Train to velocity failure, using velocity stops

In my previous article, we talked about training to failure, meaning you can’t do another repetition. The truth is, that definition of training to failure is a bit outdated. There are other ways to train to failure, like velocity failure, that turn out to be more effective. This article talks about the benefits of training to velocity failure and how to implement it in (velocity based) training.

By Loek Vossen

Velocity failure and velocity stop


Let’s dive right into it and update the true meaning and application of training to failure.

I’d like to suggest the following definition: training to failure is confronting your muscles with their limits.

“Training to failure is confronting your muscles with their limits.”

There are multiple ways of doing that. The most famous way of confronting your muscles with their limits is by lifting a weight until you can’t lift it anymore. I call this repetition failure. We talked about rep failure in the previous article.

In this article I want to introduce a more effective (according to science) method of training to failure: velocity failure.

Training to velocity failure

Let’s start with an example of velocity failure. Say you want to do a box jump. After 10 successful repetitions you get tired and can’t make it on top of the box anymore. That’s because when you fatigue, your movement speed (or power) decreases. This is easy to imagine when thinking about box jumps or running, but also holds true for a set of heavy barbell back squats.

(Bar) velocity decreases when fatigue increases
When you start to fatigue, the velocity of your movement decreases.

Our box jump example is not a repetition failure, since you can still jump. It’s what I call a velocity failure: you can’t build enough speed or produce enough power to reach the box height.

Here’s my definition of velocity failure: you want to move a weight with a certain velocity or power, but your muscles aren’t capable of doing it (anymore).

Before we have a look at how to implement this in weight training and why science shows this is so effective, let’s have a look at what fitness guru AthleanX has to say about it.

How to implement velocity failure

You could implement this velocity target failure in any exercise. Say you want to perform explosive back squats with the aim to move as fast as possible. With a velocity based training device like GymAware RS or FLEX you can easily measure bar speed.

At some point, back squat velocity starts to decrease due to fatigue. You now need to decide at what velocity you’ll stop the set.

Velocity stop (m/s)

One way to do that is by setting a cut-off velocity, or velocity stop. For instance: 1.2 m/s. Once your rep velocity is below 1.2 m/s, you fail to move faster than the velocity stop, and therefore reach velocity failure. As a result, you stop the set. Here’s what that could look like:

Workout set until velocity failure
When you try to move as fast as possible, your velocity will slowly decrease over multiple reps, due to fatigue. Set a velocity stop to decide when you hit velocity failure, and stop the set.

Velocity loss (%)

Another way to look at it is by tracking velocity loss. Say you start your set with a weight that equals 70% of 1RM. If your first rep velocity is 1.5 m/s and your 9th rep velocity is 1.2 m/s, your velocity loss equals 20%. Similar to a velocity stop, you decide at what velocity loss percentage you’ll stop the set.

FLEX Stronger app showing velocity loss percentage during set
The FLEX Stronger app automatically shows your velocity loss (in this case 14%) compared to the previous rep.

It goes beyond the scope of this article to dive deeper into which velocity stop (m/s) or velocity loss (%) is best. Subscribe to our newsletter to learn more about that in the future.

There is one thing I’d like to add before looking at how effective velocity stop and loss is, according to the science.

Every repetition is velocity failure

If you perform every rep with the intention to move as fast as possible, you could say every rep is a velocity failure. Why? Because if you could, you would move faster. You can intuitively understand that by confronting your muscles with their limits every single rep, you give the body an incentive to improve the performance of the muscle, to prevent velocity failure next time.

Science about velocity failure and velocity loss

In my previous article we said that non-failure training is equally effective as repetition failure training. Literature shows that in some cases, velocity failure training does have a greater effect than repetition failure training.

There are not many studies specifically looking at training to repetition failure vs training to velocity failure. However, some studies “accidentally” compare the two, when using a velocity loss percentage that is so high, that participants reach failure. For example:

This study compared the effect of 2 training methods: one with a velocity stop after velocity loss reached 20% (VL20) and one after velocity loss reached 40% (VL40). The VL40 group appeared to train (close to) muscle failure, since they couldn’t finish the set 56% of the time.

During an 8 week program, performing squats with a 70-85% 1RM weight, the VL20 group performed 40% fewer repetitions (!). Still, strength gains were similar between groups. The VL20 group even showed greater improvements in countermovement jumps.

It seems like when power is what you’re looking for, less is more.

Muscle hypertrophy

Both groups showed an increase in muscle volume (hypertrophy), although VL40 elicited a greater hypertrophy. As mentioned in my previous article, hypertrophy seems to be the only reason why you would train closer to failure. Here’s how to do that safely.

You do have to keep in mind that the VL20 group did 40% less repetitions and accumulated less fatigue. Therefore, they need less time to recover and could hypothetically train more often. This is not taken into account when looking at the results.


While the old-fashioned way of looking at training to failure only talks about repetition failure, we discovered a new way of training to failure: velocity failure. This shifts the question from “should I train to failure” to “which velocity stop should I use to determine failure”.

Research shows that using high velocity loss percentages equals training close to repetition failure. This seems to be beneficial when muscle hypertrophy is your goal. Low velocity loss percentages result in less repetitions and can have similar strength gains. They seem to work better when explosive power is what you’re looking for.

Start measuring your own velocity with GymAware RS or FLEX – and subscribe to the newsletter to get a notification when we publish a new article.

Loek Vossen

Loek Vossen

Human Movement Scientist | Content Marketing and Education