The women who could do the fewest number of sit-ups in 60 seconds had a significantly higher risk of dying. “Skeletal muscle may be a major storage site for glucose, and high (abdominal) muscularity may protect against diseases related to insulin resistance,” says Peter Katzmarzyk, Ph.D., an associate professor in the school of Physical and Health Education at Queen’s University in Kingston, Ontario. These include diabetes and heart disease.
So how do you do an ab crunch properly?
Find a place with a solid support but with a bit of cushion for your back. Grassy ground works well. If you must lie on a concrete or tiled floor, at least lie on an exercise mat to avoid straining your back. Note: women have more curvature in the lower back than men do, so provide extra back support when doing crunches. A rolled towel placed under the highest arch of the spine will work; find the best thickness that’s comfortable.
Your knees should be bent, your feet positioned as wide as your hips and both should be flat on the floor.
Your hands should be behind your head. Do not lace your fingers together; instead, your thumb should be positioned behind your ears and your other fingers should just be touching somewhere behind the middle of your head. Your elbows should be to the sides but not stiffly sticking straight out, just slightly rounded in, and level with your ears. Do not let them get close together.
Hold your chin forward, not tucked into your chest. You may feel that you achieve more by having your chin close to your chest, but you actually are not; it doesn’t improve your workout and only increases the risk of an injury. So try to look at the ceiling while doing crunches to ensure that your chin is in the right, safe position.
Exhale, contract your ab muscles, then curl up and forward. Don’t yank yourself up, but use your ab muscles to lift your head, neck and shoulder blades off the floor. Do not pull your head up with your hands. You’ll know if you’re doing this because you will feel the pressure behind your head and your chin will touch your chest. This means you are not using the ab muscles for the exercise and wasting your effort.
Pause for a moment, squeezing your abdominals as you do so. Then inhale slowly and ease your back down to starting position. Do not release and let go rapidly, plopping your back down. Controlling the movement while lifting your back up and going back down works your ab muscles both ways.
Relax your muscles for a moment, exhale and repeat. Throughout the exercise, be mindful to keep your knees bent and your feet in the same position. Never lift your lower back off the floor.
Crunches are best done very slowly, and always with control. When starting, you can do 12 reps at first until you can complete 3 sets at a time, then shoot for 20 reps per set. As you improve, increase the number of reps per set. If you do this faithfully 4 times a week, you will start to see results in as little as 2 months.
Aerobic Rebounding Provide Real Cardio Benefits
Jumping on a mini trampoline may provide real Cardio benefits. In a new study, 10 trained men and women, ages 24-28, rebounded for 10 minutes, rested 10 minutes, then jogged on a treadmill for 10 minutes at the same perceived exertion level. Their heart rate and maximum oxygen consumption were similar during both activities, equivalent to working out at 81 percent of their max heart rate.
“Rebounding can provide a scientifically sound workout for cardiovascular improvement and weight management,” says Len Kravitz, Ph.D., coordinator of exercise science at the University of New Mexico in Albuquerque. Because it’s low-impact, it may be especially suitable for people who want to avoid overuse injuries associated with jogging.