Alternating Sets (also called Jump Sets) in weight training is when you pair two exercises and perform them similar to a superset. However, supersets usually have minimal or very short rest periods between exercises.
With alternating sets you will be using full rest periods (typically 1-3 minutes) between each set while you alternate (jump) back and forth between the two exercises.
You will complete one set of the first exercise, then have a full rest period, complete one set of the second exercise, then take another full rest period.
This is one alternating set which you will now repeat for as many total sets as you want.
The rest periods are usually constant for simplicity but they don’t have to be.
So the main difference between alternating sets and supersets is really just the use of full rest periods between each exercise and set.
Why Should You Use Alternating Sets?
When you train two or more muscle groups in a single workout, the typical way is to perform all sets of one exercise (with rest in between each set) before moving on to the next exercise and performing all of the sets for it.
The amount of work performed by each muscle group will be the total weight lifted in the time it takes to complete the sets along with the rest taken in between them.
That’s best if your goal is to fatigue the muscle since you will be completing the most work in the least amount of time for that exercise (also called workout density).
Incomplete rest and muscle fatigue are some of the requirements for creating metabolic stress, which many recognize as one of the main ways to achieve muscle growth.
However, if you’re interested in using the most weight on each set and maximizing strength levels to stimulate the most type II muscle fibers (which have the most growth potential), performing all of the sets in a row for one bodypart first will result in less weight being used because of muscle fatigue.
This will create an imbalance between the level of training intensity that you can perform for each muscle group. Generally you will have more energy at the start of a workout and therefore during the first exercise, which means you’ll be able to train harder and lift more weight for that muscle group you start with.
As you progress through the workout your strength and energy levels will drop off and by the time you get to the last bodypart you will usually have less energy.
To maximize strength levels you need to maximize your rest periods and complete each exercise while you have the most energy. Alternating sets allow you to do that!
By using alternating sets and jumping back and forth between exercises you are able to train both muscle groups with high intensity (the heaviest weight) right from the start and the training volume will be higher because you are using heavier weights.
It’s also important to note that when using alternating sets your workout time will NOT increase.
Your workout time will be exactly the same if you had done all the sets of one exercise first before all of the sets for the second exercise (assuming you use the same rest periods in both cases).
The only thing changing is the order in which the sets and exercises are completed while simultaneously maximizing the rest periods between sets for the same exercise.
Jumping between antagonistic (opposing) muscle groups is the most common way to use alternating sets.
Typical examples are biceps/triceps, chest/back, quads/hamstrings but it can also be used for non-related muscle groups such as chest/biceps, legs/shoulders, forearms/calves, etc.
The choices are the same as when using supersets (see superset method), just replace the no (or short) rest periods between exercises with a full rest period.
When to Use Alternating Sets Vs. Supersets
Personally, I like to use alternating sets between the big compound exercises like squats, deadlifts, bench press, etc. to optimize strength levels as using supersets with these exercises can be difficult (exhausting).
I find supersets are best for the less demanding isolation exercises like leg extensions or leg curls and even with smaller bodyparts (like biceps, triceps, forearms, calves, etc.) which recover more quickly.
Overall, it all comes down to your goal!
If you want to create the most muscle fatigue you would use supersets.
If you want to maximize strength levels you would use alternating sets.
Ultimately, I rotate both in my training to maximize muscle growth.
Modified Alternating Sets
The method above is probably the most common way to perform alternating sets. But one modification some people use instead of switching exercises during every set is to do a few sets of the first exercise before moving on to the second exercise.
The number of sets completed for the first exercise depends on how long you can maintain your strength levels.
Once your strength on the exercise drops significantly, you would move on to the second exercise. You would then continue to repeat this pattern.
This method allows for heavier weights than supersets, but still results in fatigue since you’re completing several sets in a row for the same exercise and bodypart.
If you want to maximize strength and performance, the traditional way where you jump between each exercise on every set with a full rest period would be the best to use.