SPEED BOX SQUAT – VARIABLE LOADING

There four primary variables of strength:  absolute strength, speed strength, reversal strength, and dynamic eccentric.  Speed Box Squat, especially with variable loading, will have heavy emphasis on 3 of the 4 primary variables.  This is why this exercise is a staple of the BPS strength program – there is so much that can be accomplished in a single exercise.

 

Double leg squat versus single leg squat

One important aspect to understand is the concept of the double leg squat.  Single leg versus the double leg squat could honestly be one of the most controversial subjects in the industry today.  When reviewing both sides of this “argument”, keep in mind one thing:  all of the properties of the muscle contraction. The dynamic eccentric load of a muscle is a trainable effect and extremely important factor to potentiate power. The reversal strength (deceleration mechanics) against the external load, plus gravity (plus the body in some regards) is a trainable effect and extremely important factor to potentiate power. Isometric strengthening under load at high thresholds after a dynamic eccentric load and reversal deceleration is a trainable effect and extremely important factor to potentiate power. Concentric power off of an isometric pause under load (with the added potentiation of the dynamic eccentric and reversal) is a trainable effect and extremely important factor in overall speed strength and power.

 

These aspects of muscle contraction can be accentuated during double leg squatting.  Because of the numerous independent variables associated with balance and stabilization on a single leg, double leg squatting is far more superior to single leg when it comes to the overall potentiation of power – especially on aspects like dynamic eccentric loading.  Dynamic eccentric loading can be loaded heavy, loaded with heavy variable loading, and the threshold of the eccentric contraction into the potentiation of stored elastic energy at deep bending positions can be increased fast with double leg squatting.  It’s extremely difficult to add variable loading to a single leg squat to help accentuate all of the aforementioned factors.  And it’s almost impossible to hit an efficient reversal deceleration into an isometric pause off of a dynamic eccentric load that is necessary to raise the threshold for potentiation of power.

 

Single leg squatting for absolute strength is phenomenal.  It is probably used a lot more for absolute strengthening of the lower body for the majority of our athletes and general fitness clients. The phenomenon of the bi-lateral deficit is well documented and researched; and thus a single leg squat is a crucial aspect to absolute strengthening.  However when it comes to a dynamic day; and/or the dynamic eccentric, reversal strength, and speed strength aspects of muscle contracting, force loading, and raising the threshold – double leg squatting is far more superior.  Hence, we believe in the concept that both are extremely important and too valuable to be omitted.

 

Speed-Strength versus Strength-Speed

These are concepts that have been well documented and researched.  Vladimir Zatsiorsky has a ton of literature on the subject.  All of the aspects in above related to potentiation of power relates to both Speed-Strength and Strength-Speed:

  • Eccentric strength to optimize dynamic eccentric loading
  • Dynamic eccentric loading to optimize reversal strength
  • Reversal strength to optimize the isometric loading and raise the threshold for the potentiation for concentric power
  • Concentric power is a form of speed-strength and strength-speed
  • Speed-strength and strength-speed is a form of power
  • The success of each of these phases is predicated on the phase immediately before it

 

The main differences between these two aspects in terms of application methods are the loading and the speed of action.  There is standard loading and variable loading; and the combination of the two. From a practitioner’s standpoint, bar speed is a good measurable to ensure you are working in both ranges (Bryan Mann, University of Missouri, 2015):

  • Strength-Speed:75-1.0 m/s
  • Speed-Strength:0-1.3 m/s

 

Note in the videos that this athlete is predominantly working in the Strength-Speed zone.  Even on the upper levels.  This day’s primary focus was to build a foundation of Strength-Speed off of a dynamic eccentric loading, to raise the threshold for efficient Speed-Strength training in succeeding workouts.  Note the bar speed being between 0.8 m/s and 0.9 m/s.

 

Tempo

Building up tempos on a pure dynamic day is a very efficient way to get to the ultimate goal of a high-speed eccentric load; to reversal strength into isometric pause; to pure concentric power with potentiation (the X1X tempo).  Rest periods being between 45-60s.  In a 6-week cycle, and a dynamic day once a week each week in the cycle (off week 4), a tempo and volume might look like this:

  • Weeks 1-2: 5×3 (21X); 5×2 (11X)
  • Week 3:         7×3 (11X); 7×3 (X1X)
  • Weeks 5-6:   8×2 (X1X)

 

Variable load

The accommodating resistance of a variable load is advantageous in many aspects.  First is it will overload the intensity of the dynamic eccentric loading in weeks 3, 5 and 6.  This can be greatly enhanced with bands instead of (or in addition to) chains. It will also provide acceleration through the end range of motion during the concentric portion.  It will also provide for accommodating resistance due to the bar being lighter at the bottom of the squat (where there is a mechanical disadvantage) and heavier throughout the ascent of the squat as the mechanical advantage increases – hence increasing the neural component.  A variable loading mechanism might look like this:

  • Week 1: 5×3 (21X); 5×2 (11X); Single chains
  • Week 2: 5×3 (21X); 5×2 (11X); Double chains
  • Week 3:         7×3 (11X); 7×3 (X1X); Mini Bands plus Triple chains
  • Week 4: No Speed Squats; Download week
  • Week 5:         8×2 (X1X); Light bands + single chains
  • Week 6: 8×2 (X1X); Medium bands + single chains