You don't need an exercise machine to develop rock-hard abs.
Building your abs and pecs isn't just about changing your appearance. When you boost the mass of these two muscle groups, you dramatically increase your ability to perform all manners of daily tasks with ease, and if you play sports, it's also possible to notice improved performance. You don't need access to a weight machine to develop these areas; body-weight exercises can provide more than enough of a challenge.
Abs and Pecs Are Tempting to Build
Many people seek to develop their abs and pecs because of the location of these muscles. Provided you don't carry excess body fat, it's possible to make your abs and pecs stand out. Technically known as your rectus abdominis muscles, your abs are situated on the front side of your lower torso and contribute to the movement of your spine. Your pecs, meanwhile, are called your pectoralis major muscles and make up your chest. These muscles help you move your shoulders.
Bicycle Toward Stronger Abs
According to the American Council on Exercise (ACE), the bicycle maneuver exercise results in the most rectus abdominis activity. This exercise, also known as the bicycle crunch, doesn't require any equipment. Perform this exercise in a similar manner to traditional crunches -- lie on your back with your knees bent and your hands to the rear of your head. Keeping your legs bent at 90 degrees, elevate them so your lower legs are parallel to the floor. In a steady rhythm, bring your left knee toward your right elbow and then back down and vice versa.
Press Your Way to Strong Pecs
The best way to strengthen your pecs, according to the ACE, doesn't require a machine. The organization notes that the barbell bench press, which you perform with a barbell rather than a weight machine, generates more muscle activity in your pecs than any other chest exercise. Perform the barbell bench press by setting a barbell of your desired weight on the rack and lying beneath it with your legs bent, your feet on the floor and your back flat on the bench. Grab the bar with an overhand grip that's wider than your shoulders, lift the weight away from its rack and bend your arms to lower the bar toward your chest. Push the bar away from your chest until your arms are straight and continue this pattern.
Correct Form, Low Reps
Including the bicycle maneuver and barbell bench press in your regular strength-training workout can drastically improve the strength and overall health of the target muscles. The American College of Sports Medicine (ACSM) advises performing these exercises in sets of between eight and 12 repetitions. Although the ACSM notes that one set per exercise is acceptable, you can consider including a second set, provided you can continue to execute each rep with the correct form. Aim to allow one to two days for recovery between workouts.