What makes the plank tough, though, is only partly that it keeps your core engaged. It also tires your mind. Frankly, it’s boring. You can’t increase the reps. To make it tougher, you need to add minutes. Long, slow minutes. But there is a move that makes the plank not only exciting but more dynamic, too.
The plank drag uses a weight that you pull from side to side, testing upper-body and core strength, balance, and endurance.
“Adding in the drag portion is amazing because it makes the position more active, says Gerren Liles, a New York City–based trainer. “Rather than employing a static hold, you’re learning how to engage your abs through the movement while getting a little resistance work in with the pull.”
The move is versatile: Use almost any weight that’s lying around. A weight plate like the one below works well, as does a dumbbell or a ViPR (that heavy, two-handled cylinder at the gym). You could probably do it with a sack of onions.
Match your pacing to the weight you’re pulling. Go slower for a heavier object, focusing on form. If the weight is light, move more quickly through the reps, which will get your heart rate up. Aim for 10 to 12 reps per set.
The drag is a tougher test of balance than a regular plank. Your body weight will want to shift with each pull, and as you get tired, your hips may start to rotate. Resist. Focus on remaining flat, and avoid pedaling through your feet. The key to this move, like its effective-but-dull forefather: Squeeze your glutes.
HOW TO DO IT:
1. Start in a high plank, balanced on your palms and balls of your feet, with the weight set to the left side of your body, just behind your palms.
2. Reach your right hand across your body to grasp the lip of the weight, then drag it until it’s under your right palm.
3. Return right palm to floor, grab weight with left hand, and pull left for one rep.
Source Link - https://www.mensjournal.com/health-fitness/how-do-plank-drag-workout-move/