Flywheel Training – tips and tricks
Part 1: Kettlebell vs Flywheel Training explained in detail (5min)
Part 2: How to achieve eccentric overload (2 min)
Part 3: What are the results when you don’t train eccentric overload (1min)
Part 1: Kettlebell vs Flywheel Training explained in detail (5min):
Muscles are by nature: stronger in the eccentric phase – than in the concentric phase!
At traditional squats (with or without added gravity like kettlebells or barbells) you have concentric overload instead of eccentric overload which is contradictory to your natural muscle strength distribution.
Train your eccentric phase with your STREXBOX!
Flywheel training comes closest to your natural muscle strength distribution by enabling you to train with eccentric overload.
This means your 1 repetition maximum (1 RM) is higher in the eccentric phase than the concentric phase by nature. This means you are far away from training your 1RM eccentric phase when you train with traditional weights because it only triggers your 1 RM concentric phase, therefore you lose significant training success. To optimize your training, you should train with less weight on the concentric phase and more weight on the eccentric phase. This is called “eccentric overload”. This can be easily achieved with the STREXBOX.
Kettlebell eccentric:
Kettlebell or barbells or just squats without additional weights in general have their peak eccentric force (red circle) in the eccentric phase (red marked lines) right before your athlete stops in the deepest squat position. Why at this point?
Max eccentric force = gravitational force + deceleration force of the kettlebell
The deceleration force of the kettlebell can be viewed as if you would catch a falling kettlebell. You have to stop the downward movement of the kettlebell at the deepest point which results in an increased deceleration force and leads to max eccentric force (red circle).
At the beginning of the eccentric phase when you are standing upright, the force is less which is shown in a decrease in force in the force-time-chart on the red line (eccentric phase) because you move your body weight and the kettlebell weight towards the gravity of the earth. As you know all objects fall on the floor when you drop it (unless you are on planet earth and not outer space).
That also explains why the average eccentric force (move downwards toward gravity) is less than the average concentric phase (move upwards against gravity).
As we have learned above, your muscle are by nature stronger on the eccentric side than the concentric side, therefore gravity based squats cannot unleash your full training potential.
Kettlebell concentric:
Kettlebell or barbells or just squats without additional weights in general have their peak concentric force (green circle) in the eccentric phase (green marked lines) slightly after your athlete moves from the deepest squat position upwards.
Max concentric force = gravitational force + acceleration force of the kettlebell against gravity
The acceleration force of the kettlebell creates the peak concentric force (green circle). That means furthermore that the faster the kettlebell and your body is accelerated upwards against gravity the higher is your max concentric force. This concentric peak is usually around +30%.
Summary Kettlebell:
Kettlebells and barbells have a low +-30% force variation.
The eccentric phase has lower average forces than the concentric phase.
Flywheel eccentric:
With a flywheel you can achieve up to +75% eccentric overload.
The eccentric phase starts when you are at your highest squat point. At this point the flywheel spins at its maximum speed. If you have chosen the length of your pull belt correctly, which is slightly longer than your highest squat point, then there is no force for a split second on the pull belt at your highest squat position, that is the beginning of the red line in the force-time-chart.
When you then go downwards you have to actively decelerate the flywheel from spinning fast to zero, flywheel standing still when you reach your lowest squat point. The less time you need to decelerate the flywheel while going downwards the higher the max eccentric peak force will be.
Flywheel concentric:
At the beginning of the concentric phase, which is the beginning of the green line in the force-time-chart, which furthermore is your deepest squat position, is also your peak concentric force (green circle). While going up you accelerate the flywheel, the faster you go up, the higher your concentric peak force will be. When you reach your highest squat point the concentric force will become zero, because there will be a split-second no load on the pull belt.
As you see you can achieve with a flywheel device much higher peak eccentric forces and also higher average eccentric forces then concentric forces.
As have learned above, your muscle are by nature stronger on the eccentric side than the concentric side, therefore flywheel training comes closed to your natural muscle force distribution and helps to unleash your full training potential.
You wonder where the force-time-charts come from? Recorded with our Powermeter force sensor!
Summary Flywheel:
A flywheel can produce in the eccentric phase higher average forces and higher peak forces than in the concentric phase and up to 175% force variation in the eccentric phase.
Bonus: Let´s look at another example.
U.S. pro skier Brian Mc Laughlin performing explosive squats on the STREXBOX and we measured his forces with our Powermeter.
In the next chapter below How to achieve ECCENTRIC OVERLOAD you will learn how to influence the eccentric overload rate and force patterns with the athlete’s active acceleration and deceleration timing. But first take a look at Brian. Brian performs his repetitions with 10% to 30% eccentric overload. Brian goes very hard on the concentric side to achieve high peak concentric forces and also focuses on decelerating the flywheel aggressively right when the eccentric phase starts which leads peak eccentric forces higher than the peak concentric forces and to a medium eccentric overload between 10% to 30% in his repetitions.
Part 2: How to achieve eccentric overload (2 min)
Eccentric overload as well as concentric overload is possible with a flywheel device, determined by the pulling pattern of your athlete:
A flywheel device is isoinertial. That means the inertia of the flywheels does not change at any time. This allows to use the athletes maximum muscle power in each angle, theoretically. As we said above the muscles are by nature stronger in the eccentric phase than the concentric phase. That means the optimum muscle load is characterized by eccentric overload.
How to achieve eccentric overload:
Option 1: Athletes pulls with constant force for a long period of time when he stretches his legs in the concentric phase to accelerate the flywheel and avoid any concentric force peaks. When the athletes enters the eccentric phase when he goes down into squat position, the athlete decelerates the flywheel in a short period of time leading to high eccentric peak forces and eccentric overload.
Option 2: Athlete pulls in the concentric phase with arms and legs with the help of our Eccentric Overload Aid (can be bought in the online shop as accessory) to accelerate the flywheel. When the athletes enters the eccentric phase when he goes down into squat position, the athlete decelerates the flywheel only with his legs or just with minimal support from his arms. Long and short period timing is here not that important, meaning with the Eccentric Overload Aid you have a longer eccentric phase duration and more control about the actual eccentric load you can achieve.
Popular mistakes: Especially when the athlete is in the deep squat position and starts to accelerate the flywheels at the beginning of the concentric phase, most athletes pull much too hard. At the same time the athletes often pull not strong enough at the end of the concentric movement. A constant pull during the concentric phase is optimal to perfectly preload the flywheel for the eccentric overload period. When the eccentric phase starts, that means when the flywheel is fully spinning and the athlete starts to go down from the highest squat position, the athlete should be mentally prepared and actively brake the flywheel within a short period of time. The shorter the period of time and the harder the athletes can reduce the spinning power of the flywheel, the stronger the eccentric peak force will be compared to the concentric peak force.
Brian´s video adjustments:
Let us discuss some options how to alternate the force pattern on the example of Brian´s video above.
Increase eccentric overload by keeping the some concentric force: Increase the amount and size of inertia plates and pull more slowly in the concentric phase especially at the beginning of the concentric phase. Then explosively decelerate the flywheel at the beginning of the eccentric phase.
Increase both eccentric and concentric force: increase the amount and size of inertia plates and pull faster on the concentric side as well as the eccentric side. The faster you pull on the concentric side, the higher the peak force on the concentric side. The faster you decelerate on the eccentric side, the higher the peak force on the eccentric side.
Same as above said works for reducing force, just using less heavy inertia plates and pull more slowly in your desired phase.
Bonus: How to achieve concentric overload:
Athletes pulls hard for a short period of time in the concentric phase, at a squat this means while he goes up. In the eccentric phase the athlete then decelerates the power of the flywheels constantly to avoid any eccentric force peaks. Eccentric power could be further reduced by adding a fitness equalizer or stool as described above to absorb the remaining eccentric energy.
Part 3: What are the results when you don’t train eccentric overload (1min)
- You are missing out coming close your 1 repetition maximum of your eccentric phase and lose training success
- You increase the risk of injuries
- You limit your maximum drop set
- You miss opportunities for increasing your sprint, jump and muscle strength
It is not only injuries, often swelling, stiffness and loss in muscle force are negative impacts of skipping eccentric overload training. Above symptoms are typical for “Delayed-Onset Muscular Soreness” (DOMS), muscle damage and delayed pain due to unaccustomed eccentric loads, often while sprinting and jumping.
Up to now the best preventive strategy to avoid DOMS are repeating eccentric contraction sessions with submaximal – that means eccentric workouts below the athlete´s maximum. The eccentric contraction´s intensity should progressively increase during the workout!1
1 Hody S, Croisier JL, Bury T, Rogister B, Leprince P. Eccentric Muscle Contractions: Risks and Benefits. 03 May 2019
Maximum drop set – extend your workout
With traditional weights or body weight your last repetition before failure is maximal if you continue until failure. But could you do 3 more repetitions with let´s say 80% of your body weight? Probably yes. But you cannot lower your body weight during the squat or alternatively change the additional weight plates which creates a break and makes it impossible to gradually lower the force after you have reached your last repetition before failure with traditional weights or body weight.
With STREXBOX your maximal set is really the maximal drop set. With STREXBOX you can continue after you would have reached your last repetition before failure on traditional weights with let´s say 80% or whatever you still have left inside of you until you finally drop.
Yes, I would love to get a STREXBOX Flywheel Training Equipment:
No, I need more info:
No, I have a question:
No, this is probably not for me, because I am already at the best performance level of my life and do eccentric overload workouts everyday – okay fair enough.