To do it: Lie on your back with your knees bent, feet flat on the ground. Bring both arms overhead and hold onto the bottom of couch or a heavy medicine ball (as shown). Cross your right ankle on top of your left knee. Exhale and lift your legs in (in the same cross-legged position) as close to your chest as possible, lifting your hips and lower back off the floor. Inhale and slowly return to the starting position. That’s one rep. Try for up to 15 reps with the right leg, then repeat on the left.
Despite the fact that sit-ups been widely rebuked—everyone from Harvard Medical School to the U.S. Army advises against performing them—you shouldn’t discount the classic move just yet. The sit-up’s “primary function is to work your rectus abdominis, which are those six-pack muscles that most people want,” says Katie Barrett, lead instructor at B/SPOKE Cycling Studio in Boston and a certified personal trainer. “But doing that full sit-up is also going to work your hip flexors and other stabilizing core muscles.” The key is making sure you’re doing them correctly. (And here’s how to do just that).
When you're doing exercises to strengthen these muscles, think of the abs and core as one unit. Even when you do exercises that recruit more of one muscle than the others (for example, side planks that really fire up the obliques), you'll notice that you still have to engage your entire midsection to do them right, which is proof that these muscles are never working completely alone. It's important to show equal love to all of the muscles of the core so that this unit can power itself properly from all angles. 

Even though your rectus abdominus is the muscle you want to see when you look in the mirror, your inner core muscles, including your internal obliques and transverse abdominis, are the foundation for your six-pack. “You would not build a mansion on a weak foundation, so don’t try to build a six-pack on a weak core,” Cary says. This is when you’ll want to try out some more creative core workouts like planks, dead bugs, core twists, and farmer’s walks, he says. All of these tap your core’s ability to stabilize, rather than crunch, your core.
Start in a side plank with left forearm on floor, elbow under shoulder, feet stacked, and hips lifted so body forms one long, straight line. Stretch right arm up to ceiling. This is your starting position. Draw the right hand down and reach it below left underarm as you curl upper body forward so shoulders are parallel to floor. Return to starting position. Repeat for 30 seconds on each side.
For example, believing that you should eat your pre-workout meal is a great way to procrastinate with your training. What if you worked overtime and you don’t have enough time to eat your pre-workout meal? What if you don’t have enough money to buy supplements? All the items in the above list have the potential to evolve into excuses for procrastinating, or worse, quitting. Just forget about them and only do what matters. This will save you enormous time and willpower that should be spared for the things that actually matter in your quest to get abs.

I’ve had several friends ask me what I did and what they could do to get fit so I decided to nail down everything in this detailed article. I’ve also tried to bust a lot of ‘six pack myths’ in the process by backing them up with scientific explanations and relevant links wherever possible. Whether you’re fat, skinny or somewhere in the middle, I’m sure you’ll manage to takeaway something after reading this!
Start on the floor with your feet outstretched (more difficult) or your knees slightly bend with your heels on the floor (a bit easier). Contract your core, lift your upper body from the hips so your lower back and shoulders are about 10 inches off the floor. Stretch your arms out along your sides with palms up, and simply hold that position for up to a minute at a time. Ouch. It's a good one.
This athletic move takes the plank to an all-new level. "It not only improves your core stability, but it targets muscles in your hips, groin, lower back, and often-neglected lower abs," says Durkin. Get your heart pumping by speeding up the movement, or hammer your core muscles by slowing it down. Either way, the exercise will boost your athleticism and will give you something to bare at the beach.
A University of Southern Maine study found that a single set of a weight-training exercise torches as many calories as running at a 6-minute-mile pace for the same amount of time. So for every second you spend lifting weights, your body is expending high amounts of energy. Add high intensity interval training (HIIT) principles to your workout, and you could see even more gains.
“I alternate between all-out effort sprints (30 to 60 seconds) and walk/jog as a recovery until I feel fatigued. Intensity is key. Abs work as stabilizing muscles during a sprint, so the harder I push myself the harder my abs will work! Plus, there’s no equipment required, and I get a high calorie burn and full-body workout done in very little time. (I tell myself I can do anything for 30 seconds.) Depending on how I feel, I’ll either add this to the end of a routine or make it my entire workout, two to three times a week.” —Suzanne Cover, @suzannecover
The recipe for six-pack abs isn’t all that complicated: Crank out an abs workout, eat a nutrient-rich diet, and consume fewer late-night pizzas in a single sitting. The undisputed holy grail of men’s fitness is good for more than just an extra boost of confidence whenever you have cause to peel off your shirt, too. “The best way to avoid injury, whether in the gym, at home, or at the workplace, is by building a strong core,” says Edwin Wealth, NASM-CPT and trainer at Equinox. Want to do yoga better? Run faster? Squat heavier? Carry the groceries without wincing? It all begins with your core.

Try starting your day off eating heavier, and ending on a light dinner. Instead of waking up and running out of the door with a banana, eating a small lunch, and then eating a hefty dinner, try making your breakfast your heaviest meal and your dinner the lightest. For carb intake at dinner time, try to ingest the wet types of carbs that are in high-water, medium-fiber foods.

To lose weight, he should consume 1800 calories per day and stick to the regular work out routine. On the other hand, women must consume 10% less calories than men in order to lose weight. For instance, a woman who wants to stick to her actual weight should consume between 1800 and 2250 calories, and if she wants to lose weight, she should consume between 1600 and 2000 calories per day.

Bent-Elbow Plank: This exercise works the whole trunk, particularly the transversus abdominis. Start by lying on your belly and then lift yourself up onto your toes and forearms (elbows in line with shoulders) while contracting your abdominals and keeping your back neutral. Hold that position for five seconds, then rest and repeat. Ultimately, strive to hold the pose for 90 seconds without any rest -- for one set. If you're more experienced, you can also do this exercise on your hands and toes. (As a beginner, start on your hands and knees with a neutral spine and simply contract the abdominals on an exhale without moving your back.)
How to: Lie on your left side with your legs straight and your right leg stacked on your left. Position yourself so your weight is resting on your left forearm and the outside edge of your left foot. Your elbow should be directly beneath your shoulder, and your upper arm should be perpendicular to the floor. Align your body so it forms a straight line from your neck to your ankles, and place your right hand on your hip. Lower your hips toward the ground a couple inches, then come back up to start. That’s one rep. Do 15 reps on each side.