Jumping jacks can be good but you can also modify them in many ways. Find out how to do side jacks and what the benefits are.
Side jacks are a variation of jumping jacks where you take a step sideways with one leg instead of jumping outward with both legs. Similarly, you only raise one arm upward instead of two.
This different movement makes it so side jacks are easier on your knees but less intense than regular jumping jacks. In turn, you also get the exercise benefits to a lesser extent.
So side jacks are mostly good for people who want to do jumping jacks in a more low-impact way.
They work a few more muscles than more typical low-impact cardiovascular exercises like cycling or walking.
Additionally, side jacks can be useful for warming up, dynamic upper back stretching, or improving coordination.
If or when your body can deal with regular jumping jacks and other good cardiovascular workouts, these can likely offer more benefits.
Even if you just don’t have any shoulder issues, step jacks where you still move both arms can be a more effective option than side jacks.
How to do a side jack
Take the following steps to do a side jack:
- Stand upright with your feet together and your arms by your sides.
- Take a step sideways with one leg until your feet are wider than shoulder-width apart. At the same time, move the slightly less than stretched arm of that side upward and sideways. Your arm should point about straight up when you finish the step with your leg.
- Return the leg from the previous step to the center so that you are back in starting position. Similarly, lower your arm sideways so that it is back by your side.
- Repeat starting at step 2 but with your arm and leg on the other side.

Side jacks are a relatively straightforward movement in terms of exercise technique. You mainly want to pay attention to how far you can move your arms in a comfortable way.
When you get comfortable with the side jack movement, you can consider picking up the pace to get the benefits to a larger extent.
Muscles worked with side jacks
The main muscles worked with side jacks are your hip adductors (inner thigh muscles), hip abductors (outer thigh muscles), calves, quadriceps (front thighs), deltoids (shoulders), and latissimus dorsi (middle/upper back).
You can say this side jacks also engage your core muscles, glutes (butt), hamstrings (back thighs), chest, and trapezius (upper back) to some extent.
All of these muscles are similar to the body parts you work with regular jumping jacks. Side jacks do work these to a lesser extent.
Both of these exercises are not good for actually growing and strengthening the muscles you work.
That being said, side jacks could still offer small improvements in terms of muscle endurance and muscle health.
Side jacks benefits
As you may suspect by now, the results you get from side jacks are mostly similar to the benefits of jumping jacks but to a smaller extent due to the lighter movements.
Some of these benefits include:
- Easier on your knees: Jumping jacks can be uncomfortable for people with knee and ankle pain. Side jacks allow you to do a version that is easier on these body parts.
- Can help with losing weight: Since side jacks are likely more intense than your daily activities they should also burn more energy. In combination with good habits in other areas, this can help you lose weight.
- Can improve cardiovascular health: The movements in side jacks will require your heart, lungs, and blood vessels to work harder. This can lead to a healthier cardiovascular system.
- Flexibility and mobility: The arm movements in side jacks could be enough to improve mobility and flexibility in and around your shoulders.
- Improves mood: Moving more intensely than usual tends to increase to what extent your body creates feel-good hormones. In turn, doing side jacks could improve your mood.
- Balance and coordination: While to a lesser extent than regular jumping jacks, side jacks still require some amount of balance and coordination. This could be enough to see improvements in these skills.
- Better muscle endurance: Engaging your muscles with side jacks for extended amounts of time could improve their endurance.
- Improves sleep: Implementing an exercise routine that includes side jacks can benefit your sleep.
- No equipment or location required: You can do bodyweight exercises like side jacks without investing in exercise equipment or moving to a specific location.
You can get many of these benefits to larger extents from more vigorous exercises but for the right people, side jacks can be a good choice too.
Side jack alternatives
By now, you may conclude that your body is able to deal with these more vigorous side jack alternatives. A few of these are:
- Jumping jacks
- Side shuffles
- Lateral raises
- Elliptical machine
- Cycling
- Weighted leg adductions or abductions
- Lunges
What side jack benefits you like the most, what your body can deal with, and what you like doing are details that influence your decision between these alternatives.
Are side jacks a good exercise?
Side jacks can be a good exercise for people who find regular jumping jacks or similar movements uncomfortable on their ankles, knees, and lower back.
By taking steps instead of jumping, you can still engage your cardiovascular system, muscles, and coordination but in a low-impact way.
Side jacks can also help you warm up and offer dynamic latissimus dorsi (middle/upper back muscle) stretching.
That being said, if your body can deal with them, more intense side jack alternatives (both low-impact and high-impact options) can offer more benefits in shorter amounts of time.
Personal preference matters too but from a results perspective, many people will prefer these alternatives.