Velocity Based Training Devices

Velocity based training devices measure how fast a load moves and use that signal to guide training decisions. Most are built around the barbell and the vertical plane. The DynaSled takes the same measurement-led principle into horizontal movement, where sport actually happens, and measures force directly rather than estimating it.

What each device measures and how

Every VBT device captures velocity. Where they differ is in what they do with it and which plane they work in. The table below covers the main categories.

What a velocity based training device actually does

A velocity based training device measures how fast a load moves during a lift or sprint, then uses that velocity to guide training decisions. The core idea is that velocity is honest: a tired athlete moves slower, a fresh one faster, so velocity tells you more about readiness than a fixed percentage of a one-rep maximum does.

Most VBT devices are built around the barbell. They attach to the bar or sit nearby, track the speed of each repetition, and display metrics like mean velocity, peak velocity and power. That information lets a coach or athlete adjust load in real time rather than following a rigid programme written weeks in advance.

Barbell VBT and what it does not cover

Barbell VBT has proven that measurement-led training is better than fixed-percentage guesswork. That principle is solid, and the technology around it has matured. GymAware, Perch and Vitruve all do this job well.

What they do not cover is the horizontal plane: sprinting, acceleration and resisted running. The reason is structural. Barbell devices know the weight on the bar, so they can derive force by assumption. In horizontal movement there is no known weight to start from, so force has to be measured directly or estimated from something else.

Measured force vs estimated force

For barbell VBT, force is trivial: it is the weight on the bar. The device does not need to measure force because the load is known. This is fine for the gym, where the bar weight is fixed and the lift is vertical.

In horizontal movement the situation is different. Sprint profiling tools estimate force by working backwards from velocity, body mass and assumptions about air resistance. The maths is well-established and the estimates can be good, but they are still estimates. The DynaSled takes a different approach: a loadcell sits in the pull line and reads the actual force as the athlete produces it. No reconstruction required.

Why plane matters for velocity based training

Acceleration, sprinting and change of direction are all horizontal actions. Vertical gym lifts develop qualities that contribute to these actions, but they are not the same action. The relationship between a barbell squat velocity and a sprint split is indirect and mediated by a lot of transfer assumptions.

Horizontal VBT closes that gap. Instead of measuring a proxy movement in the gym and hoping it transfers, it measures the actual sport action, the horizontal push against the ground, in the environment it happens. The force-velocity relationship it produces is specific to sprint and acceleration because it is built from sprint and acceleration data.

Choosing a velocity based training device

The right device depends on what question you are trying to answer. If the goal is to manage training load on compound lifts, optimise bar speed and autoregulate intensity in the gym, barbell VBT is the right tool. GymAware, Perch and Vitruve all work. The differences between them are mainly in form factor and integration, not in the underlying measurement.

If the goal is to profile sprint-specific force and velocity, identify force or velocity deficits in the horizontal plane, or track asymmetry relevant to return from injury, a device that measures horizontal force directly is the right tool. Barbell VBT cannot answer those questions because it measures a different plane.

Some programmes will want both. The gym session and the track session are not interchangeable; the data they produce is not interchangeable either. Pairing barbell VBT with a horizontal force device gives a more complete picture than either alone.

The science behind horizontal VBT

Horizontal force-velocity profiling maps the relationship between force and velocity across a range of resisted sprint loads. It tells you whether an athlete is held back by a lack of force production, a lack of velocity, or a combination of both. That distinction drives programming decisions in a way that a single load test cannot.

The DynaSled builds that profile from measured force, not estimated force, which means the profile does not accumulate the modelling error that velocity-only approaches introduce at every step.

Horizontal force measurement for sport

The DynaSled is a friction-resistance sled with a loadcell built into the pull line. It measures horizontal push and pull force directly during resisted sprinting, across natural and indoor surfaces. It brings measured-force horizontal VBT out of the lab and onto the track.

Common questions