Flywheel Training- The Key to Stronger Hamstrings and Injury Prevention in Athletes

Hello Coaches,

Flywheel training, also known as flywheel resistance training or inertia flywheel, is transforming the way athletes enhance performance and prevent injuries. By leveraging eccentric flywheel exercises and flywheel workout machines, this innovative method strengthens the hamstrings and improves eccentric movement, making it ideal for sports performance and rehabilitation.

The Hamstrings and Their Importance in Sports Performance

The hamstrings are a group of muscles located at the back of the thigh, comprising three main muscles: the biceps femoris, the semitendinosus, and the semimembranosus. These muscles play a crucial role in:

1. Knee flexion and hip extension.
2. Pelvic stabilization during movement.
3. Eccentric control during high-speed activities, such as running, changing direction, and decelerating.

Because of these critical functions, the hamstrings are highly susceptible to injuries, especially in high-intensity sports like soccer, track and field, and rugby. Hamstring injuries account for 12% to 16% of all muscle injuries in professional sports.

One of the most important factors in preventing these injuries is improving eccentric strength and fascicle length, which is where flywheel training stands out.

What is Flywheel Training and How Does It Work?

Flywheel training uses an inertial resistance system generated by a rotating disc (flywheel). Unlike traditional weights, where resistance is dependent on gravity, the flywheel’s resistance is proportional to the force the athlete applies. This means:

• During the concentric phase, the athlete propels the disc forward.
• In the eccentric phase, the disc returns the stored energy, requiring the athlete to control the movement as the muscle lengthens.

This principle allows for continuous eccentric overload, maximizing muscular stimulus, which is not always achievable with traditional weights.

Specific Benefits of Flywheel Training for the Hamstrings

1. Enhanced Eccentric Strength
   Flywheel training provides constant resistance during the eccentric phase, forcing the muscles to control the load more effectively. This not only strengthens the hamstrings but also prepares them to withstand the forces encountered during sprints and decelerations.
2. Increased Fascicle Length
   Studies have shown that flywheel training significantly increases the fascicle length of the biceps femoris, a key factor in reducing injury risk. For example:
   • In a 6-week study, a 14% increase in fascicle length was observed following flywheel training, while traditional methods showed no significant changes.
3. Transfer to Sports Performance
   Flywheel training improves key parameters such as horizontal force and maximum speed. This is especially beneficial for sports that require quick changes of direction, accelerations, and sprints.
4. Injury Prevention
   Thanks to its unique muscular adaptations and eccentric strengthening, flywheel training significantly reduces the incidence of hamstring injuries. It is also an excellent tool for athletes recovering from injuries to progressively and safely regain strength.

Scientific Foundations of Flywheel Training

The effectiveness of flywheel training is supported by numerous scientific studies. Here are some key findings:

• Eccentric Strength and Performance: Research shows that athletes with higher levels of eccentric strength in the hamstrings are less likely to get injured. For every 10 N increase in eccentric strength, the risk of injury decreases by 8.9%.
• Muscle Architecture: Short fascicle lengths in the biceps femoris are a known risk factor for injuries. Flywheel training has proven to be more effective than traditional exercises in increasing fascicle length.
• Comparison with Other Methods: Electromyographic studies comparing flywheel training with exercises like the Nordic Hamstring Curl show that while both are effective, flywheel training allows for greater load individualization and produces less initial fatigue, making it more suitable for progressive programs.

How to Implement Flywheel Training

1. Key Exercises to Include

• Flywheel Leg Curl: Ideal for targeting eccentric strength in the biceps femoris and semitendinosus.
• Hip Extension: Focuses on functional patterns that directly transfer to sports movements.
• Flywheel Hip Thrust: Targets hip stability and explosive power.

2. Frequency and Volume

• Frequency: 2-3 times per week.
• Repetitions and Sets: Perform 3-4 sets of 6-8 repetitions, focusing on a controlled eccentric phase.
• Progression: Start with a low inertia to familiarize the athlete and progressively increase as they adapt.

3. Familiarization Phase
   Flywheel training requires precise technique to maximize its benefits and avoid injuries. Dedicate the first 2-3 sessions to familiarizing athletes with the equipment, ensuring they understand how to apply force effectively.
4. Integration into Prevention Programs
   Incorporate flywheel training as part of pre-season or rehabilitation programs, prioritizing eccentric exercises to strengthen the athletes’ weak points.

Sample Flywheel Training Session for Hamstrings

Warm-Up:

• Dynamic joint mobility (10 min).
• Glute and core activation exercises (plank, glute bridges, etc.).

Main Session:

1. Flywheel Leg Curl: 3 sets of 6 repetitions (focusing on the eccentric phase).
2. Flywheel Hip Extension: 4 sets of 8 repetitions.
3. Flywheel Hip Thrust: 3 sets of 10 repetitions.

Cool-Down:

• Static stretches for hamstrings and glutes (10 min).

Final Considerations