If you haven't used a jump rope since you were a kid, you may have forgotten what a fun form of exercise it can be. But more importantly, you might not know that it's crazy efficient from a cardiovascular standpoint. Just 10 minutes of jumping rope can equal a half-hour of jogging, and you can take the thing anywhere — hotel rooms, at the park, around the neighborhood, etc.

There are companies that would charge you an arm and a leg for a basic jump rope. Ignore them and just get the supremely affordable XYLsports PVC jump rope. It's not too heavy or too light, the soft foam grips are comfortable to hold, and the bearings in the handles keep everything turning smoothly.

The rope is 9'8" by default, and if you need it any shorter than that, it's relatively easy to adjust: Pop off the end cap, feed a little of the rope through, pull the plastic clip to the desired length, and snip off the excess before putting the cap back on. I recommend being conservative about how much you cut off though. You can always do a little trial-and-error that way, but you can't go back if you remove too much length.

This jump rope is just $7 on Amazon.