Optimizing Strength Training: Velocity, Squat Depth, and Equipment Choices
Squat Depth and Biomechanics
Deep Squats vs. Partial Squats
Deep front and back squats can allow performance-enhancing transfer effects of dynamic maximal strength to dynamic speed-strength capacity of hip and knee extensors compared with quarter squats. With increasing flexion, the wrapping effect leads to enhanced load distribution and force transfer at the knee.
The Wrapping Effect
- The quadriceps tendon contacts the femur beyond 70 degrees of knee flexion.
- This contact decreases the surface area, leading to a decrease in compressive forces.
Partial squats allow for higher production of force. To increase the force level of maximal strength in a more ‘open’ joint angle, it is necessary to use heavier loads. This technique is aimed at increasing maximal strength effort in the main force-producing movements of the exercise. Athletes utilizing partial squats should use heavier loads compared to those who perform full squats.
Equipment Choices in Resistance Training
Free Weights
- Advantages:
- Training goal is to strengthen total body movements and improve coordination between various muscle groups.
- More sport-specific because of the balance required in sports.
- Disadvantages:
- Requires balancing the weight in all directions.
- Makes learning exercise technique more difficult than machines.
Machine Weights
- Advantages:
- Allows movement in one plane and direction, helping to isolate a muscle group.
- Useful when the training goal is to increase strength/power or local muscular endurance.
- Good for rehabilitation programs.
- Disadvantages:
- Only allows movement in a predetermined plane.
- Limits the requirements of the exercise to prime movers.
Strength Classification Based on Velocity
Absolute Strength
Velocity Range: 0.15–0.35 m/s. Examples: Squats (Singles), Isometric Deadlifts.
Accelerative Strength
Velocity Range: 0.45–0.75 m/s. Example: Speed Squats.
Strength-Speed
Velocity Range: 0.75–1.0 m/s. Examples: Full Cleans, Snatches, Loaded Squat Jumps.
Speed-Strength
Velocity Range: 1.0–1.5 m/s. Examples: Hang Power Cleans, Snatches.
Starting Strength
Velocity Range: >1.5 m/s. Examples: Jumps, Medicine Ball exercises.
Specialized Training Methods
Super Slow Resistance Training
Used with submaximal loads where the individual has greater control of velocity. Concentric force production is significantly lower for an intentionally slow velocity of lifting compared with traditional velocity.
- Advantages: May provide some benefit for local muscular endurance and hypertrophy training.
- Disadvantages: Lighter loads may not provide optimal stimulus for improving maximal strength in resistance-trained individuals.
Fast Velocity Training
The goal is to accelerate the load maximally throughout the range of motion during the concentric action to maximize bar velocity.
- Advantages: Moderate-to-high loading is more effective for advanced training than slower velocities, enhancing neuromuscular contributions to the development of muscle power.
- Disadvantages/Limitations:
- Power increases may be specific only to the initial segment of the range of motion.
- Power/speed development throughout the full range of motion is limited because the load cannot be maximally accelerated throughout the entire movement.
Benefits of Olympic Lifting
- Improvement of knee and hip extension power (strength and speed), explosiveness, and rate of force development.
- Improvement of an athlete’s ability to safely and effectively absorb force or decelerate.
- Improvement of kinesthetic awareness and fundamental athletic motor skills centered around the hips and legs.