Simple yet more efficient than sit-ups/ crunches, leg raises can build abs and also the core strength.
Sit-ups and crunches aren’t giving you the abs that you hoped? Well, they won't. At best, you'll have a four-pack. Because they don't do anything for your lower abs, which are a tricky proposition, to work them, just raise your legs! Include them in your daily grind or even on their own, with a potential to give you the full six, why settle for else?
Easy At First
If it's easy, it isn't true. Perhaps, but not this. Do 30sec-hold, no-stop, ten reps - you'll know when the savagery kicks in.
How to do them?
Lie straight on a mat face-up, hands touching the sides. Raise both your legs, breaking them below the lower abdomen with toes pointing at the ceiling, spine flat on the floor and your hips lifting slightly off it. Harness your core strength and not momentum to achieve the lifts. Take a deep breath while lifting and hold it when fully up, initially for 10-15 seconds, which you can then extend to 30 or longer, and slowly breath out, returning back to the starting position. To derive the best out of this movement, be slow and in control. Pace the manoeuvre equally going up and coming down.
After getting the hang of it, try this: while bringing the legs down, instead of grounding, let the legs hover inches above it and take it up again. Target three sets of ten or as many you want/can.
Lift-Off Hacks
This three tips can help the beginning struggles: stabilize your posture by leveraging your palms below the bum but don't let that spine curve up; bend the knees briefly to move up but straighten them before the holding position; lift one leg to follow the other - you can even try with one leg a time, alternating evenly between them to get into a groove.
Some Variations
Grip a medicine ball between your feet - additionally shapes hips and adductor muscles.
Attach equal and reasonable weights (not dumbells) circling the ankles.
Do the leg-raises in a dip station.
Hang from a pull-up bar, raise the legs to be parallel to the ground, toes pointing at the facing wall.
Curl up your legs and raise the thighs to be parallel to the floor, knees pointing out straight.
Want to strain a bit more: bring your knees to your chest and back to the above.
Additional Benefits
Apart from its intended purpose, the leg raises also improves hip and lower back flexibility.
