SKIP THE SIT-UPS

Idea

Sit-ups were once ruled as the way to tighter abs and a slimmer waistline, while “planks” were merely flooring.

Now planks exercises in which you assume a position and hold it — are the gold standard for working your core, while classic sit-ups and crunches have fallen out of favor. Why the shift?

One reason is that sit-ups are hard on your back — by pushing your curved spine against the floor and by working your hip flexors, the muscles that run from the thighs to the lumbar vertebrae in the lower back. When hip flexors are too strong or too tight, they tug on the lower spine, which can be a source of lower back discomfort.

Second, planks recruit a better balance of muscles on the front, sides, and back of the body during exercise than sit-ups, which target just a few muscles. Remember, your core goes far beyond your abdominal muscles.

Finally, activities of daily living, as well as sports and recreational activities, call on your muscles to work together, not in isolation. Sit-ups or crunches strengthen just a few muscle groups. Through dynamic patterns of movement, a good core workout helps strengthen the entire set of core muscles the muscles you rely on for daily activities as well as sports and recreational activities.

You needn’t spend a cent on fancy equipment to get a good workout. A standing core workout and floor core workout rely on body weight alone. With the help of some simple equipment, you can diversify and ramp up your workouts. To start, consider buying only what you need for the specific workout you’d like to do. If you have a gym membership, use the facility’s equipment. Here is a description of all of the equipment used in the six workouts designed by Harvard experts and found in our report Core Exercises.

Chair. Choose a sturdy chair that won’t tip over easily. A plain wooden dining chair without arms or heavy padding works well.

Mat. Use a nonslip, well-padded mat. Yoga mats are readily available. A thick carpet or towels will do in a pinch.

Yoga strap. This is a non-elastic cotton or nylon strap of six feet or longer that helps you position your body properly during certain stretches, or while doing the easier variation of a stretch. Choose a strap with a D-ring or buckle fastener on one end. This allows you to put a loop around a foot or leg and then grasp the other end of the strap.

Medicine ball. Similar in size to a soccer ball or basketball, medicine balls come in different weights. Some have a handle on top. A 4-pound to 6-pound medicine ball is a good start for most people.

Bosu. A Bosu Balance Trainer is essentially half a stability ball mounted on a heavy rubber platform that holds the ball firmly in place.

www.health.harvard.edu