Swim cords are a great tool to help work swim specific muscles out of the water, and they can help your mental game tremendously when you can’t get in the pool because your schedule doesn’t mesh with lane swim times. Just loop them around a pole, tree, stair banister, shut the middle part in a doorway… and have at it. Gordo has some nice pictures illustrating a few swim cord exercises here. I would also recommend lying face down on a bench or (using a ball for even more of a core stability challenge) because this lets you feel bit more like you do in the water and this can help with muscle memory. Remember, you want to have a strong, high elbow catch, without totally losing your roll.
Swim cords can be a great tool for arm position awareness – just be sure to check yourself out in a mirror, or have a friend critique you, the first few times you do them to make sure you are keeping your elbows nice and high, and not putting unnecessary strain on your low back. A great thing to do is to use them on deck before jumping into the water, then try to mimic that feeling once in the water. Use your lats to pull the cord back with your forearm vertical - learn to engage your major muscles groups. They can also be good to use after swimming as a substitute for weights. Get your back muscles, pecs etc. in order to help balance your swimming muscles and prevent injury.
Sometimes if a particular swim workout is absolutely dragging on we’ll do something different and mix it up with a 5 x (200 swim / 2 minutes swim cord) set. They can also be handy to have for road trips to races (to get the blood flowing at rest stops or during ferry rides) and they are good for warming up before your swim start, especially if it is a super cold water event. Be sure to practice making this part of your warm up routine beforehand!
