Can't do a single push up!

I can only do a few and then I'm done. I have the information for the 100 push up challenge, just haven't started it yet. I work in plank position a lot and see how long I can hold it. Or a new favorite, hold plank position and then touch my left hand to my right, and then back to center. Then right hand to left, and then center. And that would be 1. Continue and do 10 of those. That will at least help build your arm muscle and endurance and then you can try push ups. I tell myself to do at least 1 push up a day because that is more than I normally do. And my motivation is that every bit counts.
Good luck and give it a shot!!

We're all at different places on our fitness journey. Start laying on your stomach. Then come up to arms length with your knees on the floor if you can. If not, just keep at it every day until you can. That's called a plank, the push up's kid brother. Hold yourself up in a plank as long as you can. Don't be afraid to quiver a little, it builds character. ;-) You can move to planks on your toes if you want, or stay on your knees. Eventually, from a plank with your knees on the floor you'll be able to lower yourself, then come back up and guess what, you just did your first push up. From there, do more, and even more, then try one, just one, on your toes and remember today when you couldn't do any--you'll get there--if you choose to do so. It's in all of us to achieve nearly anything, we just have to want it and to believe we can do it, and then...work up to it. Be sure to post when you're doing spider push ups and don't feel bad if you don't get to one armed push ups, even I'm leaving that to Jack Palance and the young ones. ;-)

I feel you!
i started NROLFW today and i had to do 2 sets of 15 pushups!
I did 2 sets of 10 pushups somewhere inbetween girly and boxpress.
And those were hard! Just keep at it, with time comes strenght.

I also really struggle doing "proper" push ups. I'm gonna build them up, and hopefully i'll manage them eventually. I'm also doing Insanity and i havent done the push ups alot of the time but i can defo feel a difference. Keep at it!x

I'm sure that pushups are just really hard for some people. I couldn't do them at all when I was young, fit and slim. I can now do them (while obese), but that's after working on them for a year! I suspect they are particularly hard if you don't have either good upper body strength (me - I'm also bad at the bench press) or good core strength (to keep your body aligned).

Anyway, obviously during that year that I was trying to do pushups and couldn't, I lost weight, so no, you don't need to be able to do pushups to lose weight!

I tried against the wall, but then again, after a couple of them, I get exhausted.
I tried on my knees, it seems it puts a lot strain on them...

You got exhausted? Good!

Try for 5 sets of 20. If you can only do 5 in the first set, that's fine. If by the time you get to the 5th set you can't do anymore, awesome! You're muscles are going to get really strong, don't worry about it.

Keep doing it until you can do 5 sets of 20, then move down to the kitchen counter. Do them every other day, keep track of your progress on a piece of paper. Tape it to your fridge to remind yourself how awesome you are.

Knee push ups are not an effective intermediate for real push ups, they don't engage the same core stability muscles. Plus they're really bad for your knees, especially if you're overweight. Don't bother with them.

Start on your knees with "girl push-ups."
I did girl push-ups for 5 months then finally decided to try real ones again....and BAM! I did 20 standard push-ups in a row.
Start with something simple and work your way up to the real thing.

I lost 100lbs without doing a single push up. Hell, a simple 15-minute yoga routine and basic walking on the spot was all I did for the first 3 years or so due to restrictions of body and mind.
You'll be fine! I couldn't do one military push up at all last year, now I can just about do 3 sets of 12. Which for me, is pretty good. Anyway, start with a wall, then use your knees when that's too easy (on all fours, I mean) and build up. Lift heavy things too. Do what you can and be patient with yourself. It's amazing when you look back, if you do.
Good luck.

1) up against a wall; after a few weeks and building a little strength in my back and upper arms,
2) I moved to my kitchen counter. Put your hands on the edge of the counter and push up. You will feel the affect
3) I then moved to a park bench or tire (the size off a semi truck...we have them at the gym). Again ... you've built up stronger arms and back from using the wall and the kitchen counter ...

This is a great progression. It's better to to incline pushups at whatever level you need (wall, countertop, etc) than to do them on you knees.

Here's some hope.....I couldn't do one proper form pushup this time last year. Now, I can knock out a set of 25 easy. When doing shorter sets, I have to make them harder now either by adding resistance with a band across my back/shoulders or my elevating my feet on a bench.

It's possible. Stay consistent and you will progress. Remember: form over speed! Don't try to keep up with the folks on the Insanity videos. Pause the video if you have to. Quality over quantity. If you aren't doing them properly, then consider it a waste of time. You'll be using some muscles, but wouldn't you rather use all of the muscles the exercise should use?

ETA: Sure, you can lose fat and gain strength without doing pushups, but they are, in my opinion, pretty badass. Especially when you start doing more advanced versions, like one arm or single leg push ups.

Also, you should start with a beginner exercise program before Insanity.