I did 100 jumping jacks every day for a week — here’s what happened

This simple full-body exercise works your heart and muscles in one hit to help you burn fat, strengthen bones and shape up.

Smiling young fit woman wearing headphones doing jumping jacks outside at the bottom of some steps
(Image credit: Getty Images)

I always think of jumping jacks as being quite an old-fashioned exercise. I remember them from primary school – ‘be a star!’ – and from Jane Fonda DVDs and Mr Motivator workouts on breakfast television, but since then, I’ve only ever done them during a few military-style bootcamp workouts. 

Put it this way; they’re not my first choice of cardio exercises to get my heart rate up. In fact, they’re not in my top 20. But they say that oldies are goodies for a reason, so when I was asked to do 100 jumping jacks a day for a week, I er, jumped at the chance. 

Because who needs to go running outside in freezing cold temperatures when you can find a small space in your home and bang out 100 hundred of these beauties to work up a sweat and burn calories? Not to mention that they’re experiencing something of a resurgence thanks to the #100jumpingjackschallenge on TikTok. So, with that in mind, I donned my high-impact sports bra and best workout shoes (both are essential for this exercise), and got jumping.  

 How do I perform jumping jacks? 

  • Stand up straight with your feet together, your toes pointing forwards, and your arms by your sides.
  • Next, slightly bend your knees and jump your feet out to the side, slightly wider than shoulder-width apart, while simultaneously raising your arms out to either side and above your head.
  • Reverse this pattern by returning to your starting position with arms by your side and feet together. 
  • Remember to keep your chest up, and your core braced to protect your lower back. Avoid twisting, slouching, or letting your knees fall in – keep your toes pointing forward.

If you’re a beginner, or you want to avoid placing any impact on your lower-body joints, do a modified jack instead, where you keep one foot on the ground at all times and alternate stepping your legs to the side. Both arms should still raise above your head.

What are the benefits of doing 100 jumping jacks a day?

Jumping jacks require zero equipment and can be done anytime, anyplace, so they’re great if you’re busy or on a budget. Often, you’ll see them used as a warm-up exercise, but jumping jacks are an extremely effective cardiovascular exercise for the heart and lungs that work well on their own or mixed into a HIIT workout if you want to get your heart rate up between strengthening exercises. 

Jumping jacks are a full-body exercise that works all the main muscles of your body, including the glutes, hip flexors, quadriceps, hamstrings, abs, and shoulders. They include both resistance and aerobic training, and the jumping action means they qualify as a plyometric exercise, so they can help you to build muscle, burn fat, increase your metabolism, and strengthen your bones at the same time without using weights, while also testing your coordination, mobility, and flexibility.

Young man doing jumping jacks on the pavement

"Keeping a steady rhythm, I managed to do my 100 jumping jacks in just over two minutes."

(Image credit: Getty Images)

I did 100 jumping jacks a day. Here’s what happened.

My fitness is at a fairly decent level right now, having already completed my 50 squats a day for a month, 100 burpees a day for a week and 100 kettlebell swings a day for a week challenges, so I wasn’t too worried about doing 100 jumping jacks a day if I’m honest. But that doesn’t mean I didn’t work up a sweat!

DAY 1

I did my 100 jumping jacks before lunch (repetitive jumping after eating is not recommended!). Keeping a steady rhythm, I managed to do my 100 jumping jacks in just over two minutes. By the end of completion, I was gasping for breath and pretty flushed in the face. But if anything, I felt ready to start a full workout. I didn’t, however, in case it affected my ability to do another 100 jumping jacks the next day.

DAY 2

I woke up feeling okay and got straight into my jacks before breakfast. Yes, I was out of breath and sweaty, but that’s kind of the point with cardio exercise! After breakfast, I decided to look into the effects of doing 100 jumping jacks a day. I soon discovered that your body would burn around 10 calories for every minute (opens in new tab) of jumping jacks, or around 0.2 calories per jumping jack. Doing the maths, that meant my two minutes of 100 jumping jacks added up to burning approximately 20 calories.

That didn’t sound like much for the effort, but I also came across some articles suggesting you should try doing three sets of 100 jumping jacks daily to see more benefits.

Of course, if you are a beginner, starting with 100 jacks a day is more than a tough enough challenge to begin with, and you’ll no doubt have to take plenty of breathing breaks to get them done, as well as keep an eye on your exercise form to make sure your knees don’t fall in. 

Because while this exercise is simple, that doesn’t mean there’s no risk of injury, especially if you have weak ankles or an existing knee or hip injury, in which case you should opt for the modified, impact-free jacks I mentioned earlier.

Young fit female doing jumping jacks in front of red garage doors photographed from behind

"The key to doing so many jumping jacks, I think, is to play a favourite motivational tune with a strong beat so you can jump along in time to the music."

(Image credit: Getty Images)

DAY 3

I still felt okay, so I decided to up the ante by doing three sets of 100 jacks strategically placed before I ate breakfast, lunch, and dinner. Of course, this was made easier because I WFH, and I can wear my activewear and trainers all day, but I understand this approach might not suit everyone. 

The key to doing so many jumping jacks, I think, is to play a favourite motivational tune with a strong beat so you can jump along in time to the music. I found that doing 100 jumping jacks to a cracking tune helped to get the blood pumping, blow away the cobwebs, and boost my motivation to get on with the rest of my day.

DAY 4-6

I felt a little achier, as you’d expect from doing 300 jumping jacks a day, and my knees felt a bit stiff, but I was still down to continue the challenge, as I did on days five and six.

DAY 7

I felt almost sad that the challenge was over. Because what I discovered is that fitting a sudden burst of activity into your day is not only beneficial for your body but for your mind too - and I don’t think it matters whether you’re doing 100 jumping jacks or 300 jumping jacks; the results are the same.

Young fashionable woman with curly hair walking on the street and listening to the music

"Randomly doing some exercise can really help to reset your mind and mood, as well as burn a few calories"

(Image credit: Getty Images)

If you’re anything like me, and you find it really easy to stay chained to your desk and forget to move, setting yourself a challenge to get moving once in a while can be really beneficial, and I found that I often felt super-energised afterwards. On many occasions, I felt inspired enough to take my dog out for a quick walk or get into a full workout. 

By the end of the week, it’s fair to say I felt fitter and more mobile, but I also felt more motivated for life in general and a great deal happier (the cheesy tunes I was listening to help with that, I think). 

The point is, it doesn’t have to be jumping jacks (although they’re a great place to start): it can be dancing around energetically with your arms in the air or running up and down the stairs a few times. But randomly doing some exercise can really help to reset your mind and mood, as well as burn a few calories!

Joanna Ebsworth

Jo has been obsessed with writing and fitness since her teenage years and spent all her pocket money on magazines and workout VHS tapes. When ITV cancelled Gladiators – causing her dreams of becoming the next ‘Jet’ to crash and burn - she decided to combine her passions and become a fitness writer instead. A qualified PT and author of several fitness guides, she has spent the last 15 years writing for many of the UK’s most respected newspapers, magazines, and online publications. When she’s not interviewing celebrities and athletes or testing fit kit, she can be found watching YouTube breakdowns of the latest MCU releases.