Abdominal crunches are a single joint exercise, which means only one joint is used to perform the movement -- in this case, the hip joint, says the FITDAY website. This type of exercise is also called an isolation exercise because it targets a single muscle group, in this case, your abs.
Benefits
Single joint exercises like crunches are handy if you need to strengthen a particular part of your body, for example, after an injury or surgery, or if you haven't used that particular muscle group in a while, says FITDAY. In the case of crunches, you are isolating your abdominals, which means other muscles can't help do the work and make it easier on your abs.
Disadvantages
Because you are only working one joint and muscle group, you don't burn as many calories as you would when doing multi joint exercises, says FITDAY. As the name suggests, multi joint exercises, such as pushups and squats, require you to use lots of different joints and muscles. Another downside to single joint exercises is they don't train your muscles to function alongside other muscles, as they need to in order to perform everyday activities, says fitness expert Vic Magary on the Gym Junkies website. While there's no harm in doing single joint exercises, they should be done in combination with multi joint activities to ensure you get optimum results and functionality from your muscles. There are plenty of multi joint alternatives to the crunch for strengthening your abs.
Knee Pull-up
You will need a fixed bar for this exercise, which focuses on your abs, but also works your biceps and your back muscles, says BodyBuilding.com. Movement occurs in your knee, hip and elbow joints, so it definitely qualifies as a multi joint ab exercise. Take hold of the bar with your hands about shoulder-width apart, your palms facing toward you and your arms straight. Bend your knees back to 90 degrees. Then, as you bend your arms to lift yourself up, bring your knees forward and up to your chest. Slowly lower back to the start position and repeat.
Bicycle Crunches
You don't need any equipment for this exercise, which targets your rectus abdominus muscles down the front of your stomach, as well as your obliques, which run down your sides, says the fitsugar website. Lie on your back on the floor and place your hands behind your head, elbows pointing out to your sides. Raise your shoulders off the floor and bring your knees in to your chest. Then straighten your right leg and twist your right elbow toward your left knee. Bring your right leg in and straighten your left leg, this time twisting your left elbow to your right knee. Make sure you twist your rib cage, not just your elbow, and keep your legs off the floor when in the straightened position. Keep the movements slow and controlled to ensure your muscles, rather than momentum, do the work.
Member Comments