You don't really want to do a hundredth sit-up, do you? They're one of those exercises you can do for ages -- often without dramatic results.
In fact, experts tend to agree that crunches and sit-ups are not only not the fast-track to washboard abs, they may even hurt the neck and back. And let's not forget that it's impossible to reduce body fat in specific spots; you can have the strongest ab muscles in the world, and they can still be difficult to see if they're surrounded by a layer of belly fat (sorry).
But your abs are important for reasons that stretch far beyond how they look at the beach: The stronger and more stable your midsection is, the more efficiently you can move your arms and legs. Strong core muscles also help you maintain good posture and balance, all while warding off low back pain.
There may not be one foolproof route to a stronger middle (20 different trainers all told Shape magazine a different favorite ab exercise, after all), but the plank is a solid place to start.
The Forearm Plank
- With your weight on your forearms and toes, lift yourself off the ground. (A plank with the arms fully extended, sometimes called a full plank, works too. Just know arm and shoulder muscles will take away some of the work from the core.)
- If this is your first plank, hold your body level for 10 seconds. If you've planked previously, aim for 30 seconds to a minute. (Or, if you're this young lady, an hour.)
- Maintain a straight line from your hips to your head -- your head shouldn't droop, your shoulders shouldn't lift or hunch and your hips certainly shouldn't sag.
Once you've mastered the forearm plank, it's time to mix things up. There are countless plank variations, but here are a few options to get you started.
Plank With Leg Lift
Lift one leg three to six inches off the ground with the foot flexed and hold for a few seconds, keeping the hips parallel to the floor. Lower and switch to the other side. Alternate sides until 30 seconds have passed -- and work up to holding for a full minute. Throwing your body out of balance like this ups the challenge, and that leg lift gets your glutes involved, too.
Side Plank With Hip Drop
Even the basic side plank will target the core muscles on the side of your body, the obliques and the transverse abdominis, but adding a slight drop in the hips requires them to work harder. Remember to only lift the hips back to the starting position.
Up Down Plank
This variation combines the forearm plank and the full plank. Starting with the right arm, "walk" from your forearm plank up to your full plank and back down again. Complete this cycle five times, then do five more leading with the left arm. Focus on limiting sidewise motion while keeping the hips parallel to the ground.
Plank With Knee To Elbow
The goal of this variation, also called the Spiderman plank, is to bring the knee as close to the elbow as possible. Focus on keeping your hips level as you alternate legs for 30 seconds. To ease off a bit, start in full plank position, which will give you more room to move your legs. Or to make it even more challenging, in full plank position, bring that knee to the opposite elbow.
Photos by Damon Dahlen for The Huffington Post