There’s more to developing the type of six-pack abs stars like Tim McGraw and Riley Green have become as famous for as their music. While many gymgoers would gladly accept a nicely defined core, putting in the work in the gym as well as the kitchen is a different story. Knocking out a few sets of crunches or following the latest eight-minute abs gimmick may feel like work, but it’s probably not the kind of work your core needs to make any noticeable aesthetic gains.
At the same time, a solid abs workout doesn’t require marathon sessions, as Dan Fahey—better known to his nearly 400,000 YouTube subscribers as Gritty Soldier—shows in a recent training clip. The U.S. Army instructor built this 15-move, 15-minute core circuit for one purpose: to keep your abs under constant tension while forcing you to hold rock-solid form under fatigue.
Fahey’s training philosophy is simple and shared by many fitness experts: a strong core makes everything stronger—lifting, running, rucking, and daily life. Short, focused sessions done with discipline often beat marathon ab routines done sloppy. This workout hits your entire midsection—rectus abdominis, obliques, deep stabilizers, and glutes—while drilling mental toughness every round.
For this workout, you’ll go 40 seconds on, 20 seconds off for each move. By the end, your core is smoked—but take comfort in knowing your abs, not your ego, did the heavy lifting.
What a 15-Minute Bodyweight Core Session Can Do for You
This calisthenics-style routine isn’t a magic six-pack button. It’s a practical, efficient way to:
- Strengthen your abs, obliques, and deep core muscles
- Improve posture and spinal stability
- Build muscular endurance so your core can handle harder training
- Burn extra calories and elevate your heart rate
And the best part? If you somehow make it through this grueling core challenge and still have gas in the tank, you can rewind the video and run it again.
The 15-Move Core Circuit
- Dead Bug: Keep your lower back pressed into the floor. If it arches, you’ve lost the core.
- Bear Plank Hold: Keep your knees just a few inches off the ground, back flat, eyes slightly forward—don’t let your hips creep up.
- Glute Bridge March: Squeeze your glutes and drive hips straight up before you march. Don’t let your hips drop as you alternate legs.
- Bird Dog: Move slow and controlled. Reach long through heel and fingertips, like you’re trying to stretch the room.
- Forearm Plank: Think “straight line from head to heels.” No sagging, no piking—brace your abs like you’re taking a punch.
- Bicycle Crunches: Twist from the ribcage, not the neck. Slow them down to actually feel the obliques work.
- Flutter Kicks: Wide, slow kicks just off the floor. Small and fast is easier—wide and controlled is where the burn lives.
- Heel Taps: Keep your upper back off the mat and reach side‑to‑side. The crunch toward the heel matters more than actually touching it.
- Hand Release Pushups: At the bottom, fully release your hands, reset your tension, then drive up as one solid plank.
- Hollow Hold: Start with legs higher if it’s too hard. Maintain that “banana” shape and never let your lower back leave the floor.
- High Plank Shoulder Taps: Widen your feet and fight the sway. Your hips should stay quiet while your hand travels.
- Reverse Crunches: Think about curling your hips toward your ribcage, not just swinging your legs.
- Side Plank (Left): Stack your feet, lift the hips, and keep your body in a straight line—no collapsing at the waist.
- Side Plank (Right): Same focus: long line from shoulders to ankles, eyes forward, breathing steady.
- Plank Hold (Forearm): This is the mental test. Lock in your form, squeeze everything, and ride out the final 40 seconds.
You can check out more of Gritty Soldier’s workouts on his YouTube Channel or by downloading his training app.