Forget sit-ups — 3 seated ab exercises that build your core muscles using one dumbbell

a woman doing a side crunch with her abs on show
(Image credit: Getty Images)

Finding ways to be creative with a dumbbell might not be your idea of a good time, so we’ve done the hard work for you — here are three muscle-torching seated ab exercises that strengthen your core and upper body.

Thankfully, some of the best ab exercises can be done sitting down, supporting the lower back and benefitting anyone with limited mobility. You just need one of the best adjustable dumbbells and your exercise mat to do them, which means the moves are accessible for most people. 

You can add these core exercises to your existing routine, or if you need some help programming, check out the three-move seated ab workout we’ve designed below. 

What are the three seated ab exercises?

If you’re a beginner to weightlifting, use a light weight and focus on keeping good form; progressively add weight as you build strength and brace your stomach as you perform each exercise. To hit as many core muscles as possible, we’ve included seated ab exercises that target the abs, obliques and deeper core muscles responsible for stabilization. 

You’ll perform exercises in different planes of motion, including torso extension and flexion to target the abs and rotational movement to help hit the obliques. Best of all, you won’t need to lay down or stand. 

Seated dumbbell V-tucks

Man in home performing knee tucks with hands by his sides and knees bent in the air

(Image credit: Shutterstock)

Strengthening your core muscles with weights can improve the functioning of your torso, including posture, spine health, coordination and balance. V-tucks are a variation of crunches designed to torch your abs, hip flexors and obliques and improve trunk balance. 

You can do tucks on an exercise mat, box, or chair. Place your hands down for support or behind your head for an extra challenge. Bend your knees and lift them away from the floor, slightly lean back, keeping a flat back, and extend your legs away, then draw your chest and knees together. Keep your chest proud and shoulders relaxed as you move. Once you can perform 10 reps without your hands, hold a dumbbell in front of your chest.


Man outside on the beach performing an L-sit using two bars

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Learning how to hold the L-sit elevates any core workout using isometric contraction, meaning without your muscles moving. Sit on your bum with both hands on an elevated surface like dumbbells, chairs, or boxes. Push through your hands and extend your legs in front of you, then lift both legs off the ground and hold the position. The idea is to create an L-shape with your body, but if that’s too much too soon, try tucking your knees toward your chest. 

It’s a demanding exercise for your core and hip flexors and helps develop posture and flexibility.

Seated dumbbell twists

an illustrated photo of a woman doing a dumbbell Russian twist

(Image credit: Getty Images)

Similar to dumbbell Russian twists, seated twists engage your obliques, and this variation will also work your arms and shoulders. Sit on your exercise mat, a chair, or similar and lengthen your spine to ensure a tall posture. Hold a dumbbell with both hands and extend your arms away from you in front of your chest. Twist slowly to your left, pause, then return to the center and repeat on your right. Maintain a tight torso and ensure you only rotate your upper body, not your hips or legs. 

3-move dumbbell seated ab workout to try

Once you’re familiar with the dumbbell exercises above, try this muscle-torching AMRAP pyramid workout. 

10 minutes:

  • Seated dumbbell V-tucks x 8 reps
  • Seated dumbbell twists x 8 reps
  • V-sit x maximum hold

Start with 8 reps of the V-tucks and twists, then move to a maximum V-sit hold. On the next round, increase your reps by 2, and continue to achieve a maximum L-sit hold each round. Complete as many rounds as possible in 10 minutes. Reps are guidelines only, so increase or decrease as necessary.

There’s plenty to love about a pyramid workout, which builds slow intensity in a short time to overload the muscles. In this instance, you’ll slowly increase reps to a time limit, but you could also set a high number of reps and race against the clock to decrease your reps to 0. 

However you approach it, you shouldn’t feel these exercises in your back. Always practice with your body weight first if you haven’t tried the exercises before, and if you’re unsure, pass it over to a personal trainer for advice on whether or not these ab exercises are for you. 

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Sam Hopes
Senior Staff Writer - Fitness

Sam Hopes is a level III fitness trainer, level II reiki practitioner, and senior fitness writer at Future PLC, the publisher of Tom's Guide. She is also about to undertake her Yoga For Athletes training course. Having trained to work with mind and body, Sam is a big advocate of using mindfulness techniques in sport and fitness, and their impact on performance. She’s also passionate about the fundamentals of training and building sustainable training methods.  When she's not writing up her experiences with the latest fitness tech and workouts, you’ll find her writing about nutrition, sleep, recovery, and wellness.