Grip strength is a key aspect of strength training. Strengthening your grip will not only help you to pull greater weights, but thicker, stronger forearms will make you appear more defined and muscular. Using any type of resistance exercise, you can strengthen your hands and arms. There are several exercises out there that will help build strong hands and forearms. Try some of these out: The hand grip is a great exercise for building muscle mass in your arm pit. Start by sitting down with your legs out in front of you. Place the handle of a dumbbell between your knees. Now lift your shoulders back so your chest is exposed. Stick your chest out as much as possible while keeping your shoulder blades pulled together and down toward your hips. You should now be in a seated position with your elbows bent 90 degrees and the weight resting on your knee caps. Now keep your elbows pinned in at a 90-degree angle and slowly move them forward until they are touching your thighs. Your palms should remain facing up throughout the exercise. Tighten your stomach muscles and squeeze your shoulder blades together as you lift the weight above your head. Don't lock your elbows at any point during the movement or you might risk having the weight crash into you. Once you've reached this position, hold it for two seconds then slowly return to the starting position.