Getting great abs involves working your whole core. Orlando-based personal trainer Nick Parker calls the plank “one of the best” exercises for bikini season because it targets and pulls in the transverse abdominis, a deep stomach muscle that stabilizes your core. Exercise physiologist Tom Holland agrees; in a 2013 interview with “Men’s Fitness” magazine, he described the plank as one of the only exercises that works the entire core, including abs, lower back and obliques. For a quick but effective 10-minute plank workout, perform one 60-second set of static plank pose, 10 reps (on each side) of Spiderman plank raises, one 60-second set of mountain climbers, 10 reps (on each side) of twisting planks and one 60-second set of plank jacks. Then repeat the circuit one more time.

Plain old abdominal crunches don’t burn many calories and aren’t very effective for spot toning, but dynamic crunch variations can raise your heart rate and give core muscles more of a challenge. Holland is a fan of the bicycle crunch in particular because it combines a traditional crunch, an oblique twist and a reverse crunch. For a 10-minute crunch workout that will tone obliques and abs, do a 60-second set of bicycle crunches (hold each crunch for a count of two), 16 to 20 reps (on each side) of standing knee crunches, a 60-second set of cross crunches on the floor, 20 reps of standing pike crunches and 20 to 25 reps of toe tap crunches on the floor. Repeat the circuit one more time.

In 2001, the American Council on Exercise commissioned a study measuring rectus abdominis and oblique muscle activation in 13 core exercises. According to the results, the five most effective exercises for the rectus abdominis are the bicycle crunch, the captain’s chair (an ab hold variation), an exercise ball crunch, a vertical leg crunch/pike crunch and a torso track (a kneeling plank variation). If you have access to a gym and equipment to perform those exercises, try two 60-second sets of each, moving in a two-count rhythm, to form an effective 10-minute workout.

Getting sculpted abs isn’t an overnight process, so it’s important to develop a plan that you know you can stick with through time. To get the best results, mix ab workouts with regular cardio activity and pay as much attention to your diet as you do your exercises. Keeping calorie counts in check and focusing on whole, natural foods that are rich in fiber, protein, healthy fats, complex carbohydrates, vitamins and minerals will keep your body fueled for workouts, boost your physical health and improve your appearance.