You can get big pecs, biceps and triceps without purchasing a weight set or machines. You already have a large amount of weight at your disposal -- your body. Exercises that make your arm and chest muscles lift your body against gravity exercise these areas to build strength and bulk.
Pushups for Pecs
Pushups build muscle in the chest and arms. Difficult variations of the pushups also work the shoulders, glutes and abs. To build muscle, you want to lift heavy weights. One way to make your chest and arms lift more weight doing a pushup is to add a leg lift. To perform this variation, first assume pushup position with your arms straight and hands in line with your shoulders. Then, lower your chest toward the floor and simultaneously lift one leg toward the ceiling. On the next repetition, raise the other leg.
Inchworms for Arms and Abs
Inchworms are another body-weight exercise that works the chest and arms. Inchworms are an advanced, total-body exercise that also work your abs, shoulders and back muscles. To perform inchworms, start bent over with your fingers on the floor just in front of your toes. This is the starting position. Next, walk your hands forward and lower your body into pushup position. Do one pushup and then walk your feet forward to your hands as you come back to the starting position. With every rep, you move forward.
Chair Dips for Triceps
Chair dips are one of the best exercises for your triceps. Just make sure that you use a sturdy chair that won't tip, break or roll out from under you. To begin, sit in the chair and grip the edge of your seat, placing your feet together on the floor in front of you. Raise your buttocks off the chair holding your arms straight, and bring yourself forward just far enough so that you won't hit the seat when you lower into a dip. Align your knees with your ankles. This is the starting position. Bend your elbows next, lowering your hips below the edge of the seat, and then press your arms straight again. You should feel your triceps working when you lift yourself up.
Chinups for Biceps
Chinups do not require weights, but they do require a pullup bar. You can find one at the gym or likely a playground if you don't want to purchase one for your home. Chinups target the biceps and the back. To begin, hang from a bar with your knees bent and your palms facing you with your hands in line with your shoulders. Next, bend your elbows and pull yourself up to the bar. You should feel the biceps working to bring your chin up to the bar.