is very important. It will reduce your tiring rate, and get you past positions where you can't quite get to the next hold. Watch other (advanced) climbers do their thing. Most won't mind. See how they move around fluidly and gracefully, and try to imitate that.

- Muscles will help later on but initially it's not as important as the stuff mentioned above. I have no muscles and I can pull of a decent 5.10-5.11 (ratings start at 5.6-7, and almost exponentially increase in difficulty to 5.15 for world champs.)

- Start easy, and try not to go up levels too fast. Many beginners fall into this trap where they already have lots of muscle and they can power through to the higher ratings. This is cool, but if you find yourself doing tons of arm-wrenching pull-ups and slamming your feet and knees into the wall, time to lower a level and practice a bit more until you get the sequences down perfectly.

- Practice falling. It'll reduce your fear of falling, and give you that extra boost of confidence to do that freaky move.

I like weight exercises with dumbbells because it's easy and cheap to get everything you need to work out at home with some adjustable dumbbells.

Swimming is great cardio, but harder to do at home without a pool :-)

Really, no shovelglove love? http://bit.ly/9OuEbd

I've been at it for a year+ and it's incredibly effective. It's sort of a modern take on the Müller system [http://slate.me/gDHIsE]: ~15min daily, varied movements, rinse & repeat.

Its analog, the No-S Diet, is also pretty awesome: http://bit.ly/fJL33Z

Yoga, 2-3 times a week. Motivation: I enjoy it. But, I'll admit taking a class also makes me commit to showing up regularly and on time.

Stopped using the car and started going (almost) everywhere by foot and public transport. I probably end up walking about 1 or 2 hours per day.

The best motivation is the fact that I save money, don't have to worry about traffic, and feel more awake after walking. The physical fitness side of it doesn't concern me that much, even though I know it should.

A combination of all of the above. Learn to enjoy things that get you active, and you wont have to worry about exercise.

Cutting firewood. I enjoy all of the above sports but usually can't find the time for them. The one activity I HAVE found the time and motivation for is cutting and splitting firewood to stockpile for winter (I live in central Pennsylvania). There's a saying: "Wood warms you twice -- once when you cut it and then when you burn it." When felling dead trees in the woods and then carrying out the large logs, your leg, back, and core muscles get very strengthened. Later, when splitting the logs with a large maul ax (I use an 8lb head), your shoulders and arms get a huge workout.

I am motivated because I can satisfy several objectives simultaneously:

(1) Getting and maintaining all-around top physical conditioning. (2) Spending hardly any money on heating costs. (3) Interacting directly with nature to better understand and appreciate it.

Plus, fireplaces are the best.

"Walking is the best possible exercise. Habituate yourself to walk very fast." ~ Thomas Jefferson

I think you should have added "gym" as an option. I spend a lot of time on the elliptical trainer because you can balance an iPad on it while you work out - but I don't really consider that 'running' as I assume that means real running outdoors.

I've been doing P90x, and I love it. It's not your typical exercise from an infomercial.

same. I did the 90 days last year, and after that just went down to the chest/shoulders, plyo, and back/biceps days from the second phase for maintenance.

works great if you maintain a healthy diet, and you only waste an hour or so three-four times a week.

I run 5-6 times a week. For me it's instant stress relief, and the best path to a clear head. I've solved countless frustrating problems while away from my computer running outside.

Running; using Jeff Galloway's book, "Marathon!" as a guide to pain-free running. I like the ability to walk out my door and start running around the neighborhood.

My office has a physical trainer that does a one hour interval workout twice a week. We rotate through stations constantly and each workout is different so there is no boredom, only griping.

I really should do at least one more day of excercise, but it is hard to find motivation by myself most days.

In previous years I was a medium distance runner (ran 5k and 10k races, finished around 50th percentile) which was great but hard to keep up during the winter (Chicago).

I walk everywhere as much as possible; when that's not possible, I bike. If that's not possible, I take a bus and then walk. It represents a huge amount of time "wasted" in transit, but I find that it helps me clear my mind and appreciate other things, like a sunset or a nice sky.

Sometimes the de-stressing is worth more than the exercise!

I also selected "Other" because I do push-ups and other assorted exercises/stretches that don't involve weights.

Climbing (indoor, almost exclusively bouldering)

I don't get nearly enough exercise. Last fall/early winter I was hitting the Bowflex 3 times a week and walking about 4 times a week. Was feeling pretty decent, but it got cold and I quit. These days the only exercise I get is Disc Golf. Plenty of walking, but it's not terribly strenuous other than that.

I can only stand running for 5 minutes. Granted, I run on the treadmill which is pretty boring but running outside doesn't appeal to me. I favor Pilates as a way to sculpt my body. Capoeira is also useful, but only for those who are physically able to handle intense muscle strain and cardio endurance.

Crossfit. Anyone else?

+1. Most efficient program I've ever seen. We have lots of lawyers and finance people in my gym so it draws people with little time and a tolerance for abuse (which should make it perfect for startup people).

Been doing crossfit with the paleo diet for the last 5 months. Lost 40lbs so far and never felt better.

I run 8 miles every other day during the week, and 10-15 on sunday (doing slightly more right now because of the LA marathon coming up)

Off days I do weight training. I need to get a kettle ball and try that. I also need to join a gym again.

I also lug around a 25 lbs toddler sometimes. And chase him.

I started refereeing soccer recently. It's a more appropriate outlet for my desire to be on the pitch than coaching. As an athletic activity it requires the same type of focus, study and training which I loved as a player.

A colleague of mine and myself have a joint personal trainer session 3 times a week. Being a joint thing we both save some money plus its a lot more fun with the three of us there to joke around with between sets.

I do bboying. I love to dance. used to do it 3 hours a day, 5 days a week for a few years. these days i only have time for a couple hours a day, 2 or 3 times a week. Planning to up it back to about 4 days/week.

I just got back into running after about a year away from it and I'm not sure why I ever quit. It's amazing how much more productive I am when I go for a 30 minute run at lunch instead of sitting at my desk.

Depending on the season, I tend to focus more on:

Winter - Kettlebells Spring - Running Summer - Tennis Autumn - Biking/Hiking

This way I never get bored of any of those disciplines and are able to maintain a pretty healthy lifestyle.

Brazilian jiu-jitsu, three or four times a week. Practices often involve conditioning, sometimes do circuits afterwards.

What keeps me coming back is skill progression and the satisfaction of doing something hard.

I row comparatively against Ivy League schools. Those 2km sprints will wear you out like nothing in your life ever will, let alone a 3 mile head race. Plus gym whenever we're not on the water.

Running [to catch buses], walking [because I missed the bus], and stair-running [to get to my next class]. Not sure if the yoga required to sit in the lecture hall seats counts.

I unicycle for exercise. It is a fun sport, with about the same exertion as jogging, but low impact. It took me about three weeks of 1-2 hours a day to master the unicycle.

I've only ticked 'weights', but I also run and climb as I can fit it in, and really want to take up brazilian jujitsu again once I'm back stateside.

I have a rowing machine with a laptop set up next to it. I can spend as much time reading HN as I want, as long as I'm exercising.

Installed a pullup bar on the door at work!

i recently bought a fitbit and wearing it everyday encourages me to walk more than i would otherwise. the growing flower icon on it is good positive reinforcement.

when i ride my bike long distances, i use mytracks on my android phone to track my course and speed.

Triathlon training is great (swim, bike, run) even when no triathlons are on the horizon.

Martial Arts

what sort.. does this really work? Doesn't seem overly cardio to me...

I dance capoeira, and although it isn't full-bore cardio, you spend enough time in the right zones (over the course of an hour) for it to count. Plus, it's good for all-around strength training. I didn't start out with any extra weight, so I've put on a few pounds of muscle across all the major muscle groups.

I do judo. It definitely works. I have better cardio, I'm stronger, more flexible, thinner and more confident. And it helped and inspired me to lose even more weight and try out other sports as well (alongside judo). Having a good trainer, and a good group of colleagues, helps a lot.

Bujinkan (japanese budo, similar to jujitsu ) I've been in more than one school and the most recent puts a big emphasis on fitness, with fitness tests every few months. Depends on the teacher/dojo more than the art, I reckon.

I had a friend quit training with us for a couple months and he can no longer keep up. I lost at least 10lbs in the first six months of training.

Depends on how you train.

Taekwondo and Judo

Soccer match once a week (indoors during the cold season)

running a little, walk/hike a lot, 3600km over the last 2 years, aiming for 2400 this year. weights a little, bit of swimming ~ high frequency, 5/7 days.

My hobby is Olympic weightlifting. AMA.

What's the most you've ever lifted?

Snatch: 110kg (~242lb), clean & jerk: 130kg (~287lb)

I've barely missed a 120kg snatch. I've cleaned 140kg but not jerked it.

I'm training for a competition in late March, aiming for 130/150.

Where's walking? I walk tons each day.

I play soccer twice a week :)

No exercise. How many don't?

love my elliptical

My answer: by moving my body, for free, in various kinds of open volumes of space, whenever I make time for it. Which is how pretty much everybody should be doing it. Not hard, not complex, not expensive, and exactly as time consuming as you'd like it to be.