I did 100 mountain climbers a day for three weeks, here's what changed

A core burner, there’s more than meets the eye to those nifty mountain climbers

Woman performing mountain climbers.
(Image credit: Getty)

Mountain climbers are a popular HIIT move, and are often incorporated into ab workouts, so when I was asked to do 100 of them a day for three weeks, I reveled in it.

Yes, I did 100 mountain climbers a day for three weeks just to see if it made any difference to my body. Even just a smidgeon. The rules of my challenge were simple: 100 mountain climbers a day, split however I wanted, for three weeks. Oh and to clarify, this was doing 50 on each leg.

I decided to incorporate these 100 mountain climbers into a workout for abs. There are two reasons for this; firstly, 100 mountain climbers a day, isolated away from other exercises, I don’t believe is going to do anything other than leave you a little breathless.

Secondly, when done properly, mountain climbers can contribute massively to activating the core muscles, so why not throw them in with my other ab-based moves, to really make the most of them!?

Not familiar with a mountain climber? Well, I’m not talking about actually climbing 100 mountains. That would be outrageous. Although, let’s hold that thought for a future challenge.

Anyway, let me enlighten you on how to do a (far easier!) mountain climber, on the floor.

To do a mountain climber - or 100 of them - start off in a high plank position, with the palms of your hands directly under your shoulders, core tight, and body in a straight line resting on your toes. Then drive the left knee towards the right elbow and as you move it back to the start position, bring the right knee up towards the left elbow. Keep alternating, all the while ensuring your arms stay straight and your midsection is engaged. 

I added these 100 mountain climbers into a 10-minute ab finisher for three weeks. Other moves I worked with were v-ups, crunches, planks, and Russian twists. Often, my 100 mountain climbers were split up, say into groups of 20 (10 each leg). And I would often slow the move right down to keep the core muscles under tension a little bit more, or I would race through them and reap more of a HIIT benefit from them.

So this is what went down during the mountain climber challenge…

Woman performing mountain climbers.

(Image credit: Getty)

1. My arms felt it, hard

Familiar with a high plank? It fires up your core muscles and also works your arms as your body is essentially propped up on the palms of your hands. 

So, with mountain climbers creating a bit of a balancing act as you bounce from one leg to the other, it’s going to work the arms even more.

My shoulders, triceps, and biceps felt it the most, and had I wanted to create even more resistance, I would have done these 100 mountain climbers whilst wearing a weighted vest. Can you even imagine the burn!?

2. My obliques were on fire

Throwing 100 mountain climbers in immediately after a bunch of other ab-based moves, felt like flames were rushing to my oblique muscles; the muscles that run down either side of your core. 

If you want to work the core muscles, then plank-based moves (such as mountain climbers) are more effective than crunches. Don’t just take my word for it; science says it too.

A study found that it’s integration exercises that activate your abs more than say, isolation exercises such as crunches. Integration exercises are those that work other muscles at the same time such as your arms, shoulders and back.

As a PT, I will always recommend that people include ab moves that target the entire core, rather than just crunches that will hit the top ab muscles but realistically, not much else. But our core contains so many other muscles, that when activated and developed, can help to really carve out the ‘toned’ midsection you may be craving.

3. No, you won’t get a flat tummy

If you could do 100 mountain climbers a day for three weeks, and burn belly fat and get the flat stomach that so many of us dream of, then I think every single human on this planet would have a flat tummy. 

In fact, I would make millions from packaging up and selling this new ‘easy flat tummy in 3 weeks’ hack. Everyone would buy it.

Realistically, a well-balanced diet, ideally a calorie deficit if you have a lot of weight to lose, and plenty of resistance training, consistently, over a fair long period of time (how long is a piece of string!?), is the way to get a flat tummy. And annoyingly for some, genes just dictate that fat tends to reside over the stomach area. So, it becomes even harder to burn it off.

4. It’s a brilliant HIIT move

Performed fast (whilst still maintaining a good form), mountain climbers certainly shot my heart rate up.

If it’s weight loss you’re after, studies have shown how bursts of high-intensity interval training are far more effective than longer, less intense workouts so mountain climbers, as part of a HIIT workout, could be the ticket to burning unwanted weight.

100 mountain climbers a day for three weeks: my verdict

Overall, doing 100 mountain climbers a day for three weeks was a useful addition to my ab workouts however they weren’t the be-all and end-all. I could happily go without them. Although I will be incorporating them into more ab and arm workouts going forward due to the muscle activating benefits I discovered.

To make them harder, I may do these mountain climbers whilst wearing a weighted vest. The added resistance will just make muscles work a little harder (which is what we want to build strong muscles), plus it would certainly cause my heart rate to increase, boosting the cardio element of the move.

If you’re looking for an easy challenge, if you’re relatively new to fitness, or simply just want an easy addition to your workouts that doesn’t require too much effort, then I definitely recommend giving this a go. You may notice other benefits that I didn’t or you may just find that it gives your core an extra minute or so of bodyweight resistance. 

For more challenges we’ve been taking on, find out what happened when we did 100 lunges a day for a month.

Lucy is a freelance journalist specializing in health, fitness and lifestyle. She was previously the Health and Fitness Editor across various women's magazines, including Woman&Home, Woman and Woman’s Own as well as Editor of Feel Good You. She has also previously written for titles including Now, Look, Cosmopolitan, GQ, Red and The Sun. 

She lives and breathes all things fitness; working out every morning with a mix of running, weights, boxing and long walks. Lucy is a Level 3 personal trainer and teaches classes at various London studios. Plus, she's pre- and post-natal trained and helps new mums get back into fitness after the birth of their baby. Lucy claims that good sleep, plenty of food and a healthy gut (seriously, it's an obsession) are the key to maintaining energy and exercising efficiently. Saying this, she's partial to many classes of champagne and tequila on the rocks whilst out with her friends.