The first time I ever did a jumping jack was as a warm-up exercise during T-ball practice. At the time, the jumping jack seemed like a fun way to hop around, and a welcome change of pace from all of the stretching that I loathed. Besides, we never had to do more than 10 jumping jacks at a time, so it’s not like we were exhausted when each round reached its conclusion.
Fast forward to middle school gym class, where I was also required to do daily jumping jacks before we moved on to basketball, flag football, running or whatever else was on the P.E. teacher’s agenda that day. We still, though, never progressed beyond 10 jumping jacks at a time, and I vividly recall wondering what the point of them even was.
That’s where I left jumping jacks until roughly 2002, when I needed to come up with active-rest exercises for my personal training clients to engage in when they were between lifts. Rightfully thinking that push-ups brought too much intensity, I suggested jumping jacks, and I was as surprised as anyone to learn that they were more than sufficiently taxing for the task at hand.
But short training bursts aside, if I really wanted to push it to the limit with respect to jumping jacks and make them my preferred brand of post-lifting cardio, how many would I have to do to burn a significant number of calories — 100? 200? 1,000?
How would you figure out such a thing?
The Compendium of Physical Activities is what the designers of cardiovascular training equipment consult when they’re searching for formulas to apply to the settings of treadmills, stepmills, rowers, ellipticals and so forth. Far from being limited to established exercises, the Compendium applies numeric values of training rigor to everything from gardening (watering your lawn has a score of 1.5) to sex (vigorous sex registers at a surprisingly low 2.8), and even to participation in religious services (praising with dancing scores a astonishingly high 5.0).
So where do jumping jacks land? An 8.0, which I’m going to throw a flag on because vigorous kettlebell training was awarded an identical score, and vigorous rowing and stepmilling registered only slightly higher at 8.5 and 9.0 respectively. Either the folks at the Compendium are way off, or I’ve been doing jumping jacks all wrong for a great many years.
Anyway, where do fitness estimators place jumping jacks in terms of their caloric burn? One respectable estimator places the number between 8 and 16 calories per minute depending upon your weight and the intensity of your movement. Frankly, that’s a strikingly wide range, and being the conservative estimator that I am, I’m going to affix a burned-calorie value of nine calories per minute to our formula simply to keep us from wildly overestimating the number of calories you’ve burned.
If we assume that a normal person takes two seconds to complete a full jumping jack — arms and legs out, then arms and legs together — that’s 30 jumping jacks per minute and nine calories burned, or about 0.3 calories per jack.
So, how much jumping of jacks is required to incinerate 100 calories via this hastily spawned, only somewhat reliable formula that I made up 12 seconds ago? Somewhere between 333 and 334.
That’s a lot of jack jumping.
It’s definitely a whole lot of flailing arm movements.
You’d better believe it.
In the hidden track “Lyrical Exercise” from his critically acclaimed album The Blueprint, Jay Z claimed to “get jacks jumpin’, 36 sets.” Well, 36 sets of 10 jumping jacks is about what it will take for you to meet the target of 100 calories burned, and it sounds like one of the most boring workouts in the world. This is because jumping jacks are one of the most mind-numbing exercises you can do for more than 30 seconds. There’s no focus required, nor is there any mental or visual stimulation along the way. Most people are likely to give up out of sheer boredom long before reaching the 100-calorie mark.
If you want my advice, set aside the jumping jacks and grab either a true jump rope or a ropeless jump rope instead. You’ll work similar muscles, you’ll have a lot more fun and you can pretend you’re some badass fictional fighter like Creed as opposed to an elementary school T-ball player.