The best arm workouts target several major muscles at once. Tricep dips, push-ups, planks, and burpees will tone your arms and don't require weights. Exercise your upper body two to three times a ...

Your tricep muscles contract and pull, while your bicep muscles relax, causing your arm to straighten back out. You can find antagonistic pairs in your legs too. Just extend and curl and see which ...

This is why our joints are controlled by more than one muscle. For example, our elbow joint in the arm has two muscles, to move your forearm up and down. these are the biceps that pull your arm up ...