If you have already been training for a while, you probably already know about “super-sets”, if not, let me explain shortly: The standard or common way would be to “do a set”, “take a 1-2 minutes break”, “do another set”, “take a 1-2 minutes break”, and so on… While super-sets being “do a set”, “take a 10-15 seconds break” (which is approximately the time it takes to set yourself up for the next exercise), “do a set of another exercise”, “take a 10-15 seconds break”, “do a set of the first exercise”, and so on…
So super-sets can either make your overall workout shorter, or allow you to train more in the same amount of time, while also building a little more cardio because the shorter breaks don’t let enough time for your heart to go back to its resting rate.
Now that we know what super-sets are, we can introduce “double-sets”, which is just a name I came up with, so it could already have an official name that I’m not aware of… I guess it could be similar to what some people call “combo-sets” or “complexes”.
In a super-set, you replace the break by another set. In a double-set, each rep of a particular set is composed of two different movements. So depending of how intense you want to train, you can either use double-sets with regular 1-2 minute breaks or even super-set them with other double-sets.
But how do we combine two exercises into one? Exactly as you would expect, by doing one after the other, than count one rep.
Here’s an example: If we want to train legs, than we could double-set some reverse lunges and single-leg RDLs (RDL = Romanian DeadLift). So we start by doing a full reverse lunge with the left leg (meaning that the right leg moves to the back while the left leg lunges), then, instead of continuing with another lunge, we keep our right foot in the air and then do a RDL with our left leg, and we got our first rep. Then we start again until we’ve reached the amount of reps we were aiming for. When we’re done with the left leg, we do the exact same thing with the right one.
As you can see, I picked two complementary movements that can be easily chained together. Of course, some combinations won’t work that well, like if we tried to double-set calf-raises and push-ups. So there has to be some experimentation on your part to find what works well with your workout plan, or adjust your plan to fit some movements that allow for double-sets. The key would be to combine exercises that you can either lift the same weight (changing dumbbells each time wouldn’t make much sense) and/or which the transition between the two is easily done, like in the previous example.
The advantage of double-sets, like for super-sets, is that you can also fit more work inside the same time frame, or just reduce your overall workout time. But there is also another benefit that I found while doing it, depending on which exercises are put together. It can help you work harder on a single muscle, for example, if I do triceps extensions on a pulley, I can alternate between an over-hand and under-hand grip each rep to work the muscle in two different ways at the same time. This one is particularly interesting because I can really feel which “section” is working harder than the other on each alternating rep.
At the end of my workout, I often add a few exercises aimed towards “forgotten” or “lagging” muscles, like the rotator cuff and the low and medium trapezius for example. I usually do face-pulls for the traps and a variation of that move that targets the rotator cuff. They fit really well with double-sets, because they are both done in the standing position with a band/pulley in front of me at face height. The only thing that changes is the path of my arms when I pull them towards my back, which is really easy to do.
Also, just like you could super-set three different exercises, you can also do triple-sets, which is the same thing as double-sets, but with three different moves needed to amount to one rep. The one I use the most is an explosive deadlift (there is a name for it that I can’t seem to find, the one that makes the bar/dumbbells fly up to your shoulders), followed by a shoulder press then a front squat.
So as with any other technique, this is just another tool in your toolbox, I wouldn’t recommend using it all the time for every movement, but to fit it where it makes sense.