Push-ups are a staple among fitness enthusiasts and drill sergeants. Using only body weight as resistance, this simple exercise effectively works out the chest, shoulders, arms and abdominal muscles without the need for weights or equipment. However, there are different schools of thought when it comes to push-up speed and technique, all of which relate to how your muscles are impacted by the exercise and how these muscles react. Rather than one being better than the other, slow and fast push-ups are actually two completely different exercises.
When you do push-ups quickly, you inadvertently harness the momentum of your up and down movement to lower the impact the push-up has on your muscles. When you do push-ups slowly, you're allowing your muscles to completely expand and contract as you go through the motions of the exercise. This builds muscle more quickly and more evenly than going fast.
Breathing properly during exercise is almost as important to muscle toning as the exercise itself. Your muscles need oxygen to grow and thrive, especially when they are under the serious duress of constant exercise. When a person does push-ups too fast, they tend to let their breath come in quick gasps or even hold it completely. Slow, methodical push-ups force you to breathe in and out rhythmically, getting the proper supply of oxygen to your muscles to keep them healthy.
Strength vs. Cardio
Essentially, fast push-ups become a cardiovascular exercise rather than a strength exercise, focusing more on calorie burning and heart rate than they do on building muscle. Slow push-ups mimic the motions of a bench press, with each muscle group being affected at different points in your up-and-down movement. Strength training will always rely on slow, deliberate movements to fully expand and contract the muscle, rather that quick, jerky bursts of resistance.