Where are my chest muscles?

I believe smerdons you missed one very important point that swanso pointed out. Pushups use more muscles in the body (even doing 1/2 pushups [negatives]). By using more muscle you will build more muscle and also burn more fat then and in the future from the muscle you have gained.

Also, by utilizing the core muscles with a pushup that are not used pretty much not at all with a bench press, you are strengthening the muscles that will help with posture and help prevent injury in the long term. Remember, overall body conditioning is far more important healthwise than how much one can lift or how many pushups, setting goals to achieve by these standards help track progress and motivate us to each new level of fitness.

As far as a 400 lb morbidly obese individual, I would first have a doctor check him, then help with diet and basic walking excercises. Much more would probably increase the morbid part.

I hope this helped.

cheers

PS. Now that you've been working with the bench press and increasing there, you really should try pushups again for the core aspect of the excercise. See how many reps you can do for 3 sets. You probably will find your shoulders, abs and lower back will give out long before your pectorials.

400 pounders would be advised in my way of thinking, to change diet and do some mild Cardio, about 5 times a week, splitting the off days, 3 on 1 off, 2 on, 1 off, increasing a little in intensity each week.

I wouldn't suggest anyone like that be given weights initially, incase their dietary problems had affected stuff like Bone density, so no resistance work at all initially, push-ups or Bench Pressing included, because bearing weight on any small joints with a Push-up, even things like a Knuckle, might be an issue if the Bones have a poor density.

Dietary changes and monitored Cardio would permit some weight loss, and allow for better promotion of things like Bone health, then when the individual had lost maybe 80-100lbs, then scored higher than -1 on a T or Z score, then go for weights, with a TBT adaption system for 4-6 weeks, followed by more intense TBT or a basic 4 or 5 day split.

Thanks for all the feedback, guys! I think I'm finally starting to understand that advice. It just needs to be expanded a little bit to include 'if you are in any condition to be lifting weights...'

Good call Smerdons, especially for people who might be quite slim but eat lower calorie diets than they should, as they could have issues with Bone density, and might not even be advised to even do Cardio, incase it affected the Metatarsals and Ankle area, not without changing their diet first, to hopefully include more minerals / vitamins relevant to Bone health.