The Force Velocity Curve and Power Development
The force-velocity curve is an important concept to understand whether you’re a coach or a team sport athlete – one of the most important qualities an athlete can have is power.
Power is the ability to exert a maximal force over the smallest amount of time. Said another way, power is our ability to express our strength quickly. Power is explosiveness. Power is the product of Force x Velocity (P = F x V). Therefore, we can have powerful athletes that sit toward to the force side of the spectrum (rugby) or that sit to the velocity side of the spectrum (basketballers).
One of the goals of strength training for team sport athletes should be to increase their power across multiple levels of the force-velocity curve (as seen in the diagram). Our aim is to shift the entire curve to the right where all levels are enhanced resulting in a more well-rounded athlete.
The force-velocity curve pictured above displays force on the y-axis and velocity on the x-axis. On the top of the y-axis we have maximal strength (think 1RM back squat) and as we move toward the end of x-axis, we have maximal speed or velocity (think 100m sprinters).
In order to optimise most team sport athletes training program, it’s important to hit all stages of the curve (Surf the Curve). This makes for a well-rounded training program and athlete. The ability to produce force rapidly often separates the good athletes from the great.
Therefore, consider the type of athlete you are – if you’re an athlete that is super-fast (leaning towards the max velocity side of the curve) but lack strength, it may be worth increasing the amount of maximal strength work you’re doing in the gym. Developing power via the force velocity curve can be separated into 5 main areas which I’ll outline below.
Maximal Strength <90% of 1RM:
Let’s start on the far left of the curve with maximal strength / force production. The point of these lifts is maximal force production not velocity, and if you’ve ever seen someone attempt a 1RM deadlift you’ll notice it’s not a quick lift. All our attention is on lifting as much weight of possible in a technically safe manner. For max strength lifts you want to stay above 90% of 1RM. Yes, you can get stronger at less, but intensities are usually classified in this range. This is a neurally demanding lift and we need time to let our nervous system recover between sets. The back squat, deadlift and bench press are all great exercises for developing max strength. Keep reps low 1-3 and use extended rest periods up to 5 minutes.
Strength-Speed 80-100% of 1RM:
These movements should be slightly faster than the maximal strength lifts hence why we call it strength-speed. Working around this 80% mark, a good start would be 5-8 sets at 2-3 reps. Our intention on these days is to move the bar as fast as you possibly can. The bar still won’t move super quick but it’s all about your intent – your effort applied into the bar. If your intention is to move the bar as fast as possible, your nervous system switches on, engaging more muscle mass, increasing motor unit recruitment and the training adaptation that goes along with it.
Power 30-80% of 1RM:
By using this reference range of 30-80% 1RM we can move quickly but also have a reasonable size load on the bar. This creates the optimal peak power output (remember P=F x V). It can be tricky when trying to find the optimal loading parameters to optimise power output in certain lifts as there’s individual variation and research has shown different exercises to be more effective at increasing power output depending on the load (a 40% squat jump may not elicit the same power output as a 40% trap bar jump). Exercises such as trap bar jumps or jump squats may provide a higher power output at a lower percentage of 1RM such as 40-50%. While Olympic lifting variations such as a hang snatch may provide the best stimulus closer to 80%. I’d recommend leaning towards lower loads, focus on bar speed (often neglected) and technique before loading up too heavy.
Speed-Strength 30-60% of 1RM:
The focus on the next two areas of the force-velocity curve is speed. So far, we’ve spoken mostly about developing power by increasing our force production capabilities. However, with speed-strength and maximal speed, we want lighter loads and faster movements. On days where our focus is on speed-strength, we want to use exercises such as box jumps, sled sprints, countermovement jumps etc. The use of bands and chains are good here, as they provide varying resistance through the entire range of motion reducing the amount of time we spend decelerating, which means our intention can be on moving faster!
Maximal Speed <30% of 1RM:
At the far-right end of the force-velocity curve is maximal speed. This is the maximum amount of speed you can produce through a specific movement. We want very minimal resistance here and most exercises we don’t want any resistance besides our own body weight. Developing the stretch-shortening cycle is key here so we want to perform exercises such as sprinting, hopping, and assisted sprinting. Our focus is on maximal velocity of muscle contraction, and the best way to get this is through sprinting (Usain Bolt can move at 12+ metres per second – good luck moving a bar that fast). Again, with everything when it comes to power, do less reps, more sets, and have more rest.
A few more pointers when it comes to developing power…
Focus on compound movements – these recruit the most muscle mass
Lifts should be in all planes and use the full kinetic chain (head to toes) – don’t just squat or deadlift up and down, it’s important to move side to side, rotate and move forward and backward. Always think about pushing harder into the ground.
Focus our attention on the posterior chain – these are our GO muscles – back is for go, front is for show.
Focus on intent – always think the bar is heavier than what it is. This will increase the amount of motor units (and therefore muscle fibres) recruited equalling more force production.
Surf the Curve!!