In other exercises—like a row or pull-down, for example—the resistance is flip-flopped: It’s heaviest when your muscles are at their weakest, and lightest at their strongest point, which is also a plus as it can help you progress through your strength training by working on the point where you struggle the most, Dr. Reiner explains.

What’s more, bands are an “excellent way” to ease into strength training or rehab from injury, Dr. Reiner says. That’s because they create a slower progression compared to weights, since you can make exercises more challenging in smaller increments by simply shortening the length of the band (versus picking up the next set of weights, which may be several pounds or more heavier.) “You can inch your way toward full-on strength training that way,” Dr. Reiner says. Plus, in a rehab (or prehab) scenario, you can use them to isolate specific muscle groups and work in different planes of motion simply by changing your position to the band, Dr. Reiner explains, which can be an easy, effective way to pinpoint specific areas.

They’re also stellar for getting in some form of strength work when you have limited access to other equipment, she adds, like those times when you just can’t make it to the gym after work or are traveling with no weights at your disposal.

To boot, bands are budget-friendly (you can buy a five-pack on Amazon for $24), portable (just toss ’em in your gym bag or suitcase), and highly versatile (they work with tons of different exercises—from traditional strength moves like lunges, bridges, and presses to more stability-focused exercises like pull-aparts, clamshells, and lateral walks).

Lastly, the fact that they’re basically just oversized rubber bands can make them less intimidating compared to a bulky set of free weights. “It’s a lot less scary to look at a resistance band than a dumbbell,” Hart says, which can make them a more approachable tool for anyone new to, or otherwise overwhelmed by, strength training.

But there are some downsides worth knowing about too.

Besides the fact that bands can only provide strength training to a point, making them a not-so-great-choice if your goal is heavy gains, their shifting resistance level could hinder your strength gains through your full range of motion, if you’re relying on bands alone and no weights, Dr. Reiner says.