Unless you live in an empty field, there’s gotta be something you can use.
As good as calisthenics can be for working your core area, you’ll only get so far with stretching and body weight. If you want to get a proper six-pack going, you’re going to need to add some weight. Can’t break your limits if you don’t exceed them first, right? Now, when I say “add some weight,” you’re probably assuming I mean you need some exercise equipment likes weights and machines, but that’s actually not the case. As long as you can find something easy to hold that weighs a fair bit, you can get started.
Here’s how it works: find a small object you can easily hold in your hands that weighs around six pounds. Anything’s fine, as long as you can get a firm grip on it: a tied stack of books, a pumpkin, a sock full of nickels, or whatever you happen to have lying around the house. When you’ve got your weight, hold it close to your chest and lean back in the same way you’d come down from a sit-up. When you hit the bottom, extend your hands outward along with the weight, pull yourself back up, then slowly move your hands back to your chest. The added wrinkle of your extended arms being held down by the weight makes a normal sit-up much more challenging.
You can combine this method with any other kind of sit-up, as well as any exercise that involves lying down. For example, the wrap and tap, in which you lay on your back, extend your legs, and reach up to touch them, becomes that much trickier with the added hand weight. Ten minutes of this kind of exercise, preferably with a different exercise every minute, will really put the ache in you.