Force-Velocity: Relationship and Application

Strength training is a terrific way to improve athletic performance. Don’t believe me? Here’s proof: in the 1960s, only a handful of pro and college teams hired full-time strength & conditioning (S&C) coaches. Fast forward to today, nearly every major sports team and college program have at least one full-time S&C coach on staff.

How S&C coaches determine the ideal methods to use with their athletes

Every sport is unique and imposes demands that are specific.  Football linemen need to generate massive amounts of force to hold the line of scrimmage while basketball players need a ton of speed qualities to blow by a defender. Therefore, it’s important to know a) what the demands of the sport/athlete are (sometimes these may differ from one athlete to another) and b) how to optimize training to meet these demands.

The force-velocity curve is the foundation that every strength coach must understand in order to improve their athletes’ performance. 

The 5 segments that make up the force-velocity (F-V) curve

It’s important to understand that the F-V curve depicts concentric muscle action during a movement/exercise. Concentric simply means the shortening phase of a muscle contraction (for example, the upward phase of a squat or bench press).

Figure 1.

Take a look at Figure 1. Notice that at various parts of the force-velocity curve, different types of training components can be targeted.

Let’s dissect each segment of the force-velocity curve and provide an example of an exercise that fits into that segment.

Maximum Strength (90-100% of 1RM):
  • Exercise: Squat
  • Lift will be very heavy
  • Force applied will be very high
  • Velocity of the lift (i.e. the speed) will be very slow
Strength Speed (80-90% of 1RM)
  • Exercise: Squat
  • Lift is heavy
  • Force applied will be high
  • Velocity of the lift will be slow but because this is a submaximal load, there should be a greater intention to move the load quickly
Peak Power (30-80% of 1RM)

Maximizing peak power is tricky. Why? Because there are so many variables that determine peak power output and each athlete has a different power profile. The prescribed loading range is so varied (30-80% of 1RM) because one athlete may elicit peak power values at 70% of 1RM while another at 50% of 1RM. Some studies have even noted peak values occurring at 0% of 1RM during a jump squat. We’ll expand more on power and how it relates to the F-V curve in next week’s post.

Speed Strength (30-60% of 1RM)
  • Exercise: Ballistic jumps squats  (i.e. jumping with a barbell on your back)
  • Moderate amount of force generated
  • Velocity is towards the higher end.
  • Important to note that there is still a strength component here, but the emphasis is starting to shift towards speed of movement
Speed (<30% of 1RM)
  • Exercise: Pent jumps (i.e. standing long jump)
  • Low levels of force generation
  • Movement occurs at a much higher speed

But I always lift heavy…


Figure 2.

What happens if you’re someone who spends most of the time lifting heavy and at slow speeds? You will no doubt develop a tremendous amount of strength (if you practice proper recovery/regeneration techniques because this type of training is extremely taxing from a nervous system perspective) but your sport specific speed, what you do on the field, court etc., may actually decrease. Figure 2 depicts what happens to an athlete’s F-V curve when they focus primarily on strength training.

 I have the need for speed…


Figure 3.

Although most of us probably don’t spend enough time training at the high velocity end of the F-V curve, there are certain sports that focus  entirely on speed work. For instance, sprinters (100 m, 200 m etc.) do a ton of sprint/speed work - but they have to because of the high complexity involved in sprint mechanics. Look at Figure 3; this is the result of focusing solely on speed training.

Many experienced S&C coaches suggest putting sprinters through heavy strength training programs later in their careers. The theory - once a certain level of speed is achieved through velocity-specific training, further increases in sprint times can occur through the activation of high-threshold motor units; and this can only happen through heavy strength training.

What do strength coaches aim to do with most athletes?


Figure 4.

The goal of most training programs is twofold (Figure 4):

  1. Increase the amount of force an athlete can produce at any given velocity. This will effectively shift the athlete’s F-V curve upwards.
  2. Increase speed of a movement using the same load. This will shift the athlete’s F-V curve to the right.

Applying the 5 segments of the F-V curve into a practical setting

Incorporating all five segments of the F-V curve is an absolute necessity. This type of system is called the ‘conjugate method’; supported by Louie Simmons, Mel Siff and other pioneers of the S&C World. There are a number of ways to utilize the conjugate method into the organization of an athlete’s training program. Here’s a look at a few of them:

Option 1:

Utilize each of the five segments of the F-V curve in one training session. Ex: Perform a number of exercises in one given workout, each one hitting a different segment of the F-V curve.

Option 2:

Utilize each of the five segments of the F-V curve on different days during 1 training week. Ex: Focus each day on a different segment of the F-V curve.

Option 3:

Utilize each of the five segments of the F-V curve in different phases throughout the year. Ex: Focus each block/phase (generally four weeks in duration) on a different segment of the F-V curve.

All in all, it’s important to understand each segment of the F-V curve and gear long-term training programs to the specific needs of the athlete and sport, maximizing the time spent in the weight room.


1. Siff 2004. Supertraining.

2. Cormie et al 2007. Power vs strength - jump squat training. Medicine & Science in Sports & Exercise.

3. Issurin 2011. New horizons for the methodology and physiology of training periodization.  Sports Medicine.