Jumping jacks were a staple of my childhood calisthenics routines — although even by the age of 12, I was already questioning their usefulness and practicality. During Little League practice, they were usually inserted in a single set of 10 sometime before a 30-meter sprint to and from the fence. Meanwhile, during middle school PE, they were installed somewhere between cross-legged toe touches and deep side bends.
Despite the ubiquity of jumping jacks, though, I never really felt challenged by them. In fact, almost to a man, my coaches would refer to them as a warm-up.
That said, my distrust of jumping jacks’ effectiveness never stopped me from doling them out to my personal-training clients as a form of active rest if I was struggling to come up with a quick calisthenic movement for them to perform. That also didn’t stop me from watching in awe as Lt. Cmdr. Heinz Lenz — the longtime and legendary physical education instructor of the U.S. Naval Academy — forced my older brother and his many Midshipman classmates to endure several intense rounds of jumping jacks as a facet of each morning’s 40-minute training routine during my sibling’s first year in Annapolis.
So in theory, if jumping jacks were good enough for a legitimate legend like Lenz, they should be more than good enough for me, too.
Does that mean you like them now, or do you still think of them as wasted movement?
No movement is ever “wasted” in a pure sense. I suppose it all depends on what benefit you intend to get out of the motion, along with what you could be doing in its place. If your goal is to fill the 30 seconds of time between your pull-ups and your push-ups with a form of active rest simply for the sake of burning a few extra calories and keeping your heart rate up, jumping jacks might be beneficial. But if you’re hoping to break the world record for the deadlift and you decide to replace your sets of rack pulls with a few rounds of jumping jacks, you’ve probably made an unwise decision.
Okay, but what do jumping jacks actually do to physically benefit me?
By performing a series of tiny jumps in place, it will quickly become evident that the jumping jack recruits the muscles of your calves, quads and hamstrings to propel you the inch or two off the ground necessary to complete them.
Meanwhile, swinging your arms up into the air and then allowing them to fall back down to your sides, clearly involves the use of the muscles in your shoulders — primarily the medial deltoid muscles.
On top of the muscle activity involved in the performance of a jumping jack, the repeated motion will have a cardiovascular benefit similar to that of jumping rope. Like jumping rope, the movement of a jumping jack is generally confined to a very small space. If anything, ropeless jumping is probably the most tangible comparison I can draw between the jumping jack and another widely performed exercise.
Got it! So it’s a cardiovascular exercise similar to jumping rope, and it also works the muscles of my upper and lower body.
You need to slow all the way down with an analogy like that, because that sort of gross oversimplification can do you far more harm than good.
Despite what some people might tell you, jumping jacks are not a full-body workout in any pure sense of the term that most people would find acceptable. Think about the motion of your legs when you run, and how the muscles of your legs propel the weight of your body both forward and upward, one foot at a time. Now consider how jumping jacks require the use of both legs working in unison to push you exclusively upward. While we’re at it, further consider how your shoulders swing your arms forward and backwards one at a time as you run.
Have you ever finished running and thought about the pounding your legs received, especially your knees? I’d venture to guess the answer is “yes.” Now, have you ever finished running and thought about the tremendous fatigue you felt in your shoulders? I’d be willing to bet the answer is “no.”
This is because your feet made direct contact with the ground during your run, but your shoulders were swinging your arms freely through space against no resistance at all. While there is a little more gravity at play when you swing your arms through the wide arc a jumping jack demands, they’re still being permitted to fall freely back down to your sides, which requires the disengagement of muscles more than it requires any coordinated thought of your own.
Furthermore, jumping rope requires tremendous timing and concentration. It also allows for far greater variance in the movement pattern. You develop astonishing levels of spatial awareness and mind-body connection while jumping rope, and you also improve your coordination and balance. Jumping jacks can’t even come close to replicating these benefits.
In essence, you should begin with an idea of exactly what you’re hoping the jumping jack can do for you, and then determine if there’s a more suitable way to acquire the same results — or even better results. If you have access to any other form of cardiovascular training, it can probably do more to improve your physical fitness than a jumping jack ever could. Realistically, I don’t even have the space to get started on how many upper- and lower-body exercises are more efficient, thorough and effective at training your entire body than jumping jacks — and this includes the muscles that jumping jacks could theoretically be said to target.
Oh, wow! That does make a difference in how I think about jumping jacks!
It does. Also, I honestly hate that it’s to come to this, but I can’t advise you strongly enough to jump rope instead of doing jumping jacks whenever both are reasonable workout options and you have the ability to choose between them. The coolness-factor difference between the two is so profound that it’s practically immeasurable. If you spend enough time jumping rope at the gym, there’s a decent chance someone is going to ask you if you’re a trained fighter. If you spend a similar amount of time doing jumping jacks, there’s just as good of a chance that someone is going to ask you why you insist upon training like a nine-year-old soccer player.