This upper-body classic will strengthen both your pectoral muscles, triceps, and core. It may look simple, but don't discount it as unchallenging: a Push Up performed with proper technique is the same as pressing 65% of your total body weight.
Start by finding yourself a mat or a comfortable area on the floor. Get down on your hands, arms straight, with your legs extended all the way out behind you. Your palms are flat on the ground and outside the width of your shoulders. Your toes are bent against the ground and your heels are pointing upwards. Your eyes should be looking down and slightly out in front of you.
Maintain a straight spine, so your hips, back, and head are all in alignment. Use your core to stabilize your body in this position above the ground. Next, inhale and bend your elbows in a controlled movement to lower your entire body down until your chest almost touches the floor.
As soon as you reach the bottom of the movement, exhale and push through your hands to raise yourself up again until you return to the starting position. This counts as one Push Up.
For maximum muscle activation, refrain from raising your hips or sagging your spine downwards. Maintain a stiff core at all times.
If you can't yet complete a full body weight Push Up, try a Modified Push Up on your knees until you can build up the strength to perform the exercise with your legs fully extended.