Sean Hyson is the group training director of Men's Fitness Magazine and the author of The 101 Best Workouts of All-Time.
Seeing results is about getting out of your comfort zone. And when you're traveling and find yourself without a gym or somehow unable to do your regular routine, you're well out of that zone already. So you may be forced to use different exercises or training implements to complete a workout. What follows are six different exercises taken for your abs—one for each training tool you're likely to have access to, plus body-weight alone—so you can stay on track no matter where you are.
Barbell Straight-Leg Situp
Almost any place that advertises "fitness" will have a barbell of some kind. You won't need much weight, if any, to perform this exercise, which combines a full situp with an overhead press. It's a brutally hard move, especially for those with long arms or legs, as your muscles will have more to stabilize.
How to do it: Lie on the floor holding an empty, or lightly loaded, bar over your chest, as in the top of a bench press. Your legs should be extended on the floor in front of you. Perform a situp, raising your torso until it's vertical. Keep the bar over your head, so it drifts back to an overhead press position at the top of the situp.
Band Pallof Press
Most people don't know how to train their abs with a band, but it can be as simple as standing still. The Pallof press doesn't look hard, but it forces you to keep your torso locked in place while the band is trying to twist it. This works your core deeply, and your oblique muscles (side abs) in particular.
How to do it: Attach a band to a sturdy object at chest level. Grasp the free end with one hand over the other and step away from the anchor point to put tension on the band. Turn perpendicular to the anchor point, stand with feet shoulder width, and extend your arms in front of you. The band will try to twist your body toward it—resist. Bring your hands back to your chest and then press again.
Suspension Trainer Sprinter
Moving your limbs while your torso stays solitary makes for a deceptively hard ab workout. When you pump your legs like you're running, the rest of your body wants to move too. It takes a lot of bracing from your core to prevent that movement. That's the idea behind this exercise, called the sprinter, which also gets your heart rate up so you burn more calories, helping you to uncover the abs you've worked hard to build.
How to do it: Place your feet in the foot cradles of the trainer and get into pushup position with your hands on the floor. Drive one knee to your chest while the other leg remains extended. Now drive the opposite leg to your chest while you extend the other back. Continue so it looks like you're running in place.
If you've ever worked out with a partner, you've probably done situps and tossed a medicine ball back and forth to each other. The med-ball slam is a good substitute when you don't have a partner, or your gym doesn't have a brick wall you can throw the ball against. The slam targets your six-pack muscle directly.
How to do it: Stand with feet shoulder-width and hold the medicine ball with both hands. Brace your abs and reach your arms overhead and back, with elbows almost locked, until you feel a stretch in your abs. Explosively throw the ball onto the floor and catch it on the rebound.
Ab wheels are popular training tools, and work well to stretch and strengthen the core. But not every gym has a wheel, and when you can find one, it's often broken or doesn't roll properly. A Swiss ball is a good stand-in.
How to do it: Rest your forearms on the Swiss ball and extend your legs behind you. Brace your abs and roll the ball forward as you extend your arms and hips. When you feel you're about to lose tension on your abs, roll yourself back.
Body-Weight Star Plank
You know the plank already—get into a pushup position, then lower your forearms to the floor and hold for time. When that gets too easy, you need to move on to a harder variation. The star plank is a great option, and a favorite of military personnel who often have no equipment around to train with but stay in exceptional shape.
How to do it: Get into pushup position. Move your arms and feet apart as wide as possible—your body will make a star shape. Hold the position with your torso straight and abs braced for 30 seconds.
For more ideas on how to train with any piece of equipment, pick up 101 Best Workouts Of All Time at 101bestworkouts.com.