The core muscles are really important for the human body to move and operate well. Just about every functional movement you can think of uses abdominal muscles to a degree.

Whether lifting, throwing, pushing, running, or jumping, many popular sports include moves that depend heavily on strong abs. Being centrally located, the core muscles stabilize your body while still or in motion. Well-trained abs make for good balance and a better overall physique.

Before starting your core workout, it helps to understand the muscles that make up this part of the body. In addition to the frontal abdominal muscles (typically known as a six-pack), you have the external oblique muscles on either side.

Both of these muscle groups can become visible with enough training. The external obliques sit on top of the internal obliques. The deepest core muscle is the transverse abdominal. This thin layer of muscle is responsible for stabilizing the whole core and lower back.

The following exercises are simple yet very effective at working your abs. They don't require any equipment (except for maybe a mat) and are varied, so you will rarely get bored of them. You can fit these exercises in when you have a spare 10 minutes or do them as part of a wider fitness plan. As a bonus, this intense routine is also a decent cardio workout.

This core workout definitely beats staying in the painfully boring plank position or struggling through countless sit-ups. Let's take a look at some of these techniques.

Crunches

This is probably a familiar exercise to most people. To start, lie flat on a mat or bed with your hands behind your ears. Lift your legs several inches off the surface. Next, in one motion, raise your shoulder blades and torso by around 30°, then pull your legs in towards you. Once you contract, your knees and elbows should almost meet.

You should avoid pulling your head/neck by letting your abs do the work. Now you can release by lowering your legs and shoulders. Your legs should remain raised for the entire set of crunches.

High Knees

This exercise is typically thought of as a warm-up before a jog. Yet this can easily kill your core with the correct form. While standing up straight, begin to raise one knee as high as it can reasonably go. Then switch knees. Alternate and build up a rhythm so that you are almost jogging on the spot.

By maintaining good posture in your back, you will work your lower abdominals very hard. Jump from the balls of your feet to stay balanced. You will notice your heart and breathing rates spike, as this is quite intense cardio and an excellent core workout.

Mountain Climbers

Continuing with the cardio theme, here is another method to work your core and heart simultaneously. Go into a high plank position―that is the same starting position as a push-up. Straighten your whole body, and touch the floor with your toes pointed and hands flat.

When ready, take one foot off the ground and bring your leg up until your knee almost touches your chest. Bring your leg down and do the same with the other. Now alternate and build a rhythm as with high knees.

Windshield Wipers

This impressive movement will build rotational strength in your core by exercising your oblique muscle groups. Lie flat and place your arms horizontally. Your hands should face down to give you leverage for pushing. Lift your legs towards the sky and begin to rotate them side-to-side.

Try to move your legs close to the ground without hurting your back―range of motion depends on your flexibility. Also, avoid lifting your back off the ground.

Oblique Crunches

As an extension to regular crunches, try this oblique variation. As the name suggests, this will also target your oblique core. As before, raise your legs off the floor and lift your shoulders by about 30°. Now contract your abs and bring one leg towards your body. While you do this, turn your shoulders the opposite way so that your right elbow is close to your left knee.

Reverse the motion, then do the same on the other side. Keep going to build up a cyclic rhythm, and do not let your legs rest until the end of the set.

Reverse Crunches

While lying on your back, place your arms by your side with your hands facing down. Lift and bend both legs so that they form a right-angle (as shown at the top). Tense your core muscles to pull your knees towards your chest while pushing with your hands. You will naturally roll onto your shoulder blades.

When you have fully contracted, uncurl and return your legs to the first position. Continue with more repetitions, remembering to press firmly with your hands and to keep your core tight.

Bridges

With your back flat and arms beside you, bend your knees while keeping your feet flat on the ground. Your knees should be pointing upwards. Push downwards with your feet to arch your body from the shoulders. Try to keep your back straight and grip with your hands to prevent sliding.

Continue with this motion for the whole set. This core workout is fantastic because it also trains your glutes.

Isometric Pose

This final exercise is different from the last 7 because it is completely static. Lie fully flat with your arms at your sides. In one step, lift your legs and shoulders off the ground to form a V-shape with your body. Your abs should work to hold this position so that only your lower back touches the floor. You do not need to hold the legs and shoulders very high.

Try to maintain this pose for the duration of your set. This core workout is also unique compared to the others since it works the transverse abdominal thoroughly. This will improve your balance.

Core Workout: Summary

Feel free to build a routine with the combination of movements that suits you. It is best to perform each exercise for between 30 and 60 seconds (or a sensible number of repetitions). Take a short break and then progress to the next move. In total, the workout can take less than 10 minutes. It can go on for up to 15 minutes, but not much longer. With core muscles, it is much better to work them intensely and regularly.

Practical reasons aside, building strong core muscles will help you to lose stomach fat and look slimmer. Not everyone can or wants to be a world-class bodybuilder, but having well-defined abs is key to a better, stronger-looking figure. Plus, the exercises shown above are simple and fast; you don't need to spend hours for an extremely tough core workout.

With these techniques, it is crucial to take care of your neck and spine. Some pain near the stomach is expected, but never hesitate to take a rest day and let the abs heal. Stay hydrated, and do not push yourself if something hurts a lot.