9 intense arm workouts you can do virtually anywhere without any equipment

Making time for a solid arm workout isn't always easy, especially if you're in need of weights and other equipment.

But when you're on the road or have a few minutes to spare between events, it can be nice to have some quick, virtually equipment-free arm workouts up your sleeve.

To help us out, we asked New York University physical-therapy professor Marilyn Moffat, who also wrote the book "Age Defying Fitness," for some of her favorite arm workouts that don't require weights.

Here are the nine she gave us, including modifications to help you personalize your workout. Feel free to mix and match, or just do one exercise on its own. Repeat or hold each exercise until it gets to be too much, building up at your own pace. And remember: If you have any unusual pain or problems with the exercises, stop doing them and consult a physical therapist.

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Exercise #1: The dreaded plank. Keeping your arms directly under your shoulders, hold this pose for at least 30 seconds, until it gets to be too much.

Something to keep in mind while in these poses: To better distribute your weight, spread your fingers as wide as possible. You should be able to feel the difference along your arms.

For a modification, try putting your forearms on the ground. You'll still feel the stretch along your arms (not to mention torso and legs).