Doing Fasted Kettlebell Swings (Pros and cons)

I love kettlebell swings and one of the easiest ways to speed you your weight loss results is to do them on the empty stomach.

Today I will explain the science and share my personal experience from doing fasted kettlebell training.

picture of empty plate without any food

One of the advantages of doing fasted kettlebell swings (exercising on empty stomach) before your meal is greater lipolysis in adipose tissue, as well as increased fat oxidation. However, having a small meal before your training can help to improve exercise performance, research suggests.

Here is my overall opinion, but if you wanna know more details about the pros and cons of doing fasted kettlebell training, keep reading.


Doing fasted kettlebell swings means training before your first meal. Exercise on empty stomach is nothing new and its been excessively studied, especially among the people who practice Ramadam.

The reason why I started doing fasted kettlebell swings is not becasue of religion, but because I was experimenting with intermittent fasting.

In their recent review article, Dr. Hassane Zouhal and Dr. Ayoub Saeidi show that intermittent fasting creates favorable changes in the body, both acute and chronic.

According to experts, IF helps with:

  • Increasing reliance on fat as an energy source;
  • Reduction in serum glucose levels; and
  • Reduction in body weight, waist circumference, and body mass index.

I love to experiment with myself (especially when it comes to exercise and nutrition.)

The 16/8 intermittent fasting protocol allows me to eat for 8 hours and don’t eat for 16. So to follow the rules, I needed to do my kettlebell workout on the empty stomach.

Benefits of fasted kettlebell swings

One of the biggest advantages of doing kettlebell training on the empty stomach is improved body composition, as long as you train at a moderate intensity.

“Exercise during fasted state has been shown to increase fat oxidation, as well as increase the activity of fat-burning enzymes,” says a physical trainer at Respiro Health and Fitness Centre, Karen Van Proeyen, Ph.D.

“Fasted exercise may improve plasma lipid profiles and helps with balancing your LDL and HDL ratio,” adds Dr. Proeyen.

“To be specific, exercise on the empty stomach can enhance the activation of molecular signaling pathways in skeletal muscle,” Dr. Proeyen explains.

In other words, if you choose to train in the morning (before your breakfast) your muscles are like a sponge for the food that you eat.

“The more often you train fasted, the more calories go to the muscle, not to the fat cells. This means muscles work as glucose disposal, which in return reduces glucose levels in the blood,” says Dr. Proeyen.

As you can see, I reached out to a number of experts and went through dozens of scientific articles over the years and every single one confirms the beneficial effects of fasted resistance training on body composition.

In fact, when it comes to improving body composition, I haven’t found a single research that would support the advantage of fed-state versus fasted-state.

So doesn’t matter how you cut it, when it comes to burning fat, fasted training is effective.


One of the downsides of doing fasted kettlebell training that I’ve noticed is that I wasn’t able to do as many reps and sets as I would normally do when training after a meal.

For example.

  • Doing 200 kettlebell swings after a meal felt relatively easy.
  • Doing 200 swings on empty stomach felt more challenging, the weight felt heavier, and I noticed an energy drop for the rest of the day.

I also noticed that I reached exhaustion much faster, compared to the fed state.

For example.

  • During fed-state, I was able to do 25 to 30 swings in one set.
  • During fast stated, I was able to only do 15 to 20 swings per set.

My point is that I needed to lower my reps and sets and overall training volume and intensity to be able to maintain my energy and do things for the rest of the day.

Research is not conclusive

The effects of exercise during the fasted state on performance are not conclusive.

Some studies have documented that fast training can improve performance, whereas others show quite the opposite.

Dr. Proeyen said, “habitual fasted training on sedentary and untrained people is a positive strategy to stimulate physiological adaptations in the muscle that could improve endurance exercise performance”.

On the contrary, the review article published in the Journal of Strength and Conditioning Research by ‪Anis Chaouachi, Ph.D., states that fasted state led to lower average power during the 30-second repeated jump test, as well as an increase in total fatigue scores.

It’s fair to say that doing fasted kettlebell swings can lower your performance, but it will depend on your workout intensity, exercise type, individual fitness level, as well as exercise duration.

Things to consider

What is the best time to do kettlebell swings? This is a great question that came to me a few days ago from one of my clients, Emily.

She really wanted to speed up her results and was considering going one step further and trying doing fasted kettlebell swings, first thing in the morning.

According to the aforementioned review article from Dr. Zouhal and Dr. Saeidi, it’s definitely something worth trying (just because of the benefits).

Whether you should be doing fasted exercise or not, there are a few things you need to take into consideration.

Training session duration

The first step is to determine how much time your typical training session takes.

“Pre-exercise feeding (which means exercise after your meal) can result in an enhanced prolonged duration of the exercise,” says Dr. Proeyen.

This means that if you plan to perform a longer session, 90-minute plus, then you be better off eating something before you work out.

“This happens because the muscles are pretty much depleted from glycogen after all-night sleep,” explains Dr. Proeyen.

On the contrary, if you plan to do a shorter session, then being in the fasted state won’t affect your performance,” Dr. Proeyen clarifies.

In other words, you can still maintain your energy levels, as long as you won’t keep your training duration too long.

Your fitness goals

Another important aspect to take into consideration is your fitness goals.

For example.

  • Maybe you use kettlebell swings to improve your 10k run.
  • Maybe you add swings to prepare for your swimming competition.
  • Maybe you train with a kettlebell to help you win the judo tournament.
  • Maybe you train to prepare for a trekking challenge in Nepal, or row through the Atlantic ocean? I’m not joking.

The perfect example of this kind of adventure is the story of Roger McCarthy, who completed 3000 miles of unsupported row across the Atlantic from La Gomera in the Canaries to Antigua in the Caribbean.

3000m row pass the Atlantic
3000 miles distance from La Gomera in the Canaries to Antigua in the Caribbean

How on earth would you train for that event? Rowing machine? Treadmill? Sit-ups? Nope.

Kettlebell swings. That was the secret sauce of Roger’s conditioning program.

So there is some power in doing kettlebell swings. In other words, what is your goal for the training session?

Fitness Level

Another thing to take into consideration before choosing the fasted vs fed exercise is your fitness level. In other words, how trained you are?

  • Are you exercising on a regular basis and you look for something new and challenging?
  • Are you just getting started or have you had a long-term break and you want to get back to shape?

Because based on that, your results will vary (significantly).

Let me explain.

  • When performing an exercise in the fasted state at a low intensity, both trained and untrained individuals will get the same results (that means the rate of fat oxidation will be similar).
  • The more training experience you have, the more you can benefit from the high-intensity training sessions.

My point is that you can do the same workout routine as someone else but see completely different results.

Some people may recommend you do fast kettlebell training because it works for them, but this won’t guarantee it will work for you.

So keep that in mind.


Another thing to keep in mind when choosing fasted vs fed kettlebell training is your lifestyle (aka the biopsychosocial model.

For example.

  • Your work environment and everything that you do at work.

If you spend 12 hours a day at work, and now you put on yourself additional stress by “fasted workouts”, it won’t be long until your cortisol levels will skyrocket.

  • Your social circle, friends, and family members.

If you stay up late or have a long night out, then fasted training won’t fix the problem. The problem is the problem.

  • Your stress levels.

If something totally stresses you out and makes you constantly think (about the problem), it becomes very difficult to stay consistent with exercise, especially early-morning fasted exercise.

  • Your sleep and circadian rhythm.

If your sleep is interrupted then you won’t get the best results.

  • Your home environment and relationships.

Ideally, you want to do fasted kettlebell swings at home. This will save you time. But if the only option is driving to the gym at 4:30 am, that’s another stress factor.

How long should I do fasted kettlebell swings training?

Remember that everyone is different and you will need to see how your body responds to fasted workouts.

For the best results,

  • I recommend starting from 20-25 minutes per training session. When you see how you feel, then you can adjust accordingly.
  • Start from 3-4 times a week.

After your fasted workout, I recommend eating meals that are high in protein and some carbohydrates to replace used-up glycogen from the muscles.


  • There are some elements that you need to consider before deciding whether doing fasted kettlebell swings is the right choice for you.
  • These include your general fitness goal, your work type and schedule, the duration of the training session, the type of workout, the weekly volume, intensity, and individual characteristics.

Michal Sieroslawski

Michal is a personal trainer and writer at Millennial Hawk. He holds a MSc in Sports and Exercise Science from the University of Central Lancashire. He is an exercise physiologist who enjoys learning about the latest trends in exercise and sports nutrition. Besides his passion for health and fitness, he loves cycling, exploring new hiking trails, and coaching youth soccer teams on weekends.

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