Flywheel Training: Secret Training Method For Ultimate Size, Strength & Power

January 27, 2022

Athletes and weekend warriors are always looking for new training methods to give them that edge. While flywheel training isn’t new, it is only recently making its way into the mainstream fitness population.

Flywheel training has resistance from inertia, whereas traditional strength training employs resistance from gravity and load. The main benefit of flywheel training is overloading the eccentric phase without special equipment or spotters.

So, how can flywheel training benefit you, and why should you use a flywheel device?

What Is Flywheel Training?

Flywheel training was initially developed for astronauts to counteract the adverse effects of low gravity and muscle loss [1]. Because flywheel technology doesn't require gravity and load, you can use it anywhere.

Since then, it has been heavily studied within the athletic and general population on Earth. A flywheel training device consists of one or more flywheels (discs) connected to a rotating shaft. This shaft has a strap or band wound to it, and when the band is pulled, the flywheels rotate.

Once the strap is pulled to its maximum length, the flywheels keep spinning the strap is rewound around the shaft. Because it doesn't rely on gravity and instead the inertia of the flywheel (I'll explain this soon), you can perform exercises in any direction depending on where the flywheel is set up.

For example, rotational core exercises, squats, or triceps extensions are exercises in multiple directions that you can load with the flywheel. So, how does a flywheel provide load?

How Does Iso-Inertial Flywheel Training Work?

What Is Flywheel Training

Flywheels deal in inertia rather than thinking in terms of absolute load (e.g., 100 lbs). If you remember physics 101 from your schooling days, or if you're a fan of Mr. Newton, you'll know that inertia is simply an object's resistance to any change in velocity.

An easy way to think about this is to picture a semi-truck, and a Mini Cooper parked next to each other on a slight downward hill. Both drivers get out of their vehicles but forget to pull the handbrake. So, they start to roll down the hill.

So, you rush in front of one of the vehicles to stop it from rolling down the hill using your surreal strength and explosive power developed on the Farm Boy Strength Program.

Which one is going to be harder to stop? The semi-truck? Or the Mini Cooper? The semi-truck, of course. Meaning it has greater inertia.

Mass plays a significant role in inertia, so increasing the load (disc size or the number of discs) requires more force to get them spinning and more force to stop them spinning, especially at speed.

Thus, for example, when doing a flywheel squat, the concentric (upward) phase transfers kinetic energy (motion) to the flywheels. Once the strap starts to wind around the shaft, it takes eccentric (lengthening) muscle action to slow the motion of the flywheels [2].

It is called iso-inertial resistance because there is constant inertia throughout the exercise, allowing maximum force at every joint angle. How is this different from traditional strength training, then?

Flywheel Training vs. Traditional Strength Training

Flywheel Training vs. Traditional Strength Training

There are key differences between flywheel and traditional strength training. The first I've explained above is where traditional strength training relies on load and gravity for resistance.

In contrast, flywheels rely on inertia to be performed in any direction. Traditional strength training with the barbell only works in vertical movement in line with gravity.

The second difference is the type of muscle contraction. Traditional strength training is known as isotonic, where the resistance is constant throughout the eccentric and concentric phases.

Based on the length-tension relationship of muscle, you will be well experienced in knowing that you are much stronger in the top half of the squat compared to the bottom half.

Simply put, there are optimum joint angles where you can produce peak torque (rotational force) [3]. This means that certain ranges of motion are "easier" than others during an exercise.

Hence, you fail squats a quarter way up as the bottom range is the hardest, and the muscles are at their longest lengths. And you never fail once you get past halfway.

The same example can be applied to the bench press. The pecs are fully stretched in the bottom position. Still, they are at their optimum length to produce maximum force approximately halfway up.

Flywheel training takes advantage of inertia. So instead of having “easier” parts of an exercise, you have equal tension throughout the entire range of motion.

Meaning you can produce maximum force at any point in the range of motion. Further, the resistance provided by the flywheel is matched to the effort placed during the concentric phase.

So, how hard you push or pull during the muscle shortening phase of an exercise (e.g., pushing up with a squat) is how much resistance you will get on the downward or eccentric phase of the exercise (more on this to come).

But these aren't the only differences between flywheel and traditional strength training. There are many benefits to using a flywheel that apply to various people.

Benefits Of Flywheel Training

Benefits Of Flywheel Training

Accentuate The Eccentric

Accentuating the eccentric or eccentric overload is the primary use for flywheel training. True eccentric exercise (click for an in-depth breakdown) requires using loads or resistance that is greater than can be handled during the concentric phase [4].

This is due to being 20-50% stronger during eccentric contractions than concentric [5]. So even if you are squatting using your 1RM, you are training the eccentric contraction sub-maximally.

Doing eccentric exercise with traditional strength training requires extra equipment and potentially training partners for safety. For example, adding weight releasers to the barbell to overload the eccentric portion of the exercise.

If you've ever failed a lift on the first rep because the weight was too heavy, technically, you performed an eccentric exercise as a crude example.

The flywheel allows you to overload the eccentric phase with ease and target different portions of the range of motion [6]. For example, concentrating on resisting the flywheels midway or at the bottom range of the squat.

Variable Resistance

I explained earlier that the resistance provided by the flywheel matches the effort you put in during the concentric phase. As in, the downward pull matches the upward drive. This is called variable resistance.

If you drive upwards maximally for every rep, you have a higher maximum force and power output from the first rep. Traditional strength training is only maximal at the last rep at failure, and all reps before that are submaximal. For example, squatting 80% 1RM for a set of 8 reps, reps 1 to 7 are sub-maximal.

Further, as you fatigue with the flywheel, the resistance level follows as it is dictated by the concentric effort, making it a safe alternative to traditional strength training.

Reduce The Risk Of Injury

Eccentric exercise to reduce the risk of injury has been studied extensively with significant effects [7]. The flywheel is no different. A study in elite soccer players found flywheel lying leg curls done every 4-5 days for a total of 16 sessions, using 4 x 8 with 1 min rest significantly lowered hamstring injuries throughout the season [8].

Players were instructed to resist the last half of the eccentric range of motion after a maximal concentric effort to target the eccentric overload at longer muscle lengths.

Elite junior soccer players saw a reduction in injury severity when using the flywheel leg curl and squat for ten weeks [9]. Bear in mind that this was compared to no strength training.

Higher Rep Ranges

Flywheel training allows you to train in the higher rep ranges with greater force and power outputs than traditional strength training.


Best Flywheel Training Device

Depending on the flywheel device, they are extremely portable. In fact, New Zealand Athletics will travel around the world with their flywheel devices to continue their training program in any gym.

They are small enough to pack into a suitcase (depending on the brand) and even use in your living room without taking up much space.

Increase Strength, Power, And Muscle Mass

Flywheel training is excellent for packing on muscle mass, increasing strength, and becoming more powerful. While not statistically significant, this study found the flywheel group doubled their muscle growth compared to the machine group [10].

A recent meta-analysis (combining all relevant studies into one extensive study) shows you can expect approximately a 7-8% increase in muscle size after 5-8 weeks of flywheel training 2-3 times per week [2].

You can expect to potentially see approximately a 17.3% increase in strength after 4-10 weeks of flywheel training 1-3 times per week [2]. Finally, you may see approximately a 25.2% increase in power after 4-24 weeks of flywheel training 1-3 times per week [2].

Who Should Use Flywheel Training?

Flywheel training is versatile enough to be used by a wide range of individuals. But it might be better for some compared to others.

Intermediate To Advanced Athletes

Beginners and untrained individuals don't seem to benefit from flywheel training as intermediate to advanced athletes do [2]. That doesn’t mean beginners don’t benefit at all, but they may be better served performing traditional strength training to build a base level of strength before attacking flywheel training.

Older Adults

While younger individuals (<39 years old) seem to see more significant benefits from flywheel training than older individuals (>59 years old) [2], the few published research papers show flywheel training can enhance muscle strength, power, mobility, and balance in older individuals [12].

The best thing is how safe flywheel training is. Because the resistance is only equal to the force you generate, the forces are also reduced as you fatigue and slow down. Unlike the barbell, the resistance remains the same when you fatigue, which can be difficult for older adults to handle.

How To Use Flywheel Training?

I’ve taken these techniques from Cody Roberts, a strength and conditioning coach from the University of Iowa. He is a flywheel training genius, so make sure to give him a follow.

Delayed Braking Action

Eccentric overload is achieved most commonly through a delayed braking action. As I demonstrate in the above video, you want to resist maximally near the end of the movement. In the squat example in the video, I ride the flywheel down, and then at the last minute, I'll try to stop the flywheel with maximum force.

This eccentrically overloads the end range as you’re trying to stop movement in a short period. The peak eccentric forces generated are massive.

Impulse Overload

Impulse overload involves positioning yourself in the eccentric phase, so the load hits you, and you need to stop it. You can see in the video how I position myself in a half squat and let the weight hit me, and I need to be able to quickly brake eccentrically.

Concentric Overload

The forces required to stop the flywheel during the eccentric is dictated by how fast you can move the flywheel concentrically. If you can overload the speed during the concentric, you will have a more brutal eccentric phase.

By holding onto something in front of you and pushing against it, so your upper body is involved on the concentric, you can generate extra force than with just your legs. Now you have overloaded the eccentric phase as you are braking without your arms.

Movement Assisted Concentric Overload

This is another way to overload the concentric, using a movement where you are strongest during the concentric and an exercise where you're weaker in the eccentric. The example in the video involves a deadlift during the concentric and a Romanian deadlift during the eccentric.

2 Up, 1 Down

Two up, one down is a strategy often used with machine-based training. For example, the lying leg curl. By using two legs to lift the weight, you can use heavier loads. Resisting on the way down with one leg eccentrically overloads the working muscles.

My video example is a two-legged squat on the concentric and a one-legged squat on the eccentric phase.


Priming exercise takes advantage of the post-activation potentiation phenomenon. That is performing a pre-conditioning exercise (usually a heavy, high force exercise like a squat) followed by a high-velocity power exercise (like a jump) [13].

But the pre-conditioning exercise isn't limited to heavy barbell movements. The flywheel has been shown to enhance jump height 3-9 minutes after 3 x 6 flywheel half squats [14]. Similar findings are seen after 1 x 5 flywheel "swim starts," enhancing vertical force production [15].

Considering there is little difference between using the flywheel or barbell for priming exercise [16], you should consider the flywheel for use before activities or competitions where barbells and weights are not available.

Further, from an anecdotal perspective, 5-6 maximal reps on the flywheel are far less fatiguing than performing a heavy barbell exercise. You can also get creative and perform overcoming isometrics as a potentiation exercise, as demonstrated below.

How Many Flywheel Discs Should You Use?

The research uses 0.07 to 0.145 kg.m2, which is the degree of inertia [2]. Within the athletic population, 0.05 to 0.11 kg.m2 has been shown to improve athletic performance [11]. How many discs is this?

Exerfly (more on this in them in the next section) has listed the inertia of each flywheel disc they have. It goes like this:

  • Small yellow flywheel – 0.01
  • Large yellow flywheel – 0.025
  • Blue flywheel – 0.05
  • Red flywheel – 0.1

As you can see, having one of each disc allows you to work between the current recommended inertia ranges. Generally, you will use greater inertia when targeting force capabilities and lower inertia when developing power.

Recommended Flywheel Training Equipment

You cannot go wrong with Exerfly due to their wide range of flywheel devices. They have a large platform that you can set up with a bench for bench pressing, a portable platform for traveling or smaller home gyms, and a rack mount attached to your power rack for more versatile movement.

You can read my full Exerfly review here.

Use code "LBEB" at checkout for 2% OFF any purchase.

But what sets Exerfly over other competitors is their Eccentric Max function. This function allows you to overload the eccentric phase with a motor.

While it's hard to see it in action in this video, I have the eccentric motor set to pull 10% harder than I pull concentrically. It can go all the way to 80%! Don't sleep on this function for those looking to develop ridiculous speed and power.

You can also track force, velocity, power, and rate of force development metrics within the Exerfly app so you can have data to track your progress. If you’re looking for a piece of training equipment for your garage gym, then look no further than the Exerfly.

As you can see, I’m using the equipment within a garage. They don’t take up much space and are so versatile you can get a full workout without the need for other equipment. For example, the platform comes with a bench to train upper body exercises.

You can also perform lateral exercises like lateral lunges, rowing movements for your back, and even hip thrusts. You can check out the Exerfly platform below:

Exerfly Platform For Flywheel Training

What many people like to do, though, is purchase the portable Exerfly as the middle piece can also be used as a rack-mount, giving you multiple training options with one piece of equipment. The portable Exerfly is excellent as it can be easily assembled or taken apart when traveling or needing to move it around.

It is best used for large staple training movements like squats and deadlifts. But you're not limited to these with various biceps curls and shoulder pressing variations.

Exerfly Portable For Flywheel Training

Finally, the rack mount excites me to no end as performing rotational exercises becomes a breeze.

The inherent issue when performing rotations with cables or bands is that movement becomes easy either near the beginning or end. With the flywheel, you have constant resistance eccentrically that you have to resist.

When it comes to grappling or collision sports, this type of strength training will transfer to manipulating other human beings.

Exerfly Rack Mount For Flywheel Training

If you're wondering how many flywheel discs you'll need, here is what I would recommend starting with:

  • 2 x red (0.1 inertia)
  • 1 x blue (0.05 inertia)
  • 1 x large yellow (0.025 inertia)
  • 1 x small yellow (0.01 inertia)

The small discs are usual for prehab or rehab-type exercises like external shoulder rotations. This will give you more than enough resistance to work from, and if you need extra, you can stack more red discs.

Use code "LBEB" at checkout for a FREE red flywheel disc with any purchase.


Flywheel training is a unique method of strength training that is safe and effective for enhancing strength, power, and hypertrophy. Its main advantage is overloading the eccentric phase, which is challenging with traditional strength training. The benefits from eccentric training are too good to ignore, especially for athletic performance.


1. Berg, H. E., & Tesch, A. (1994). A gravity-independent ergometer to be used for resistance training in space. Aviation, space, and environmental medicine, 65(8), 752-756.

2. Petré, H., Wernstål, F., & Mattsson, C. M. (2018). Effects of flywheel training on strength-related variables: A meta-analysis. Sports medicine-open, 4(1), 1-15.

3. Brughelli, M., & Cronin, J. (2007). Altering the length-tension relationship with eccentric exercise. Sports Medicine, 37(9), 807-826.

4. Douglas, J., Pearson, S., Ross, A., & McGuigan, M. (2017). Chronic adaptations to eccentric training: a systematic review. Sports Medicine, 47(5), 917-941.

5. Bamman, M. M., Shipp, J. R., Jiang, J., Gower, B. A., Hunter, G. R., Goodman, A., ... & Urban, R. J. (2001). Mechanical load increases muscle IGF-I and androgen receptor mRNA concentrations in humans. American journal of physiology-endocrinology and metabolism, 280(3), E383-E390.

6. Norrbrand, L., Pozzo, M., & Tesch, P. A. (2010). Flywheel resistance training calls for greater eccentric muscle activation than weight training. European journal of applied physiology, 110(5), 997-1005.

7. Brughelli, M., Nosaka, K., & Cronin, J. (2009). Application of eccentric exercise on an Australian Rules football player with recurrent hamstring injuries. Physical Therapy in Sport, 10(2), 75-80.

8. Askling, C., Karlsson, J., & Thorstensson, A. (2003). Hamstring injury occurrence in elite soccer players after preseason strength training with eccentric overload. Scandinavian journal of medicine & science in sports, 13(4), 244-250.

9. de Hoyo, M., Pozzo, M., Sañudo, B., Carrasco, L., Gonzalo-Skok, O., Domínguez-Cobo, S., & Morán-Camacho, E. (2015). Effects of a 10-week in-season eccentric-overload training program on muscle-injury prevention and performance in junior elite soccer players. International journal of sports physiology and performance, 10(1), 46-52.

10. Norrbrand, L., Fluckey, J. D., Pozzo, M., & Tesch, P. A. (2008). Resistance training using eccentric overload induces early adaptations in skeletal muscle size. European journal of applied physiology, 102(3), 271-281.

11. Beato, M., & Dello Iacono, A. (2020). Implementing flywheel (isoinertial) exercise in strength training: current evidence, practical recommendations, and future directions. Frontiers in physiology, 11, 569.

12. Kowalchuk, K., & Butcher, S. (2019). Eccentric Overload Flywheel Training in Older Adults. Journal of Functional Morphology and Kinesiology, 4(3), 61.

13. Seitz, L. B., & Haff, G. G. (2016). Factors modulating post-activation potentiation of jump, sprint, throw, and upper-body ballistic performances: A systematic review with meta-analysis. Sports medicine, 46(2), 231-240.

14. Beato, M., Stiff, A., & Coratella, G. (2021). Effects of postactivation potentiation after an eccentric overload bout on countermovement jump and lower-limb muscle strength. The Journal of Strength & Conditioning Research, 35(7), 1825-1832.

15. Cuenca-Fernández, F., López-Contreras, G., Mourão, L., de Jesus, K., de Jesus, K., Zacca, R., ... & Arellano, R. (2019). Eccentric flywheel post-activation potentiation influences swimming start performance kinetics. Journal of sports sciences, 37(4), 443-451.

16. Beato, M., Bigby, A. E., De Keijzer, K. L., Nakamura, F. Y., Coratella, G., & McErlain-Naylor, S. A. (2019). Post-activation potentiation effect of eccentric overload and traditional weightlifting exercise on jumping and sprinting performance in male athletes. PLoS One, 14(9), e0222466.

About the Author

I am a professional strength & conditioning coach that works with professional and international teams and athletes. I am a published scientific researcher and have completed my Masters in Sport & Exercise Science. I've combined my knowledge of research and experience to bring you the most practical bites to be applied to your training.

Want More Great Content?

Check Out These Articles