The eccentric (lowering) phase of an exercise is a crucial element in strength training and muscle development. It’s associated with greater muscle soreness and contributes significantly to muscle growth (hypertrophy). However, focusing solely on eccentric training can be counterproductive for enhancing overall strength and can even lead to injuries.
This blog post examines the complexities of eccentric training, when it’s beneficial, and when it’s best to avoid it for better results.
The Pros and Cons of Eccentric Training
- Eccentric strength alone is not optimal: Research and practical experience tell us that exclusive eccentric training is often detrimental to absolute strength gains.
- Injury Risk: Most injuries occur during the eccentric phase due to the greater forces involved. Overly focusing on eccentric contractions can increase this risk further.
- Benefits of Controlled Eccentrics: It’s vital to understand that while slow eccentric movements can aid muscle growth, they’re best followed by an explosive concentric phase. This maximizes the power of the stretch-shortening cycle (SSC) – the natural cycle of muscle contraction during movement.
Kinetic Energy and the Stretch-Shortening Cycle
The ability to maximize explosive power relies on an overspeed eccentric phase – using jump-stretch bands or similar tools can help achieve this. In calculating kinetic energy, velocity is far more important than mass. That’s why techniques like the “squat-under” in Olympic lifting are crucial – rapid descents under the bar enhance kinetic energy.
Heavy Lifting and Eccentric Tension
With heavier weights, there’s a tendency to slow down the eccentric phase for more control. This counteracts the benefits of kinetic energy and the stretch reflex. Remember:
- The faster the eccentric, the greater the stretch reflex (within reason). This can have a negative effect on the Golgi tendon reflex, which exists to protect tendons from extreme loads.
- Optimal Speed is Key: As weights increase, the goal should be to find a consistent, optimal eccentric speed regardless of the external load.
- Control vs. Inhibition: Use only enough eccentric muscle tension to control the barbell’s path for a safer, stronger concentric phase.
Using Bands for Optimal Eccentric Tension
Studies using the Tendo unit reveal that ideal speed strength movements in squats and bench presses have eccentric and concentric phases at 0.7-0.8 m/s. For near-maximal weights, that drops to 0.45-0.6 m/s.
Bands can play a crucial role in achieving and maintaining optimal eccentric speed, even as barbell weights increase. This teaches you to better control eccentric movement, preventing excessive tension that can hamper the explosive concentric phase.
Practical Takeaway: Prioritize Explosive Speed
When training for absolute strength, the key with heavy lifts lies in finding and maintaining optimal eccentric speed, regardless of weight. Focus on developing an explosive concentric phase, facilitated by a controlled, rapid eccentric contraction.
Using bands in conjunction with barbells helps build eccentric control and speed, leading to:
- Improved power output by harnessing the SSC
- Maximized kinetic energy and stretch reflex
- Reduced risk of overusing eccentric force, which can inhibit explosive strength
Remember: eccentrics are a tool, but not the only tool. Prioritizing optimal speed, both eccentrically and concentrically, is essential for safer and more effective strength development.
Check out our previous post about Concentric Strength: The Key to Unlocking Deadlift Power.