This is a relatively straightforward exercise but extremely good for your biceps. Take a set of dumbbells in each arm and hang your arms by your side at full length. Start the exercise with your palms facing inwards and by just bending your elbows, not using your shoulders or upper arms, curl the dumbbells (doing both left and right arm at the same time) and open outward so the palms are facing towards your shoulders at the top of the cycle. Hold, and then slowly move your arms back down to the starting position. Increase your repetitions gradually.