How to choose your flywheel training device

As flywheel training is becoming more popular, people have also begun to realize that different flywheel devices come with different specifications. This guide will help you with your choice while avoiding any pitfalls, which could ultimately restrict your training experience.


Key points:

    • Low friction is key for eccentric load and overload
    • Low weight is important for the traveling athlete or coach
    • Stackability is beneficial for multi-system users like gyms and performance facilities
    • Inertia range is important and even weaker subjects might need high inertia in specific situations.
    • Interface to a feedback system is crucial for motivation, monitoring and follow up.
    • Range of motion is important both in lower and upper body exercises.
    • Community that comes with the brand you select can be a powerful ally.
    • Service, customer support, warranty is easy to forget, so check beforehand and ask around.

Getting a Flywheel Device

A flywheel device is probably the best purchase you can make if you already have a decent setup. Allowing for eccentric overload and a resistance type with proven robust and fast gains in strength, that also translates into performance, is key for many consumers in the athletic field. The safety, therelativelye short and steep learning curve and ergonomy is great in physiotherapy, training seniors or developing athletes. The efficacy and higher return on invested time is a game changer when it comes to health and fitness, both for gym-goers and home users. The easy part is to realize that a flywheel training device can solve many of the problems or obstacles you see in training. However, the hard part is how to choose which device to get.

To help you I’ve compiled a list of features that you should look into. Looking “under the hood” can be difficult if you are testing a device. You might come across a nice looking design with a fairly reasonable price and the training feels good on your fist attempt but what is there to consider before committing to a purchase? Here are a few factors worth considering if you want to end up being fulfilled by the device you get. As you will notice, I don’t bring up design or price since this is personal and depends on your taste and size of your wallet. If you aren’t sure about the price, look around for other devices to get an understanding of the different price points. Most serious producers have their price listed on their website.

HORIZONTAL OR VERTICAL DEVICE

To me this is a rather easy question to answer since this is not a conflict. There are many good vertically orientated exercises (pulls, squats, deadlifts, curls) and while there may not be as many horizontally orientated exercises there are still some very important ones such as rotations and shoulder exercises. So if you like flywheel training you might consider getting both types of devices. However, it’s worth noting that overload studies haven’t been done on any horizontal devices due to the higher level of difficulty when creating overload with them. The conic variations are also high speed – low force so they might be good for some explosive movements and metabolic training but maybe not as good for traditional strength. You are also limited since the limiting power output is how much force you can generate or absorb without being pulled into the device (compare lat pull if you can’t fixate your legs, at BW lifts you start lifting yourself instead and not the weight). Decide which exercises and type of load is most important for you and go with that device to start with. If you like flywheel training consider getting the other device too.

Range of motion

A range of motion is something that is easy to miss, even if you test the device. In this aspect, you have to consider both the highest top position and the lowest bottom position. Let’s start with the top position. In a demo, you might be shown a squat and then try a squat and some RDLs and you don’t realize the range of motion might be restricted to the waist area, so all upper body exercises are out of the question. Missing out on curls, pulls, rows with a low top position can be a huge drawback when you want to incorporate flywheel training into your programming.

When it comes to bottom position, a few devices have the shaft positioned on top of the foot placement area, which means these devices lose a lot of depth in the squat if you compare with a device where the shaft is placed underneath the platform for example. If you want to be doing squats lower than 90 degrees I suggest you start looking at the units with shaft placement under the platform. You can also take a look at the pulley that the device uses for connection to the belt, harness or grip. Some of these pulleys are rather big and also take away a lot of the range of motion in the depth. Make sure you can squat without the pulley interfering with your legs or your depth before you go ahead.

Friction

This is something most people don’t realize is important, which is also true for some of the manufacturers, unfortunately. Friction creates resistance, which means it will add load in the concentric phase and decrease load in the eccentric phase. A high degree of friction will make the eccentric action underloaded. Even a small increase in friction can have an impact on your training and adaptation. For example, 5% friction means that 5% of the power output will become heat. Then on the way down another 5% disappears, so in the end, you are only absorbing about 90% of the load or energy you put in during the concentric phase. With 15% friction, the eccentric phase is underloaded with about 30%. Then one of the main reasons for using a flywheel device is eliminated.

Friction may accumulate due to the quality of the device’s ball bearings or the drive belt/wire used. A very stiff belt or wire will create resistance since it will resist being rolled up more. To test the bearings, disconnect the belt or wire around the shaft, attach a flywheel and start spinning it. If the speed is very gradually reduced and it continues to rotate at a very low speed at the end, the level of friction is fairly low. A hard and distinct stop at the end probably means there is significant friction.

Another issue around friction is the data assessment from the training. Most devices measure rotation, so you only see what energy goes into and out of the flywheel rotation. This means friction will make the concentric workload look smaller (more work needed for same acceleration) and the eccentric workload will look bigger than it actually is (less work needed to decelerate the flywheel since friction ‘helps’).

Inertia range

Training in the strength-power spectrum for a normal user doing leg exercises might not require a very wide range of inertia. However, when working smaller muscle groups, doing unilateral drills or for special populations like seniors, a really low inertia can be necessary. On the other side of the spectrum for rehab and stronger athletes, a much higher inertia is needed for heavy slow resistance training in tendinopathies or for max strength and overload in regular RT. If you just can fit an additional flywheel that is good and you can order that one when you need it. However, in some devices, the possibility to change to another flywheel or add multiple flywheels might not exist. Check the available inertia levels on the device beforehand in order not to limit your use of the device.

Weight and dimensions

The material, density and design set the weight, which is an obvious restriction if you want a device than you can move around or bring with you. When it comes to storage, some devices could also be stackable which means they require very little space when they are not being used. A set of multiple systems with heavy devices that aren’t stackable would end up demanding a lot of permanent space in a gym, basically its own room, while a lighter, stackable device can be moved around and brought out when needed. And the range when it comes to weight is huge, some could be as light as 12 kg (26 lbs) while others with the same basic functionality could weight over 150 kg (330 lbs). Furthermore, a heavy device may also restrict the possibility of support, where a light device can be returned and repaired more easily. The heavier device would most likely call for an on-sight technician. Ask beforehand how the manufacturer deals with these issues, so you avoid any surprises later.

Feedback system

A good feedback system can be a very simple tool just showing power in-real time or more advanced functions and databases, depending on what you need. For all subjects, patients, athletes, weekend warriors alike, the impact on motivation and intensity is huge with a functioning feedback system. However, don’t get too hypnotized with all the features and functions you are being shown and be sure to decide first which metrics are important for you and what you’ll actually use the app for and with who. What you have to consider is the additional cost of the feedback system. Some require to be run on a laptop for example, which that might add cost and complexity to your system compared against an app for a tablet or smartphone. Some feedback systems may lock you up with subscriptions and additional costs, so this can also be verified prior committing. Some systems still use cables, which is beneficial in environments with a lot of interference but in all other cases, it’s probably more problematic.

Practical

When being demonstrated, a device it always looks very simple but do not fall for the demo tricks, you should try it for yourself and ask to test different exercises.  This will give you a chance to observe the setup and transitions on this particular device (i.e. changing flywheels, the range of motion or switching between accessories such as grips, bars or harnesses and etc). Operation is very important in the day to day work.

Some devices have the flywheels fixed with a screw and some with a quick lock. With everyday use, you can understand that you will experience a big difference between those setups. Having to lean down to reach a rope to adjust the height might not be a problem during a demo but you might realize very soon that this is troublesome in the daily practice and some of your users might find it really hard to do by themselves too. Stackability is a good feature for anyone with multiple systems, which was also brought up under ‘WEIGHT AND DIMENSIONS’ above.

Another issue is noise. Many demos are being done in noisy environments like exhibitions and you might not realize that some of these devices are almost silent and some quite noisy until you get them into your own facility.

Accessories

Most manufacturers offer their own accessories. However, if you already own a favorite bar or grip that you would prefer to continue using with your new flywheel training device, you should also check the device’s compatibility with foreign accessories, so that you aren’t restricted only to the manufacturer’s items. Since the accessories are the interface between the device and the user, they can affect the overall feeling to a large extent. A good quality bar, grip or harness that fits well can all be important factors when it comes to justifying your decision to purchase the device. If you deem it critical to be able to purchase everything simultaneously, then make sure the key accessories you need are included with the device you’re considering before you complete the order. See if you can also spot any sneaky business strategies from the manufacturer, who might try to bring down the price point on the device itself while adding quite a bit of margin on the accessories instead. So compare prices versus similar accessories with other suppliers if you don’t want to end up with a higher total cost for a lower cost device.

Community

The community is important if you want to be an early adopter and innovator in your field. The relationship between user and trainer experience from other professionals in the field can be a great asset. How is the manufacturer’s network locally, regionally and globally? And are there any other professionals you can discuss training within that community? Since all devices and their feedback software are slightly different you probably need to find users of your particular device to really benefit from their experience.

Service & customer support

Some manufacturers may be local but offer their product globally, meaning they might not be able to efficiently help you due to time zone differences or language proficiency with customer support. First, take a glance at the material they publish online, is there enough there to get you started? If not, contact them and see if they are able to provide you with more or willing to discuss more educational material so you don’t end up disappointed. Existing customers are the best judges when it comes to their level of customer support. If possible reaching out to an existing customer and ask about how their experience has been. If you can’t find a user for a specific device, are you sure you want to be the first?

So I hope this checklist will bring you confidence when you are looking to Invest in first flywheel training device. Now get out there and make a good deal and enjoy the benefits of flywheel training. Whatever product you do end up choosing, make sure to stay tuned here for the latest in flywheel training research and practises, all flywheelers are welcome! Remember, as much as you can be restricted by a device not offering the functions you need, if you don’t keep up with the latest scientific findings, you will be restricted by your knowledge when utilizing your new tool.

Happy DOMS!

/Fredrik Correa, M.D., co-founder

For further reading on the scientific support for flywheel training, look here.

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