To do it: Lie on your stomach with your upper body propped up on your elbows and a dumbbell upright on the floor about six inches in front of your chest. Tuck your toes under and lift your body into a full elbow plank, making a straight line from your head to your heels, drawing in your abdominals. To start the move, lift your right arm off the floor and use your best freestyle stroke to reach over and past the dumbbell—as far as you can—allowing your hips to rotate into the stroke and turning through the balls of your feet. Finish the full stroke before returning to elbow plank position. Repeat with the left arm. That's one rep. Do 10 reps total, alternating sides each time.
Contrary to what popular culture portrays, one does not need to lift really heavy if muscle hypertrophy, aka “bigger muscles” or aesthetic gains are the primary goal (see bodybuilding vs powerlifting). One needs to ensure that a particular muscle is subjected to enough time under tension and training volume to ensure that muscle fibres are broken down and rebuilt stronger over time. This can be done by following a high-volume, moderately high rep range, moderate weight and low rest period lifting routine. I start off with 5 sets of a heavier compound lift eventually moving to isolation exercises. I started off with the popular ‘3 sets of 10’ for isolation exercises, then to 12 and now hit 4 sets with the rep ranges 15,12,10 and 8. Higher reps would mean a lighter weight and vice versa. My last set is almost invariably a dropset. I hit around 15 -18 working sets per muscle group per week.
AthleanX — If I were to recommend you ONE channel, this would be it. Don’t watch anything else, just listen to Jeff Cavaliere. His entire approach towards fitness is something that has come to resonate with me. There’s no bulking-cutting nonsense, pure focus on form, getting the maximum out of each exercise and a lifelong approach towards good, sustainable nutrition. If I wanted a few exercises to target a particular muscle group, this is where I go to first, learn them, try them out in the gym and invariably get results. There’s a ton I’ve learnt from Jeff and couldn’t thank him enough.
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.
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 do it: Stand with your feet planted 3-4 feet apart, toes slightly turned out, hands on your hips. Lower into a plie by bending your knees out over your toes and lowering your hips directly underneath your shoulders. Then, as your straighten back up, slowly lift the right knee up towards the right shoulder. As you go back into the plie, slowly return the foot to the floor. Be sure to move at a very controlled pace to really engage the obliques the entire time—on the way up and on the way down. Do 10 repetitions on the right side, then another 10 repetitions on the left side for a total of 20.

best ways to build core