We rounded up five of the most effective tummy toners around. Work three or four of these exercises into your routine (easing them in will minimize soreness). Do the number of reps indicated, resting one minute between moves. The only equipment you will need is a hand towel. Washboard abs, here you come!
Pike 90
Lie faceup; raise legs until perpendicular to floor, feet flexed. Lower right leg so it hovers 1 or 2 inches off floor and place hands lightly behind head. In this position, do 15 crunches, lifting chest toward ceiling and lowering. Switch legs and repeat.
Crunchy frog
Sit with knees bent, feet flat. Keeping legs together, raise feet several inches and bring knees toward chest. Wrap arms around knees without touching legs. Extend legs and stretch arms to sides, palms forward. Return to wrapped-arm position; repeat. Do 15 reps.
Tornado
Stand with feet hip-width apart, right leg in front of left, right foot turned out. Bend elbows and raise arms out to sides at shoulder level (like goalposts). In one motion, raise right knee to lowered right elbow. Return to start; switch sides and repeat to complete one rep. Do 15 reps.
Corkscrew
Lie faceup. Press legs together and raise them toward ceiling until they're at a 90-degree angle, with knees slightly bent and toes pointed. Raise butt and legs off floor using ab muscles; twist legs slightly to left. Repeat, twisting to right, for one rep. Do 15 reps.
Side arm balance
Start on floor on knees. Lean to left and place left hand on floor under shoulder; extend right arm up and to left, palm down. Straighten right legs out to right with foot on floor, resting on left knee. Hold for 5 breaths. Return to start; switch sides. Repeat twice per side.
By Lucy Danziger, SELF Editor-in-Chief