All of us are so obsessed with our abs that we often end confusing our core with core. But when your trainer talks to about your core it is actually not just about strengthening your abs but it also includes your glutes, hips and lower back.
In order to prevent some injuries it is highly important to keep your core strong. If training your core, it helps to improve your posture, reduce your back aches and improves balance. Look further in order to find some of best core training exercises in three different levels to work on your core:
Core Training – Level 1
while in this level, you need to do three simple exercises, that may be
considered as beginner level exercises and you just need to 5 to 7
minutes daily to do these exercises.
Skyscrapers – 10 Reps Each Side

In order to do this kind of exercise, you should start with a straight
arm plank position and turn your body in inside of plank with your left
palm on the floor. Stretch out the right hand towards ceiling, while
forming alphabet T and hold this position for 5 seconds. Rotate back, in
order to start arm plank and follow ten reps and repeat on the other
side.
Windshield Exercise – 10 Reps Each Side

In order to do the windshield wipers exercise, you should lie on your
back on the floor and raise your legs to form ninety degree angle. So
stretch your arms on either side and rotate your legs from one side,
and then stop short of touching floor and rotate to other side. Have ten
reps on each side.
Army Scrawls – 36 Steps

This kind of exercise is very much similar to how commandos crawl on
their elbows and elbows and to do this exercise start in forearm plank
position and begin to go forward with your arms and drag your legs.
Follow these crawls to the count of 36.
Core Training – Level 2
While doing this level you will need to follow four exercises, which
once again will take about 5 to 7 minutes. In order to increase the
challenge, follow these exercises twice a day.
Break-Dancer – 15 Reps Each side

Start off with the normal plank position, while your body is straight
and arms are straightened for support. You should make sure your feet
are hip width apart. Slide the left foot under your right leg, while
rotating your body and raising keeping your hips eight inches above the
ground level. Then return back to starting position and follow the same
on the opposite direction.
Sky-Diver- 30 Seconds Hold

For this one, you shall lie down on your stomach and bend your knees and
elbows, then lift your head, the chest and arms and knees off the floor
same as you are skydiving and hold the position for 30 seconds. Make 10
reps.
Dead Bugs – 10 Reps

For this dead bugs exercise, you need to lie on your back with your arms
extended in front of your shoulder and bring your buttocks and knees to
90 degrees, and tighten your abs and keep your lower back pressed on
floor. Breath deeply and as you exhale, extend the left leg towards the
floor and right arm overhead. Return again back to starting position
and make ten reps with alternate legs and arms movements.
Thread Needle – Ten Reps Each Side

Start off with the straight arm plank position and turn your body on to
either side of your body to form a side plank. And then move your arm
under your torso as far as you can and move your head the same direction
as well. Hold in this position for five seconds and return to starting
position. Make 10 reps each side.
Core Training – Level 3
This core training consists of some difficult exercise. Follow the
exercises that follow only after you feel your body is comfortable with
the exercises from the 2nd level.
Crab Kick In Superman – six per side

This kind of exercise is quite complicated to understand in the
beginning. So to do this exercise get into a crab position and raise
your left hand and right toe. Bring left hand to touch your right toe.
Turn the body on the other side and then raise you left arm and right
leg to form a superman position. After that , return back to crab
position. Follow 6 reps on each side.
Star leg – 10 reps each side
For this one, you shall get your body on side plank position and then
raise your left arm to face the ceiling. In a slow way lift your left
leg to form a star position. Return to your starting position, and then
follow ten reps on each side.
Slide V- Ups -10 reps each side

For this one, lie on your left side in 30 degree angle. Place your right
on the floor and raise your legs up to a side. In a simultaneous way
raise your left arm to touch your toes. Make 10 reps of this exercise on
each side.
Over And Under Plank Exercise
This one is quite a tricky exercise and will require a lot of practice.
Get up to normal plank position and bend in your right leg and bring
your leg under abs. Now, you shall bring your left arm under your abs
and try to touch your toes. Once that you have tried the under level,
you shall raise your leg over your back and touch your toes.