Forget sit-ups — it only takes 15 minutes and 1 dumbbell to build a strong core
When you purchase through links on our site, we may earn an affiliate commission.Heres how it works. While sit-ups and crunches are great for building strength and stability in your core, they arent essential. What is the workout? Depending on your ability, youll repeat the circuit two or three times through. Youll need one of thebest adjustable dumbbellsto complete this workout. Then take 20 seconds rest before moving on to the next exercise....