Load–velocity profile (sled)
From your free and resisted sprints, the tool builds the athlete's load–velocity line and derives their individual training zones. Loads are personal: they have to be profiled athlete by athlete, not applied uniformly to everyone.
The numbers are yours
Shall we read them together?
What you have calculated stays yours: you need not leave anything to use it. But if you want an opinion on those numbers — what they say, what they do not say, and what to work on first — leave me your email and I will reply myself, personally.
The address is only used to reply to you: no third-party service, nothing passed on to anyone. Privacy
Got it. I will write to you myself, usually within a couple of days.
It did not go through. Try again, or write to me from the contacts on the home page.
The example is a 78 kg athlete with four trials — free, 20, 40 and 60% BM — and fills in every field, so you see a complete profile straight away. Overwrite it with your own data or use «Reset» to start from scratch.
| Zone | Vdec | Velocity | Load %BM | Load kg |
|---|---|---|---|---|
| Waiting for data… | ||||
- Enter the body mass of the athlete (so the loads come out in kg as well).
- Run one free sprint and the resisted sprints. At least three trials are needed: one free (0%), one loaded at 20–30% BM and one at 50–70% BM; more trials = a more solid profile.
- Choose how far the gates go (30, 40, 50 or 60 m): it applies both to the free sprint and to the resisted ones. Under load the athlete gets less far, so the gates you did not record are simply left empty.
- For each sprint enter the cumulative times at the gates (5, 10, 15, 20 m…). The tool computes the mean velocity of every 5 m section and takes the highest as the velocity of that sprint.
- The tool builds the load–velocity line and derives Vmax, the optimal load and the loads for the four zones.
Method & source
With resisted sprinting, velocity falls linearly as load increases (r > 0.95). From the line you get the load that produces a given velocity decrement (Vdec): zones of technique (~10%), speed-strength (~25%), power (~50%, the optimal load) and strength-speed (~75%). A 50% decrement corresponds to peak horizontal power. The table gives the load every 10% of decrement, from 10% to 70%, so you can prescribe in between zones as well.
The key point: the load that produces a given Vdec is highly variable between athletes and cannot be predicted from body mass or Vmax — which is why it has to be profiled individually, instead of giving everyone the same %BM.
Method based on Cahill, Oliver, Cronin, Clark, Cross & Lloyd (2019), Sports 7(5):119 — validated on young male team-sport athletes (≈16–17 years); the absolute load values should be read with that context in mind.