The Science behind Velocity Based Training


Velocity based training (VBT) is a broad category of training, as I have written about before, there are many ways to use velocity in your training but largely these are based on two fundamental training principles:

  • The load velocity relationship
  • Intent to move

Understanding these provides the foundations for almost everything you can do with velocity tracking in your lifting. Let's start with the load velocity profile.

The load velocity relationship

As the load we move get heavier, the speed at which we are able to move gets slower.

This fundamental law of physics is at the core of VBT in the form of the load velocity profile, without this stable linear(ish) relationship VBT wouldn't be anywhere near as versatile as it is.

Load velocity relationship with VBT
This image is licensed under a Creative Commons Attribution 4.0 International License.

The shape and slope of this profile there is plenty we can learn about an individual athlete, their strengths, weaknesses and track their progress over time.

To profile an athlete, simply collect three or more sets worth of velocity data across a range of loads to establish a linear trend line. The equation of this line can then be used for a range of performance tracking, and autoregulation systems.

Who said you wouldn't use high school algebra after school?

At its⁠ most basic level the profile itself is a great performance testing tool, comparing your profile on a given exercise over time to chart whether the line is moving up (faster lifting speeds) and out to the right (heavier weights moved).

This load velocity relationship is the core of using VBT for driving strength adaptations but the same concept can be applied for creating a power-load profile. This is a parabolic relationship with a point of peak power somewhere between 40-70% of 1RM.

Load power profile highlighting peak power
This image is licensed under a Creative Commons Attribution 4.0 International License.

The best part about this way of profiling?

Just collect the data during normal training, no need for a special testing day, just take the velocity of your best rep from every set and plot them to find your force velocity profile.⁠

You can chart your own load-velocity and power-load profiles using my free VBT spreadsheet, join the VBTcoach newsletter at the bottom of this page.

Intent to move

Intent. A crucial piece of the training puzzle, but rarely given as much love as volume or load.⁠

Lifting heavy weights is great, but the amount of effort you apply to that heavy weight is at least equally as valuable for performance gains, like increasing your vertical jump.

Far too often lifters simply go through the motions, lifting at a comfortable tempo, cruising through.

The simple intention to lift every set as fast as possible - even if you don't actually move any faster -   will improve your rate of force development, up-regulate the largest and strongest type II motor units, and ultimately increase the transfer of our training into enhanced power. Although it can be tricky to study intent in isolation.

When this is applied to warm up sets it can increase the post activation potentiation of the nervous system priming you for the heaviest sets of the day.⁠

Henneman's size principle illustrated

Do remember to apply controlled intent, violently snapping into hyper-extension, or letting the bar fly and bounce can get dangerous quickly. This method of lifting can be more taxing on the system as a whole, so you might need to reduce your volumes as you experiment with this.

Intent and training with velocity

Movement intent is one of the biggest factor to impact your velocities when lifting. Because of this, the accuracy of our load-velocity profiling is dependant on consistent levels of movement intention during training. If intent fluctuates between sessions it becomes hard to determine whether the weights are moving slowly because you aren't really trying or due to genuine fatigue.

This intent does not have to be at 100% every single rep of every single set, but it becomes tricky to autoregulate if changes in velocity are as much about variable intent as they are about fatigue or training adaptations. I like to lift 95% of my reps above 95% of my maximum intent levels as a general guide, that way I know I'm giving every rep a really good go.

A few hacks to incorporate intent into your training without overcooking your training plan on enthusiasm.

  • First three: Apply maximal intent to your first 3 reps during warm up sets. Consider these the nervous system priming reps and a check in on your readiness. The rest of the set can then be at a more smooth and stable tempo, getting all the other warm up benefits like muscle temperature and range of motion increases. This method makes it hard to track fatigue within a set, but fatigue on warm up sets shouldn't be an issue, just be sure to apply high intent to the entirety of your working sets
  • Rolling averages: VBT autoregulation can feel a bit like you are jumping at shadows. One set is +10% on last sessions velocity, the next your down by 7%. This makes it hard to determine if you are flying or bombing. To solve this, use a rolling one or three month average as the contextual benchmark. Aiming to be above 95% of your one month average velocity on every load gives you a better idea of how you're progress and readiness are tracking.

Are you a velocity based training beginner?

I suggest you start here for the single best way to apply VBT. Or if you have more time, explore my full 10-part fundamentals of VBT series, starting with a practical definition for velocity based training.

Return to the blog home

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