Start on the ground with your arms straight and your weight on your hands and feet. Focus on keeping your abs tight and your body as straight as possible from ankles to shoulders. Stop if you feel pain in your back or if your low back cannot stay straight. Bend your arms to lower your body towards the ground as far as you can control the movement. Then push your body away from the floor until your arms are straight, but not locked.
To increase the difficulty, move your hands closer together, which puts more emphasis on your triceps and other arm muscles. Perform up to 15 reps and breathe out when you are pushing away from the ground.
If you are not able to maintain a flat back throughout the movement, it means your stabilizer muscles are not strong enough to perform it correctly yet, even if your arms/chest/shoulders are strong enough. If this happens, perform kneeling push-ups until your abs/core improves. (see Donga Workout – Beginners)
Safety Note: Push-ups can be hard on the wrists, so if they feel uncomfortable, you can use a different hand position. A common change is to perform push-ups on your knuckles instead of having your hand flat on the ground. A more advanced option is to perform them on your finger tips, but this is tough on the fingers. You can also use padding, such as a towel to make them more comfortable.