Half Jacks: How To, Muscles Worked,…

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You can sometimes leave out part of an exercise to get different results. Discover how to do half jacks and what benefits they offer.

The term “half jacks” is used to describe two different movements. The first one is jumping jacks where you only raise your arms horizontally but not vertically.

The effects of this variation will be similar to regular jumping jacks but that form of half jacks can be more comfortable for your shoulders and easier to do at fast paces.

This article focuses on the second type of half jumping jacks. This is another jumping jack variation where you only do the leg movements and just keep your arms out of the way.

By doing this, the exercise becomes easier to do at higher speeds and becomes better for training cardiovascular health.

The main potential downsides of half jacks are that you don’t get the same shoulder warm-up and do not engage your shoulder and back muscles.

Additionally, there are still exercises that are even more effective than half jacks for training cardiovascular health.

How to do a half jack

Take the following steps to do a half jack:

  1. Stand up straight with your feet together and your arms where they are not in the way of your moving legs. For example, you can put your hands on your hips.
  2. Jump a small amount in the air and move your legs sideways and outward.
  3. Land with your feet wider than shoulder-width apart and instantly jump back into starting position. You want your legs to be slightly less than stretched when landing in both positions.
How to do a half jack

Half jacks are a relatively straightforward exercise. The main thing to keep in mind is to keep your legs slightly less than stretched when landing.

You will likely get used to the half jack exercise relatively fast. At this point, you can pick up the pace to train your cardiovascular health to a larger extent.

Additionally, you can hold some type of weight or wear a weighted vest to make half jacks more challenging on both your cardiovascular system and leg muscles.

Half jacks muscles worked

The main muscles worked in half jacks are your hip abductors (outer thighs), hip adductors (inner thighs), quadriceps (front thighs), glutes (butt), hamstrings (back thighs), and calves.

You can also say your core muscles have to work to some extent to keep your upper body upright.

The main difference between jumping jacks and half jacks is that half jacks don’t work your deltoids (shoulders) and latissimus dorsi (middle/upper back muscle).

This does make it easier to do half jacks at higher speeds but also reduces in how many areas you can potentially get muscle endurance improvements.

In both half jacks and jumping jacks you should not really expect any actual muscle growth. At the same time, that does not mean you are doing nothing good for your muscles.

Half jacks benefits

Besides that lack of upper body engagement, half jacks are still similar to jumping jacks in that they offer many of the same benefits. Some examples of these include:

  1. Can improve your cardiovascular health: Your heart, lungs, and blood vessels will have to work harder during half jacks to move nutrients to the right places. This can strengthen your cardiovascular system.
  2. Muscle endurance: Half jacks will likely not be hard enough to grow the strong leg muscles but they could still offer muscle endurance improvements.
  3. Improves sleep: Exercising throughout the day can improve your sleep at night. This principle applies to half jacks too.
  4. Balance and coordination: Half jacks involve a certain challenge in terms of balance and coordination. This can potentially benefit your skills in these areas.
  5. Can benefit weight loss: The vigorous movements in half jacks will likely burn more calories than usual. In combination with good lifestyle habits, this can help you lose weight.
  6. Improves mood: Another consequence of vigorous movements is that they tend to make it so your body produces more feel-good hormones.
  7. No equipment or location required: You can do half jacks without investing in fitness equipment or spending time driving to a different location.

These benefits are definitely not unique to half jacks but they can still be a good option if the things above align with your training goals.

Half jack alternatives

It is also possible that you do not completely like the half jack exercise. In that case, you can also consider some of the alternatives below to get similar benefits.

  • Side shuffles
  • Resistance band crab walks
  • Jumping jacks
  • Running
  • Weighted leg adductions or abductions
  • Cycling

What areas of your health you want to improve is an important detail when deciding between these half jack alternatives.

Are half jacks a good exercise?

Half jacks can be a good exercise to train your cardiovascular system in a way that engages your inner and outer thigh muscles to a certain extent.

Additionally, you can use this exercise to improve your coordination and to warm up before more intense workouts.

At the same time, it is worth mentioning that workouts like running, cycling, swimming, etc. could be more convenient to train your cardiovascular health a lot.

Some people will also prefer the upper body movements of regular jumping jacks in certain situations like warm-ups.


What are half jacks?

Depending on who you ask, half jacks are a jumping jack variation that either involves smaller arm movements or no arm movements.

What is the starting position for half jacks?

The starting position for half jacks is standing upright with your feet together and your arms out of the way. This can mean your hands on your hips, in front of your chest, or something else.

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Matt Claes founded Weight Loss Made Practical to help people get in shape and stay there after losing 37 pounds and learning the best of the best about weight loss, health, and longevity for over 4 years. Over these years he has become an expert in nutrition, exercise, and other physical health aspects.