Ask HN: How did you start exercising after being completely out of shape?

On habit consistency - start small. People get super depressed because they didn't work out three times that first week. Start with once a week, see how that works for you. Can you build in a second time that week? Do you need to change what time you do the activity, like before work instead of after? Try that and see how it works for you. Make things easy for you by setting your clothes out the night before so there's limited inhibitions on doing the thing you want to do.

You'll also need to find something that you enjoy. I'd personally favor a less optimal workout (in terms of working muscle groups, not increased risk of injury) that you enjoy over super-max-get-shredded-tomorrow that's a slog. You'll slowly build into it. For me, my activity was martial arts, I moved away from the dojo and got into weight lifting. I really didn't care for bodyweight fitness, and would find myself looking for excuses to skip or cut the workout short. Be careful when you compare yourselves to others, they could be much further along than you and had different constraints.

The third thing is diet. There's tons of articles on proper diet, and for me that's too much stuff to get into at the beginning. What I did was write down and calculate calories for two weeks at the beginning. The first week I ate normally how I felt like. The second I tried to make slight adjustments, still within the realm of things I would eat (basically the "eat this not that"). Those changes were enough for me to get to my desired calorie intake. I don't count macro nutrients, I don't weigh food. It was super intimidating to jump into that, and I didn't want to drag my significant other into my food changes. That being said, maybe entering everything you eat into MyFitnessPal or similar would be helpful for you. Maybe a defined diet regime with preplanned meals is something for you. A friend of mine pays for FancyHands or similar and just sends pictures of what he eats to them and they'll rough out the calorie count into his calorie tracking app. My relative preps everything on Sunday for the week, weighs food, and will not deviate from the diet even for the holidays. It's a bit of an experiment, going back to consistency of habit and something you enjoy.

I'd check out /r/fitness, /r/bodyweightfitness, /r/MealPrepSunday/, Strong Lifts, and maybe 4 Hour Body (a friend of mine swore by it, lost 25 pounds) as just different resources you could expose yourself to. You could also decide to do martial arts or basketball or tennis or whatever other sport.

Move. Just move. I started going for MWF 5k walks, they took almost an hour at the start. Pick a shorter distance if that's too intimidating. A lap around the apartment complex at my old place was 1km. Do that once or twice each night after dinner. Make this a habit, a routine. If it's not, you can't take the next step to making a weight lifting or sports routine.

I also played soccer, badly. But I was moving. I'd give it all I had, get gassed, sub out, come back, repeat. Pick a sport that you enjoy and do it. Especially if you can find a group you like to play with. Going to the games was as much about seeing and being with my friends as playing the game itself.

Diet. My initial massive weight loss, I also quit sodas and candy. I eat and drink those now, but in moderation, as treats. This made the first 20lbs fall off fast.

Don't get frustrated by lack of weight loss. I'm back to 200 lbs (220->170->200 over two years). I got stuck at 195 on the way down. But I also added in BJJ which built up some extra muscle at that point, so I was trading muscle for fat. The way back up, it's been strength training (bodyweight) that's built up my chest and arms. I'm still fitting into 33" waist pants, so those 30lbs have been useful (170 was also too low for me, I looked emaciated, 180 if I'm just running, 190 with BJJ, 200 with those and bodyweight training are about right).

Accept that you may have many false starts. I "took up" running once a year or so for 5 or 6 years before it stuck. I took up bodyweight training with about the same frequency of starts and failures. This will be frustrating, but keep trying. And try new things. If you can't stick to the activity (for reasons other than injury or severe time pressures from other obligations), then you probably aren't enjoying it. Find something else.

Listen to your body and have good partners. I do BJJ, it's dangerous (NB: if everyone does everything right it's fine, but an armbar can easily screw up someone's shoulder or elbow if done wrong or taken too far). I started with a shoulder injury (soccer accident, body slammed by a teammate and landed on the shoulder). I didn't use that arm much. I tapped as soon as someone got it in anything resembling an armbar. I talked with my partners and told them the limits of my body, and they respected that. They'd avoid that arm during drills (or do it very light) and rolling. If you do something like this, and you don't have respectful, considerate classmates and instructors, FIND A NEW GYM.

Activities that can be fun to start with that get you some exercise, but you'll want more to get really fit and strong (if strength is your goal in particular):

Walking - easy to do, aim for 30+ minutes at a moderate pace to start. Then start shooting for distance once the 30 minutes is easier, and then reduce your time on that distance back to 30. That's why I do 5ks. It took me 50+ minutes to walk the distance, started jogging and got it to 40, started running and got it to 30.

Cycling - this will get you fit on its own. It's easy on the joints, slightly expensive (need a bike) and harder to do in inclement weather. But do the same as walking: 30+ minutes, then distance, then reduce the time back to 30-45 minutes (or whatever you can afford) at that distance.

Hiking - requires travel, but as almost as easy as walking, and probably more interesting scenery. Can be a fun social activity as well (let's go to the mountains this weekend!) or, if it's located near where you live, a nice thing to do with an SO paired with a picnic or something. Making being active fun is really helpful for sticking with it.

Dancing - ballroom, tango, they're challenging but fun and will help with impressing your partners in the present or the future. These can be harder due to needing to learn new skillsets and ways of moving and keeping time, but it's effective. Turned out to be useful when I tried my hand at boxing, too, with understanding how to stay light on my feet, control my balance.

It really helped that my apartment had a gym that was available to me practically any time I wanted.