Strength Qualities (VBT)

Strength is not as simple as some might make it out to be. Strength is highly contextual. Being strong at faster velocities compared to slower velocities may be a more desirable trait to have for your specific sport. Researchers and coaches over the years have sought out ways to quantify different training zones to pinpoint specific strength qualities. Traditionally, these training zones have been looked at from the standpoint of the force velocity curve. However, I think it might be a little more applicable and easier to understand these qualities when extrapolating the findings from a power-velocity curve.


Power-Velocity Curve

The power-velocity curve is derived from the force (load) -velocity curve

One of the advantages of using the power-velocity curve is that you can easily make out a transition point where Power is developed with a large Velocity and small force and where Power is developed with a small velocity and large Force. With this easily quantifiable transition point, we can break down the numbers to see exactly where all of these qualities might fall into play.

***All below qualities are based on my personal profile. There will be individual variances between people and what is applicable for me, may not be applicable for you

Power-Velocity Table

The power-velocity table is the raw data from the power-velocity curve. From the table we can try and breakdown different regions where different qualities might be trained.
*** The table below is from my own squat power-velocity profile. Load is expressed as a % of one rep max and relative power is calculated by multiplying Velocity * % of 1rm = Relative Power 



Max Strength (Blue Zone)

The max strength (blue zone) is determined by power outputs that are greatly influenced by the contribution of load and not velocity. From the table you can see that loads range from 100%-80% and velocities of 0.3 m/s -0.6m/s.


Strength-Speed (Dark Blue Zone)

The strength speed spectrum is determined by higher power outputs than the max strength zone, but majority of the contribution comes from the load on the bar and not the speed of the movement. Loads range from roughly below 80% – above 60% of one rep max with corresponding velocities of roughly above 0.6m/s and below 0.9m/s.


Optimal Power (Yellow Zone)

The optimal power zone is characterized as the “transition zone” between speed-strength and strength-speed. This is where both velocity and force  are acting “optimally” to produce the highest levels of power output. Load is 60% 1rm and a velocity of 0.9m/s.


Speed-Strength (Gold Zone)

The speed-strength zone will have similar power outputs to that of the strength-speed zone. However, velocity will be the primary contributor to high power outputs and force plays a much smaller role. Loads range from below 60% 1rm and above 45% 1rm with corresponding velocities of  above 0.9m/s and below 1.2 m/s


Explosive (Green Zone)

The explosive zone is a little tricky to differentiate and this is in large part due to the small percentages of one rep max being used.  Loads of such little magnitude will only allow for very small ranges of acceleration (probably only half of the movement). It is likely that this zone is best used with some sort of accommodating resistance to increase the acceleration in later ranges of motion.


Speed (grey zone)

I had trouble determining what use this zone has. My guess is that its the type of zone where you are better off just jumping with the barbell than actually performing squats. This type of zone can also be used for reactive/oscillatory type work. Because the load is so low, high speed oscillatory work (contract relax nervous system training) can be done in a safer manner. The low loads allow for higher force dependent impulses to occur and possibly targeting neural firing rates more (just a thought). Loads range from below 20% of 1rm and anything faster than 1.5 m/s



Specific strength qualities may be better trained with specific loading schemes tailored to target the desired quality. The above information can hopefully allow for more accurate application of training stimuli.


All of my own.

You can see how to set up velocity profile by Jovanovic and Flanagan (2014) in other velocity based article

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